The Islamic University - Gaza
اﻟﺠﺎﻣـﻌﺔ اﻹﺳـﻼﻣـﯿﺔ – ﻏــﺰة
Higher Education Deanship ﻋﻤـﺎدة اﻟﺪراﺳﺎت اﻟﻌﻠﯿﺎ
Faculty of Engineering
ﻛـﻠـﯿﺔ اﻟﮭـﻨﺪﺳــﺔ
Department of Civil Engineering
إدارة اﻟﺘﺸﯿﯿﺪ/ﻗﺴﻢ اﻟﮭﻨﺪﺳﺔ اﻟﻤﺪﻧﯿﺔ
Construction Management
The Effect of Design and Construction's Faults/Errors on Maintenance of UNRWA's School Buildings in Gaza Strip )ﺗﺄﺛﯿﺮ اﻷﺧﻄﺎء واﻟﻌﯿﻮب اﻟﺘﺼﻤﯿﻤﯿﺔ واﻟﺘﻨﻔﯿﺬﯾﺔ ﻋﻠﻰ ﺻﯿﺎﻧﺔ ﻣﺒﺎﻧﻲ ﻣﺪارس اﻻوﻧﺮوا ﻓﻲ
(ﻗﻄﺎع ﻏﺰة Fathi A. Sabha
Supervised by
Dr. Khalid Al Hallaq Dr. Bassam Tayeh A Thesis submitted in partial fulfillment of the requirement for Degree of Master of Science in Civil Engineering – Construction Management The Islamic University of Gaza-Palestine
April, 2015
ﺑﺴﻢ ﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﯿﻢ } ﯾَ ْﺮﻓَ ﯾـــــــﻦ ﯾــــــــــﻦ آ َﻣﻨُـــــــــــــﻮا ِﻣ ْﻨ ُﻜـــــــ ْﻢ َواﻟﱠ ِﺬ ـــــــــﻊ اﻟﻠﱠــــــــﮫُ اﻟﱠ ِﺬ َ َ ِ ﻮن َﺧﺒِـــــﯿﺮ { ت َواﻟﻠﱠــــــﮫُ ﺑِ َﻤــــﺎ ﺗَ ْﻌ َﻤــــــﻠُ َ أُوﺗُــــــﻮا ا ْﻟ ِﻌ ْﻠـــــــــــﻤـ َ َد َر َﺟـــــــــــﺎ ٍ ﺻـــﺪق ﷲ اﻟﻌﻈﯿــــﻢ ﺳﻮرة اﻟﻤﺠﺎدﻟﺔ )(١١
DEDICATION
To The memory of my late beloved father (May Allah grant him eternal rest, Amen);To my affectionate mother who supported me all the way; to my wife for her unlimited encouragement ; to my sons whose innocent energy was and still is a source of inspiration; to all of my friends and colleagues who stood beside me with great commitment; I dedicate this work, hoping that I made all of them proud.
Fathi A. Sabha
I
ACKNOWLEDGEMENT First and foremost I would like to thank Allah for what I am and for everything I have. Next I wish to express my deepest appreciation to both Dr. Khalid Al Hallaq and Dr. Bassam Tayeh whose under their supervision and their advice this thesis was developed. Without their considerable efforts, this thesis could not have been carried out through completion. Thanks to them for being my mentor and for the friendship they offered me. I would like to express my appreciation to the academic staff of the Construction Management Program at the Islamic University-Gaza, especially Prof. Adnan Enshassi, and Dr. Nabil El Sawalhi for their administration and academic support.
A great thanks to my fellows in Infrastructure and Camp Improvement Programme in UNRWA, especially chief of Infrastructure and Camp Improvement Programme Eng . Rafiq Abed. Great thanks to my colleagues in infrastructure and camp improvement programme in UNRWA for their participation in filling the questionnaires, and giving information that supported the case study, especially HFMU / Eng. Diya Skeik, Eng. Azmi Bazazou, Eng. Salam EL-Zebda, Eng. Amjad Jarada, and Eng. Mohammed EL-Uwaini. It is always impossible to personally thank everyone who has facilitated successful completion of the work. To those of you who I did not specifically name, I also give my thanks for motivating me towards my goal. Finally, I would like to thank my mother, wife and lovely children for their love, support and for tolerating the time I spent working with my research.
II
ABSTRACT Due to the Palestine refugee students need free education and due to population growth and increased rate of transfers from Palestinian Authority schools, where the quality of education and infrastructure is low due to conflict, closure, and political turmoil. Many UNRWA school buildings have been built to handle the increase and transfer of students. Thus, many errors will happen, especially during design and construction phase. This will increase the high maintenance costs. Therefore, minimizing these defects will reduce maintenance cost and increase the lifespan of structures. This study aims to improve maintenance performance of UNRWA's schools in Gaza Strip. This improvement will be achieved by minimizing the defects of design and construction phase to increase the lifespan of UNRWA schools buildings. The objectives of this study are: firstly, to identify the main types of defects in design phase. Secondly, to identify the main types of defects in construction phase. Thirdly, to study the effects of design and construction's faults/errors on maintenance of UNRWA's construction schools building at Gaza Strip. Finally, to submit suggestions for solving future maintenance problem related to the school buildings at Gaza Strip. A quantitative (questionnaire survey) and qualitative (case studies) to collect the required data were adopted in this research. Furthermore, this study reveals the important factors, leading to defects in the design stage which includes: lack of workshops to discuss construction problems between project parts, Inadequate QA/QC programs during design stage, Lack of auditing and archiving of approved as-built drawing documents electronically after the completion the project. As a result of this study, it is found out that the important factors that leading to defects in construction stage include: contract awarding on basis of the lowest bidder price, damage due to the multi-use of damaged formwork in the construction industry, insufficient testing procedures during preliminary of water feeding and sewage networks, accelerate the construction to avoid delay, and applying painting layers improperly. Finally, the study found out that the most important effects of faulty design and construction on maintenance of UNRWA schools were: increase in maintenance works, increase in maintenance duration, and increase in maintenance budget. The study recommends several actions to improve maintenance performance of UNRWA's schools in Gaza Strip. The designer must take into account maintenance considerations during the design and supervision stages by choosing of durable materials. The UNRWA should conduct workshops or training courses for designers, supervisor, and maintenance engineers to improve the quality of plumbing and sanitary works, as wills as finishing materials in school buildings. This research recommends that a strict quality assurance and quality control (QA/QC) program to be implemented for the designer and contractor to insure they follow the latest economical and practical specifications. The maintenance team should provide the designers with feedback to reduce the repetition of maintenance work. III
ﻣﻠﺨﺺ اﻟﺒﺤﺚ )ABSTRACT (ARABIC ﻧﻈﺮا ﻟﺤﺎﺟﺔ اﻟﻄﻼب اﻟﻼﺟﺌﯿﻦ اﻟﻔﻠﺴﻄﯿﻨﯿﯿﻦ ﻟﻠﺘﻌﻠﯿﻢ اﻟﻤﺠﺎﻧﻲ ،وﺑﺴﺒﺐ اﻟﻨﻤﻮ اﻟﺴﻜﺎﻧﻲ ،وزﯾﺎدة ﻋﺪد اﻟﻄﻼب اﻟﻤﻨﺘﻘﻠ ﯿﻦ ﻣ ﻦ اﻟﻤﺪارس اﻟﺤﻜﻮﻣﯿﺔ اﻟﻰ ﻣﺪارس اﻻوﻧﺮوا ،ﺣﯿ ﺚ ان ﺟ ﻮدة اﻟﺘﻌﻠ ﯿﻢ واﻟﺒﻨﯿ ﺔ اﻟﺘﺤﺘﯿ ﺔ ﻗﻠﯿﻠ ﺔ وﺗﻌ ﺎﻧﻲ ﺑﺸ ﻜﻞ ﻣﻠﺤ ﻮظ ﻧﺘﯿﺠ ﺔ اﻟﺼﺮاع اﻟﺴﯿﺎﺳﻲ واﻹﻏﻼق اﻟﻤﺴﺘﻤﺮ ،ﻟﻘﺪ ﺗﻢ ﺑﻨﺎء اﻟﻌﺪﯾﺪ ﻣﻦ ﻣﺪارس اﻻوﻧ ﺮوا ،ﻟﻠﺘﻐﻠ ﺐ ﻋﻠ ﻰ ﻛ ٍﻞ ﻣ ﻦ ظ ﺎھﺮة اﻟﺰﯾ ﺎدة اﻟﺴﻜﺎﻧﯿﺔ وﻛﺬﻟﻚ اﻧﺘﻘﺎل اﻟﻄﻼب ﻣﻦ ﻣﺪارس اﻟﺤﻜﻮﻣﺔ ﻟﻤﺪارس اﻻوﻧ ﺮوا ﻓ ﻲ ﻓﺘ ﺮة زﻣﻨﯿ ﺔ ﻗﺼ ﯿﺮة ،ﻟ ﺬﻟﻚ ﺳ ﻮف ﺗﺤ ﺪث اﻟﻌﺪﯾﺪ ﻣﻦ اﻻﺧﻄﺎء ،وﺧﺎﺻﺔ ﻓﻲ ﻣﺮﺣﻠﺔ اﻟﺘﺼﻤﯿﻢ واﻟﺘﻨﻔﯿﺬ ،واﻟﺘﻲ ﺗﺆدى اﻟﻰ زﯾﺎدة ﺗﻜﺎﻟﯿﻒ اﻟﺼﯿﺎﻧﺔ ،ﻟﺬﻟﻚ ﻓﺎن اﻟﺘﻘﻠﯿﻞ ﻣﻦ ھﺬه اﻻﺧﻄﺎء ﺗﻘﻠﻞ ﻣﻦ ﺗﻜﻠﻔﺔ اﻟﺼﯿﺎﻧﺔ وﺗﺰﯾﺪ ﻣﻦ ﻋﻤﺮ اﻟﻤﺒﻨ ﻰ .ھ ﺪﻓﺖ ھ ﺬه اﻟﺪارﺳ ﺔ إﻟ ﻰ ﺗﺤﺴ ﯿﻦ اداء اﻟﺼ ﯿﺎﻧﺔ ﻓ ﻲ ﻣ ﺪارس اﻻوﻧ ﺮوا ﻓ ﻲ ﻗﻄ ﺎع ﻏ ﺰة ،وھ ﺬه اﻟﺘﺤﺴ ﯿﻨﺎت ﺳ ﻮف ﺗﺘﺤﻘ ﻖ ﻣ ﻦ ﺧ ﻼل ﺗﻘﻠﯿ ﻞ اﻻﺧﻄ ﺎء واﻟﻌﯿ ﻮب ﻓ ﻲ ﻣﺮﺣﻠ ﺔ اﻟﺘﺼﻤﯿﻢ واﻟﺘﻨﻔﯿﺬ ﻟﺰﯾﺎدة ﻋﻤﺮ ﻣﺒﺎﻧﻲ ﻣﺪارس اﻻوﻧﺮوا . ﺗﮭﺪف ھﺬه اﻟﺪراﺳﺔ إﻟﻰ :أوﻻ ،ﻟﺘﺤﺪﯾﺪ أﻧﻮاع اﻷﺧﻄﺎء واﻟﻌﯿﻮب اﻟﺮﺋﯿﺴﯿﺔ اﻟﺘﻲ ﺗﺆﺛﺮ ﻋﻠﻰ ﺻﯿﺎﻧﺔ ﻣ ﺪارس اﻻوﻧ ﺮوا ﻓ ﻲ ﻣﺮﺣﻠﺔ اﻟﺘﺼﻤﯿﻢ .ﺛﺎﻧﯿﺎ ،ﻟﺘﺤﺪﯾﺪ أﻧﻮاع اﻷﺧﻄﺎء واﻟﻌﯿﻮب اﻟﺮﺋﯿﺴﯿﺔ اﻟﺘﻲ ﺗﺆﺛﺮ ﻋﻠﻰ ﺻ ﯿﺎﻧﺔ ﻣ ﺪارس اﻻوﻧ ﺮوا ﻓ ﻲ ﻣﺮﺣﻠ ﺔ اﻟﺘﺼ ﻤﯿﻢ .ﺛﺎﻟﺜ ﺎ ،ﻟﺪراﺳ ﺔ ﺗ ﺄﺛﯿﺮ اﻷﺧﻄ ﺎء اﻟﺘﺼ ﻤﯿﻤﯿﺔ واﻟﺘﻨﻔﯿﺬﯾ ﺔ ﻋﻠ ﻰ ﺻ ﯿﺎﻧﺔ ﻣﺒ ﺎﻧﻲ ﻣ ﺪارس اﻻوﻧ ﺮوا ﻓ ﻲ ﻗﻄ ﺎع ﻏ ﺰة .أﺧﯿﺮا ،ﺗﻘﺪﯾﻢ اﻟﻤﻘﺘﺮﺣﺎت ﻟﺤﻞ ﻣﺸﺎﻛﻞ اﻟﺼﯿﺎﻧﺔ ﻓﻲ ﻣﺪارس اﻻوﻧﺮوا ﻓﻲ ﻗﻄﺎع ﻏﺰة .اﺳﺘﺨﺪم ﻓﻲ ھ ﺬه اﻟﺪراﺳ ﺔ أﺳ ﺎﻟﯿﺐ اﻟﺒﺤﺚ اﻟﻜﻤﯿﺔ )اﻻﺳﺘﺒﯿﺎن(واﻟﻨﻮﻋﯿﺔ )دراﺳﺎت اﻟﺤﺎﻟﺔ ( ﻟﺠﻤﻊ اﻟﺒﯿﺎﻧﺎت اﻟﻤﻄﻠﻮﺑﺔ. ﻋﻼوة ﻋﻠﻰ ذﻟﻚ ،أظﮭﺮت ﻧﺘﺎﺋﺞ اﻟﺪراﺳﺔ أن ﻧﻘﺺ ﻋﻘﺪ ورﺷﺎت اﻟﻌﻤﻞ ﻟﻤﻨﺎﻗﺸﺔ اﻟﻤﺸﺎﻛﻞ اﻟﺴﺎﺑﻘﺔ ﺑﯿﻦ اﻟﺘﺼﻤﯿﻢ واﻹﺷﺮاف وطﺎﻗﻢ اﻟﺘﻨﻔﯿﺬ وﻧﻘﺺ ﺑﺮاﻣﺞ ﺿﻤﺎن وﺗﺄﻛﯿﺪ اﻟﺠﻮدة واﻟﺘﺤﻜﻢ ﺑﮭﺎ ﺧﻼل اﻟﺘﺼﻤﯿﻢ وﻧﻘﺺ اﻟﺘﺪﻗﯿﻖ واﻻرﺷﻔﺔ اﻻﻟﻜﺘﺮوﻧﯿﺔ ﻟﻠﻤﺨﻄﻄﺎت ﺑﻌﺪ اﻟﺘﻨﻔﯿﺬ " ﻣﻦ اھﻢ اﻟﻌﻮاﻣﻞ اﻟﻤﺆدﯾﺔ اﻟﻰ أﺳﺒﺎب ﺣﺪوث اﻟﻌﯿﻮب واﻷﺧﻄﺎء ﻓﻲ ﻣﺮﺣﻠﺔ اﻟﺘﺼﻤﯿﻢ. ﻛﻤﺎ اﺳﺘﻨﺘﺠﺖ اﻟﺪراﺳﺔ أن " ﺗﺮﺳﯿﺔ اﻟﻌﻄﺎء ﻋﻠﻰ اﻗﻞ اﻻﺳﻌﺎر ﻟﻠﻤﻘﺎوﻟﯿﻦ وﺗﻜﺮار اﺳﺘﺨﺪام اﻟﺸﺪات اﻟﺨﺸﺒﯿﺔ اﻟﺘﺎﻟﻔﺔ ﻟﻠﺨﺮﺳﺎﻧﺔ ﻓﻲ اﻻﻧﺸﺎء وﻧﻘﺺ اﺟﺮاء اﻟﻔﺤﻮﺻﺎت اﻟﻼزﻣﺔ اﺛﻨﺎء اﻋﻤﺎل اﻟﺘﺄﺳﯿﺲ ﻟﻠﻤﯿﺎه واﻟﺼﺮف اﻟﺼﺤﻲ و اﻟﺴﺮﻋﺔ ﻓﻲ اﻧﺠﺎز اﻻﻋﻤﺎل ﻟﺘﻔﺎدي اﻟﺘﺄﺧﯿﺮ ،وﻋﺪم ﺗﻨﻔﯿﺬ طﺒﻘﺎت اﻟﺪھﺎن ﺑﺸﻜﻞ ﺻﺤﯿﺢ " ﻣﻦ اھﻢ اﻟﻌﻮاﻣﻞ اﻟﻤﺆدﯾﺔ اﻟﻰ أﺳﺒﺎب ﺣﺪوث اﻟﻌﯿﻮب واﻷﺧﻄﺎء ﻓﻲ ﻣﺮﺣﻠﺔ اﻟﺘﻨﻔﯿﺬ. واﺳﺘﻨﺘﺠﺖ اﻟﺪراﺳﺔ أن ﻣﻦ أھﻢ ﺗﺄﺛﯿﺮات اﻷﺧﻄﺎء واﻟﻌﯿﻮب اﻟﺘﺼﻤﯿﻤﯿﺔ واﻟﺘﻨﻔﯿﺬﯾﺔ ﻋﻠﻰ ﺻﯿﺎﻧﺔ ﻣﺒﺎﻧﻲ ﻣﺪارس اﻻوﻧﺮوا ﻓﻲ ﻗﻄﺎع ﻏﺰة ھﻲ :اﻟﺰﯾﺎدة ﻓﻲ اﻋﻤﺎل اﻟﺼﯿﺎﻧﺔ واﻟﺰﯾﺎدة ﻓﻲ زﻣﻨﮭﺎ واﻟﺰﯾﺎدة ﻓﻲ ﺗﻜﻠﻔﺘﮭﺎ . وﻗﺪ أوﺻﺖ اﻟﺪراﺳﺔ ﻋﺪة ﺗﻮﺻﯿﺎت ﻟﺘﻘﻠﯿﺺ ھﺬه اﻟﻌﯿﻮب واﻷﺧﻄﺎء و ﻣﻨﮭﺎ ان ﯾﺄﺧﺬ اﻟﻤﺼﻤﻢ ﺑﻌﯿﻦ اﻻﻋﺘﺒﺎر اﺧﺘﯿﺎر ﻣﻮاد ﻣﻨﺎﺳﺒﺔ وﻗﻮﯾﺔ وﺗﻘﺎوم اﻟﻈﺮوف اﻟﻘﺎﺳﯿﺔ وﺗﻮﻓﯿﺮ اﻟﺪورات اﻟﺘﺪرﯾﺒﯿﺔ اﻟﺨﺎﺻﺔ ﻋﻦ طﺮﯾﻖ اﻻوﻧﺮوا وورﺷﺎت اﻟﻌﻤﻞ ﻟﺘﻮﺿﯿﺢ ﻛﯿﻔﯿﺔ ﺗﺤﺴﯿﻦ ﺟﻮدة اﻟﺘﻤﺪﯾﺪات اﻟﺼﺤﯿﺔ وأﻋﻤﺎل اﻟﺘﺸﻄﯿﺒﺎت واﻟﺘﺄﻛﯿﺪ ﻋﻠﻰ اﺳﺘﺨﺪام ﺑﺮﻧﺎﻣﺞ ﺗﺄﻛﯿﺪ اﻟﺠﻮدة واﻟﺘﺤﻜﻢ ﺑﮭﺎ اﺛﻨﺎء اﻟﺘﺼﻤﯿﻢ واﻻﺳﺘﻔﺎدة ﻣﻦ اﻟﺘﻐﺬﯾﺔ اﻟﺮاﺟﻌﺔ ﻓﻲ ﺗﻘﻠﯿﺺ ﻣﺸﺎﻛﻞ اﻟﺼﯿﺎﻧﺔ وﻋﺪم ﺗﻜﺮارھﺎ.
IV
TABLE OF CONTENTS Dedication ........................................................................................................................... I Acknowledgement ................................................................................................................. II Abstract…………….. ............................................................................................................III Abstract (Arabic) ﻣﻠﺨﺺ اﻟﺒﺤﺚ............................................................................................... IV Table of Contents .................................................................................................................. V List of Abbreviations ......................................................................................................... VIII List of Tables ....................................................................................................................... IX List of Figures ....................................................................................................................... X 1. Chapter 1: Introduction ....................................................................................... 1 1.1 Background and Rationale ....................................................................................................... 1 1.2 Problem Statement ................................................................................................... 2 1.3 Research Aim ......................................................................................................... 4 1.4 Research Objectives ................................................................................................. 4 1.5 Research Importance ................................................................................................ 4 1.6 Research Scope and Limitations ................................................................................. 5 1.7 Brief Research Methodology...................................................................................... 6 1.8 Research Organization ............................................................................................. 7 2. Chapter 2: Literature Review .................................................................................. 9 2.1 Part 1: Maintenance due to design and construction defects.............................................. 9 2.1.1 Introduction ............................................................................................................9 2.1.2 Maintenance Definition ............................................................................................ 9 2.1.3 Maintenance Types ................................................................................................ 11 2.1.4 Building Maintenance Management .......................................................................... 15 2.1.5 School building maintenance ................................................................................... 18 2.1.6 Maintenance Policy ................................................................................................ 20 2.1.7 Developing a Maintenance Policy ............................................................................. 20 2.1.8 Designers' Perspective And Maintenance ................................................................... 21 2.1.9 Owners ' Perspective And Maintenance ...................................................................... 22 2.2 Part 2: Building defects ........................................................................................... 24 2.2.1 Introduction and background.................................................................................... 24 2.2.2 Defects definition .................................................................................................. 25 2.2.3 Causes of defects ................................................................................................... 26 2.2.4 Types of defects in building ..................................................................................... 30
2.2.5 2.2.5.1 2.2.5.2 2.2.5.3 2.2.4.4 2.2.4.5 2.2.6 2.2.6.1 2.2.6.2 2.2.6.3 2.2.6.4 2.2.6.5
Design Defects ............................................................................................................ 31 Defects In Civil Design ............................................................................................... 36 Defects In Architectural Design ................................................................................. 38 Defects due to owner firm administration and staff .................................................. 39 Defects due to construction drawing ........................................................................... 42 Defects due to construction specification .................................................................... 43 Construction Defects…. ............................................................................................. 48 Defects due construction inspection .......................................................................... 49 Defects due to Contractor Administaration ................................................................ 50 Defects due to Architectural and civil construction ................................................ 52 Defects due construction equipment............................................................................ 54 Defects due to construction materials ....................................................................... 55
2.2.7
Effects of faulty/defects on maintenance of school buildings ........................................ 58
V
2.2.8 2.2.9 2.2.10 3. 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.9.1 3.9.2 3.10 4. 4.1 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5 4.2.6 4.2.7 4.2.8 4.3 4.3.1 4.3.2 4.3.3 4.3.4 4.3.5 4.3.6 4.3.7 4.3.8 4.4 4.4.1 5. 5.1 5.1.1 5.1.2 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.2.6 5.2.7
How to Overcome the Effect of Faulty Building Design and Construction ........................ 59 Previous studies .................................................................................................... 61 Summary of chapter .............................................................................................. 66 Chapter 3: Research Methodology ......................................................................... 68 Introduction .......................................................................................................... 68 Research Design .................................................................................................... 68 Research period ..................................................................................................... 71 Research Population ............................................................................................... 71 Sample size .......................................................................................................... 72 Research Location ................................................................................................. 74 Data collection ...................................................................................................... 74 Questionnaire Design ............................................................................................. 75 Pilot study ............................................................................................................ 82 Validity of the Research .......................................................................................... 83 Reliability of the Research....................................................................................... 85 Data processing and analysis .................................................................................... 87 Chapter 4: Data Analysis and Discussion ................................................................ 89 Part 1 : General Information about Respondent ............................................................ 89 Part Two: Factors leading to defects/errors in design stage ............................................. 91 Factors related to defects/errors in civil /structural design .............................................. 92 Factors related to defects/errors in architectural design ................................................. 94 Factors related to defects/errors due to owner administration and his staff ......................... 97 Factors related to defects/errors due to drawing ......................................................... 100 Factors related to defects/errors due to specification ................................................... 101 Comparison between all groups of factors leading to errors/defects in design stage . ......... 103 Ranking and RII of all factors leading to defect/error in design stage ............................. 105 Top ten factors leading to the errors/defects in design stage ......................................... 107 Part Three : Factors leading to defects/errors in construction stage . ............................... 112 Factors related to defects/errors due to lack of inspection............................................. 112 Factors related to defects/errors due to contractor administration and his staff ................. 115 Factors related to defects/errors due to architectural and structural construction ............... 116 Factors related to defects/errors due to construction equipment ..................................... 119 Factors related to defects/errors due to construction material ........................................ 121 Comparison between all groups of factors leading to errors / defects in constriction stage ................................................................................................................. 123 Ranking and RII of all factors leading to errors/defects in construction stage ................... 124 Top ten factors leading to the errors/defects in constriction stage .................................. 127 Part four : Factors related to effects of faulty design and construction on maintenance of UNRWA schools ............................................................................................. 131 Factors related to effects of faulty on maintenance of UNRWA schools . ........................ 131 Chapter 5: Interviews And Case Studies ............................................................... 134 Structured interview ............................................................................................. 134 Introduction ........................................................................................................ 134 Interviews finding ................................................................................................ 134 Case studies ........................................................................................................ 137 Introduction ........................................................................................................ 137 Case study (A): School No.1 .................................................................................. 137 Case study (B): School No.2 .................................................................................. 138 Data collection .................................................................................................... 139 The case studies finding ....................................................................................... 139 The major findings of the case studies are summarized as follows:- ............................... 142 Summary ........................................................................................................... 142
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6. Chapter 6: Conclusions and Recommendations ..................................................... 147 6.1 Introduction ........................................................................................................ 147 6.2 Conclusions ........................................................................................................ 147 6.2.1 Results related to objective 1.................................................................................. 147 6.2.2 Results related to objective 2.................................................................................. 148 6.2.3 Results related to objective 3 . ................................................................................ 148 6.3 Recommendations ............................................................................................... 149 6.4 Further Recommended Studies ............................................................................... 150 References…...................................................................................................................... 152 Annex 1: Questionnaire in English .......................................................................................... 159 Annex 2: Questionnaire in Arabic ........................................................................................... 166 Annex3: Descriptive statistics of all factors related to defects in design stage ........................... 172 Annex 4: Descriptive statistics of all factors related to defects in construction stage ................ 175 Annex5: Descriptive statistics of all factors related to effects of faulty on maintenance ........... 178
VII
LIST OF ABBREVIATIONS BRE
Building Research Establishment
CICIP
Chief of Infrastructure and Camp Improvement Program
GS
Gaza Strip
ICIP
Infrastructure and Camp Improvement Program
PCU
Palestinian Contractors Union
QA
Quality Assurance
QC
Quality Control
RII
Relative Importance Index
SPSS
Statistical Package for the Social Sciences
UNDP
United Nations Development Program
UNRWA
United Nations Relief and Works Agency
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LIST OF TABLES ............................................................................ 11 Table 2.2: Causes of building defects in different countries ............................................................ 29 Table 2.3: Common building defects and their symptoms (Fixit institute, 2010). ................................ 32 Table 2.4: Defects/Errors building in design stage and list of Reference ............................................ 46 Table 2.5: Defects/Errors building in construction stage and list of Reference .................................... 57 Table 2.1: Definition of maintenance building
Table 2.6: Effects of faulty on maintenance and list of Reference ............................................................. 59 Table 3.1: Sample size and response rate of the study populations. ............................................................ 74
...................................................................... 74 Table 3.3: List of defects/errors in design stage. ........................................................................... 76 Table 3.4: List of defects/errors in construction stage. .................................................................. 79 Table 3.5: List of effects of faulty design and construction to maintenance UNRWA school. ............... 81 Table 3.6: Profile of respondents interviewed for pilot study and content validity. ..................... 82 Table 3.7: Correlation coefficient between one field and all the fields. .............................................. 84 Table 3.8: Half Split Method. ................................................................................................... 86 Table 3.9: Cronbach’s Coefficient Alpha. ................................................................................... 87 Table 4.1: Classification of respondents ...................................................................................... 89 Table 4.2: The organizations and respondent background and characteristic ...................................... 90 Table 4.3: Rank and RII of factors related to defects/errors in civil /structural design .......................... 92 Table 4.4: Rank and RII of factors related to defects/errors in architectural design ............................. 95 Table 3.2: Geographical distribution of the sample.
Table 4.5: Rank and RII of factors related to defects/errors due to owner administration .......................... 97 Table 4.6: Rank and RII of factors related to defects/errors due to drawing ............................................. 100 Table 4.7: Rank and RII of factors related to defects/errors due to specification................................ 101 Table 4.8: Rank and RII of group of factors related to defects/errors in design stage ............................... 103 Table 4.9: Ranking and RII of all factors leading to errors/defects in design stage ............................. 105 Table 4.10: Top ten factors leading to errors/defects in design stage ............................................... 107 Table 4.11: Rank and RII of factors related to Defects due to lack of inspection ............................... 113 Table 4.12: Rank and RII of factors related to defects due to contractor administration and his staff .... 115 Table 4.13: Rank and RII of factors related to Defects due architectural /structural construction ......... 117 Table 4.14: Rank and RII of factors related to Defects due construction equipment .......................... 120 Table 4.15: Rank and RII of factors related to Defects due construction materials ............................ 121 Table 4.16: Rank and RII of groups related to defects / errors in construction stage ........................... 123 Table 4.17: Ranking and RII of all factors leading to errors/defects in construction stage ................... 125 Table 4.18: Top ten factors leading to errors/defects in construction stage ....................................... 127 Table 4.19: Rank and RII of factors related to effects of faulty on maintenance ................................ 131 Table 5.1: Profile of Interviews ............................................................................................... 134 Table 5.2: Summary of case study No (1) information ................................................................. 137 Table 5.3: Summary of case study No(2) information .................................................................. 138 Table 5.4: Rank group of factors related to defects/errors in design stage (case study) ....................... 141 Table 5.5: Rank group of factors related to defects/errors in construction stage (case study) ............... 142 Table 5.6: Common defects/errors in schools No.1 and No.2 (case study)
IX
...................................... 144
LIST OF FIGURES
Figure 2.1: Type of maintenance : ( Al-Khatam, 2003) ............................................................. 13 Figure 2.2: Overview of maintenance: (Lind and Muyingo, 2012) ........................................... 14 Figure 3.1: Flow Chart of Research Methodology. ..................................................................... 70 Figure 6.1: Effects of faulty design and construction on maintenance of UNRWA school buildings .................................................................................................................................... 149
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1. Chapter 1: Introduction 1.1
Background and Rationale
Due to the fast developing in Gaza city and the increasing in the population every year, many building construction project have been built to overcome the demand of both the public and private sectors. In order to meet the high demand of both the public and private sectors in new building constructions in a short space of time, it is anticipated that many defects and errors will arise, especially during design and construction phase. This will unavoidably result in high maintenance costs. Similar problem with UNRWA schools the needed of Palestine refugee students for free education and due to population growth and increased rate of transfers from Palestinian Authority schools, where the quality of education and infrastructure is suffering significantly as a result of ongoing conflict and closure, as well as political turmoil, many UNRWA school buildings have been built to overcome the phenomenon of both increase and transfer the number of students in a short space of time, it is expected that many faults will happen, especially during design and construction phase. this will lead to increase the high maintenance costs (UNRWA infrastructure and camp improvement program, 2014 ) . Maintenance issue often arises when the building performance is not meeting the standards and quality designed (Ali et al., 2013). As a result of the growth of school building with the lack of building standards, more maintenance, rehabilitation, and renovation work have become necessary to ensure the serviceability and safety of the constructed schools. In addition, the existing schools need to be sustained as long as possible. Therefore, ways must be found to reduce the maintenance cost works due to ageing of the buildings while keeping the same quality. Maintenance costs of a building during their functional lifetime could easily exceed the initial outlay of a new building. Therefore, it’s important to consider maintenance aspects at the very outset of the life cycle of a building because decisions made at planning, design and construction stages have a large effect on the maintenance costs and works incur later in the life cycle of a building. Aged building doesn’t necessary have to be associated with high maintenance cost as a new building with numerous defects from faulty design and construction could easily equal or surpass the maintenance cost of an aged building (Hoe, 2009). Gaza Strip is considered a densely populated area that made construction industry and number of buildings increased rapidly after the establishment of the Palestinian Authority in 1994. As known, Gaza Strip has a costal location which makes many reinforced concrete structures susceptible to aggressive actions due to the high relative humidity and high salts concentration (Abu Hamam, 2008). 1
Many concrete structures in GS suffer from serious defects/errors that increase maintenance costs and decrease the life span of the structure. Abu Hamam (2008) stated that structures in the Gaza Strip may face several defecting criteria in their life, starting from their design stage to the service stage; these normally include faults in design, faults in the construction process, defects in materials, chemical attacks, etc. Therefore any design or construction faults/errors may affect negatively on maintenance performance of the residential buildings. As a result, buildings should be designed and constructed to meet higher building standards which demand longer life span and control of the decaying processes. Building maintenance costs increase and decrease according to the designers and construction contractor’s education, experience and comply with the specifications and standard (Al-Khatam, 2003). This study attempts to identify civil and architecture faults/errors design and construction in UNRWA school buildings at Gaza city that contributed to possible solution to overcome these errors and effect on maintenance cost . 1.2
Problem Statement
United Nations Relief and Work Agency for Palestine Refugees (UNRWA) providing free support and services to Palestinian refugees in various fields, especially in the area of education support, and because of the continued increase in the refugee population, the existing schools at different area are very crowded due to the increasing of students. UNRWA has tended to increase the areas of education support and improve the quality of education service provided to the refugees, also increased rate of transfers from Palestinian Authority schools, where the quality of education and infrastructure is suffering significantly as a result of ongoing conflict and closure, as well as political turmoil. More than 200 (two-hundred ) UNRWA schools have been built in Gaza city in a short space of time according to ministry of education statistics in 2013 to avail free education for these students. It is expected that
many faults/errors will happen,
especially during design and construction phase. this will lead to increase the high maintenance costs. Logically, the defects/errors in the design and construction phase for these schools lead to more expenditure on school buildings maintenance process. Therefore, minimizing of these defects will reduce maintenance cost and increase the lifespan of structures.
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Number of school buildings in Gaza Strip suffer from numerous defects that reduce their lifespan. These defects are clear and common that result because of poor design and construction. Huge number of UNRWA school buildings were destroyed either partially or completely by the recent Israeli war on Gaza Strip in 2014, which leads to the urgent need for reconstruction and repair of those buildings (UNRWA website, n.d) A large amount of money from the UNRWA maintenance resource is being used on corrective or remedial measures to buildings in UNRWA to preserve them in optimal function states. Most of the defects and errors are avoidable if maintenance aspects are being considered during design and construction stage of the building. In the most, among of the main causes of high maintenance cost were design and construction errors, not complying with specification. In general, there have several building defects that are commonly found such as erosion of mortar joints, peeling paint, defective plastered renderings, cracking of walls, defective rainwater, roof defects, unstable foundations and tiles settlements. Worldwide, there are a number of challenges to achieve sustainable management like inadequate financial, shortage of fund and bad management. The UNRWA in Gaza spends more money to maintain and repair schools annually. Anyway, most design and construction defects that affect maintenance cost are avoidable if sufficient care is being exercised during design and construction phase. These defects have large implication on maintenance costs and works incurred later in the life of a building. Maintenance personnel should be engaged to inspect the works of designers during design phase and contractors during construction phase to ensure that avoidable defects affecting maintenance are not built into the proposed building. A building with few or no defects arising from design and construction will not burden the building maintenance’s staffs, budgets and works. In order to achieve that, a study needs to be done to identify severe design and construction defects/errors affecting maintenance cost in UNRWA school buildings, so that future schools projects will be given sufficient care on matters regarding to the effects of faulty design and
3
construction on maintenance and suggested several suggestion for solving future maintenance problem related to school building.
1.3
Research Aim
The aim of this research is to improve maintenance performance of UNRWA's schools in Gaza Strip, by minimizing the defects of design and construction phase to increase the lifespan of UNRWA schools buildings. To achieve the above aim, the following objectives have been identified as follows.
1.4
Research Objectives
The specific objectives of this research are: 1) To identify the main types of defects/errors in design that affecting maintenance of UNRWA school buildings. 2) To identify the main types of defects/errors in construction phase that affecting maintenance of UNRWA school buildings. 3) To study the effects of design and construction's faults/errors on maintenance of UNRWA's construction schools building at Gaza Strip 4) To submit suggestion for solving future maintenance problem related to the school buildings at Gaza Strip.
1.5
Research Importance
Most design and construction defects that affect maintenance are avoidable if sufficient care is being exercised during design and construction phase. These defects have large implication on maintenance costs and works incurred later in the life of a building. Maintenance staff should be engaged to inspect the works of designers during design phase and contractors during construction phase to ensure that avoidable defects affecting maintenance are not built into the proposed building (Hoe, 2009). Defects in building design and construction increase and decrease according to the designer's and construction contractor's education, experience and compliance with the codes and standards. If these factors are not limited the owner will suffer the maintenance cost at the end. In some cases the law forces the contractor and the designers to share the maintenance and repair expense (Al –Hammad et al., 1997) .
4
A building with few or no defects arising from design and construction will not burden the building maintenance’s staffs, budgets and works. In order to achieve that, a study needs to be done to identify severe design and construction defects affecting maintenance of school buildings, so that future projects will be given sufficient care on matters regarding to the effects of faulty design and construction on maintenance. By conducting this research and identifying the faults and defects which are expected to occur in design and construction for the school buildings, the design firm and the contractor will benefit each according to his discipline. In the meantime the owner will minimize maintenance expenditure and the substantial life of the building will increase. The designer will improve the quality of the design by recognizing the faults and avoiding them, and as a result he will have better recognition and liabilities or losses to the owner. The maintenance contractor will improve the quality of work and minimize time delay and expenditure on repair work ; also , he will benefit and have a better recognition in the market.
1.6
Research Scope and Limitations
This research included the following limitations: 1.
This study focused on the UNRWA school buildings that mainly suffer from deficiencies due to poor design and construction practices.
2.
There is a lack of similar previous studies implemented in Gaza Strip.
3.
The study is restricted to a Gaza Strip area.
4.
UNRWA school buildings were considered in the field survey. However, the an investigation was conducted in the school buildings in the Gaza Strip, but other buildings of similar design and construction in the Gaza Strip and elsewhere can benefit from the findings of this research.
5.
The study will be limited to civil and architectural defects in UNRWA school buildings design and construction that affect maintenance only, where electrical and mechanical defects / errors are excluded from this study .
5
1.7
Brief Research Methodology
Stage 1: Literature Review The relevant literature will be reviewed adopted in the research on the subject regarding to building maintenance concepts. Also, types of defects/errors in design and construction stage affecting maintenance of UNRWA school buildings at Gaza strip, and effects of faulty design and construction to maintenance UNRWA school building projects at Gaza Strip. In addition, some maintenance management approaches that aim to reduce the maintenance cost of existing school buildings are highlighted . Stage 2: Structured Interview and Pilot Study It will take the form of structured questionnaire with experts in the field of maintenance of school buildings. Those experts will include project managers, maintenance engineers, design engineers, maintenance contractors, and consultants. This pilot study will be the pre stage to develop the final form of questionnaire. In this stage of the pilot study, there will be an amendment, modifications, omission, addition or developments of the questionnaire to be ready for the final stage of distribution . Stage 3: Final Questionnaire Preparation After the development of all factors based on the structured interview and pilot studies, the questionnaire will be distributed among the maintenance contractors and UNRWA engineers (maintenance, and design ) in this field to obtain their perspectives regarding the mentioned aspects of the main civil and architecture defects/errors that affecting in maintenance of school building through design and construction stage. Target Group: The study will focus on the building contractors who are classified in the field of maintenance building according to the classification of the Palestinian Contractors Union (PCU) . Stage 4: Analysis of Results Statistical analysis and tests will be conducted by using (SPSS) program. It is expected that this study will provide some clarifications for the different type of errors /defects that affecting on maintenance of school buildings .
6
Stage 5: Cases studies A number of UNRWA school building projects in Gaza strip, will be studied, all the issues related to the subject will be studied and discussed such as, type of defects/errors, causes of defects, effects of the defects on maintenance works and the solution to overcome these defects and maintenance problems . Stage 6: Conclusion and Recommendations This stage involves writing up conclusions and suggested recommendations, and recommendations for further studies.
1.8
Research Organization
The thesis is divided into six chapters as follows: Chapter 1 (Introduction): which include a brief overview of research problem emphasizing the importance of design and construction practices in minimizing building maintenance. As well as, it gives a description of the research importance, scope, objectives, methodology, and research organization. Chapter 2 (Literature Review of Maintenance Due to Design and Construction Defects): which include a comprehensive literature review on maintenance perception, maintenance types, defects causes, defects/errors types in design and construction stage in different countries including Palestine and effects of faulty design and construction to maintenance UNRWA school building projects at Gaza Strip. This chapter reflects the importance of design phase in minimizing the UNRWA school buildings defects and maintenance. This chapter discussed the main strategies to overcome the maintenance problems. Chapter 3 (Research Methodology): which include the main steps of the research methodology. This chapter detailed the data collection stage of field investigations to school buildings. Also, the criteria for research sample selection and provided general information about the investigated school buildings was discussed . Chapter 4 (Analysis and Result): which include the statistical method used, table, information deduced from statistical analysis and statistical results, and interpretation of
7
these table and information. It also included the general information of target respondent and contains the ranking by severity index of design faults and construction faults that affect maintenance of school buildings that have been encountered in the investigated school building, which aims finally to identify the main defects in school buildings in GS and their effects on maintenance of school buildings . Chapter 5 (Interviews and cases studies): which include the describes in detail a case study involving education project comprising UNRWA school building in GS to get indepth data about the current errors/defects, which affecting maintenance of school buildings, causes of these errors and solution designed. Case studies aims to extract lessons and principles that can be applied in the industry at large to improve maintenance condition of school building by minimizing the main defects/errors of the school buildings in GS. Chapter 6 (Conclusions and Recommendations): which includes concluded remarks, main conclusions and recommendations drawn from the research work.
8
2. 2.1
Chapter 2: Literature Review
Part 1: Maintenance due to design and construction defects
2.1.1 Introduction Buildings cannot remain new throughout their entire life. All buildings start to deteriorate from the moment they are completed, and at that time the need for maintenance begins. A newly completed building, also requires maintenance. Moreover, it is not possible to replace or rebuild all buildings at one time. The value of a building decreases unless maintenance is carried out on the building (Lateef et al., 2010; Ali et al., 2009). Maintenance works are the only way to maintain and increase the value of the property. Therefore, the need for maintenance will only intensify. Building maintenance and the performance of the building constantly affect people’s comfort and productivity. With the increasing costs of new construction, the effective maintenance of the existing building stock has become even more important. Increasingly, building owners are beginning to accept that it is not in their best interest to carry out maintenance in a purely reactive manner, but that it should be planned and managed as efficiently as any other corporate activity (Arditi and Nawakorawit, 1999: b). Knowing that, it is impossible to produce buildings that are maintenance free, but maintenance work can be minimized by good design and proper workmanship carried out by skilled experts or competent craftsmen using suitable codes of installation and requisite building materials and methods (Adenuga and Iyagba, 2005). 2.1.2 Maintenance Definition Oxford Dictionary defined the verb maintain’ as cause to continue. Maintenance, therefore, is ensuring that physical assets continue to fulfill their intended functions (Lam, 2007). Maintenance is defined as the combination of all the technical and administrative actions, including supervision, intended to retain an item, or restore it to a state in which it can perform a required function (Parida and Kumar, 2006). Maintenance includes the costs of regular custodial care and repair, annual maintenance contracts, and salaries of facility staff performing maintenance tasks. Replacement items
9
of minor value or having a life of less than five years are included as a part of maintenance i.e. replacing light bulbs and repainting are normally included under the maintenance category (Kirk and Dell’Isola, 1995). it may be more descriptive to describe the latter work as “running maintenance”, together with other work such as cleaning floors and windows, replacing broken tiles, etc. Various definitions of maintenance exist among maintenance managers, as defined by various authors and institutions, some of these definition are summarized below at Table 2.1 The issue of building maintenance is a universal issue and is highly considered in the early process of the construction (design) to assure the quality of the building as cited by David Arditi and Manop Nawakorawit (1999:a). Maintenance issue often arises when the building performance is not meeting the standards and quality designed (Ali et al., 2013). Building maintenance follows a specific set of objectives including repair, replacement, renewals, modification, protection that protects the basic materials (i.e external painting and thin coating ), decoration that protects of the internal surface of the building(i.e. painting and etc.), and cleaning for maintaining the internal face of the building (lee, cited in Amani et al., 2012). The other's objectives of building maintenance were summarized by (Alner and Fellows, 1990) as cited by (Hoe, 2009), among of these were : to ensure that the buildings and their associated services are in a safe, to ensure that the building are fit for use, to ensure that the condition of the building meets all statutory requirements, to carry out the maintenance works necessary to maintain the value of the physical assets of the building stock and to carry out the work necessary to maintain the quality of the building. In summary, building maintenance is to ensure the building and its services are in a safe condition; fit for use; to meets all statutory requirements; and to maintain the value and quality of the building (Zainol et al., 2013).
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Table 2.1 : Definition of maintenance building Term
Definition
Quoted source
Maintenance
Work undertaken in order to keep, restore or improve every facility, i.e. every part of the building, its services and surrounds, to a currently acceptable standard and to sustain the utility and value of the facility
(Chanter and Swallow, 1996)
maintenance of machinery and equipment.
The function of keeping assets in, or restoring it to, good operating keeping its original productivity capacity. It includes all the ،condition servicing, testing, inspection, adjustment/alignment, :following actions troubleshooting, calibration, modification and overhaul ،replacement
Maintenance
the combination of technical and administrative actions to ensure the items and elements of a building in an acceptable standard to perform its required foundation
the a process of reservation and restoration activity of the structure and Maintenance of a components of a building. It covers the whole building which includes building toilets, rooms, walls, roofs, drains, doors, windows, floors and also the fix furniture work undertaken in order to keep, restore, or improve every part of the Building building, its services and surrounds, to currently accepted standards, and maintenance to sustain the utility and value of the building .
(Pauw, 1993) as cited by Syce (2007)
(Ali, 2013).
(Zainal et al., 2009) According to British Standards Institute (1984)
Building maintenance
effort undertaken so as to keep, refurbish or improve every element that is every part of a building, its services and surroundings to a currently acceptable condition and to maintain the utility and value of the facility.
Hoe (2009)
Maintenance
the work that is carried out to preserve an asset in order to enable its continuous use and function, above a minimum acceptable level of performance, over its design service life, without unforeseen renewal or major repair activities.
Mohamed (2013)
Maintenance
Actions undertaken in order to reduce the adverse effects of breakdown and maximize the facility at minimum cost.
Lofsten (2006)
2.1.3 Maintenance Types There are several strategic choices available to management to efficiently maintain a building and many alternative decisions to be considered. In general, maintenance of any building may be planned to be implemented at any time, but in some cases may be compelled to carry out at a specific time. The maintenance divided into planned or unplanned maintenance which have been identified by the types of the conducted
11
maintenance. As shown in Figure. 2.1, types of maintenance include the following (AlKhatam, 2003) :
Corrective maintenance: It consists of repairs to the building and equipment due to natural wear and tear or faulty preventive maintenance. It covers all activities, Including replacement or repair of an element that has failed to a point at which it cannot perform its required function. Corrective maintenance is sometimes referred to as failure-based or unplanned maintenance. With equipment problems, there may be a question as to whether the particular item should be repaired or replaced.
Preventive maintenance: Preventive maintenance was introduced to overcome the disadvantages of corrective maintenance, by reducing the probability of occurrence of failure and avoiding sudden failure. This strategy is referred to as time-based maintenance, planned maintenance or cyclic maintenance. Preventive maintenance tasks are performed in accordance with a predetermined plan at regular, fixed intervals, which may be based for example an operating time. The aim is to catch small problems before they become big and expensive.
Service maintenance: It includes maintenance items requested by the tenants or occupants. It also includes emergency items.
Routine maintenance: It includes general maintenance to the common areas. These items are not tenant requested, but are necessary to keep the building in good condition.
Deferred maintenance: Occasionally, the necessary maintenance is put off until a later date; this is called deferred maintenance. Contributing to the delay might be budget limitations, owner preference, the availability of parts, or inclement weather.
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Figure 2.1: Type of maintenance (Al-Khatam, 2003)
13
Lind and Muyingo (2012) illustrated that maintenance can be divided into a number of specific types. Maintenance has been classified in a number of different ways described in Figure 2.2.
Figure 2.2: Overview of maintenance (Lind and Muyingo, 2012)
Also, Dennis (2009) classified maintenance as follow:
Preventive is maintenance which is carried out to prevent an item failing or wearing out by providing systematic inspection, detection and prevention of incipient failure. Preventative maintenance is usually programmed.
Statutory maintenance is when plant such as lifts, fire systems, fume hoods and air conditioning systems are serviced and maintained in accordance with legislative requirements.
Corrective maintenance can be defined as maintenance that is required to bring an item back to working order when it has failed or worn out.
Backlog maintenance is maintenance that is necessary to prevent the deterioration of an asset or its function but which has not been carried out.
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2.1.4 Building Maintenance Management Horner et al. (1997) defined building maintenance as “work undertaken in order to keep, restore or improve every part of a building, its services and surrounds, to a currently accepted standard, and to sustain the utility and value of the building. Current building maintenance strategies, whether based on planned or unplanned maintenance, are most likely to be budget driven. This means that maintenance is not carried out according to actual need, but is dictated by financial priorities decided at the time or during the previous 12 months. Lam et al. (2010) illustrated that in Britain, building maintenance activities have reached a level of 50% of all annual construction activities. While there has been a significant increase in refurbishment works both in the UK and in the Italian construction industries in the last 30 years, the gross value of general trades such as decoration, repair and maintenance, and construction work at minor work locations has been increased over the past 5 years in Hong Kong. Olajide and Afolarin (2012) showed that historically, in both public and the private sectors, the maintenance is seen as an avoidable task which is perceived as adding little to the quality of the working environment, and expending scarce resources which would be better utilized. Management of any process involves assessing performance, and maintenance management of buildings is no exception. In order for any maintenance manager to measure performance and set priorities, the organizational needs have to be considered i.e. the function and performance of buildings and their appropriate standards will be dependent on the user’s perception and their primary needs. Dhillon (2002) mentioned that since the industrial revolution, maintenance of engineering equipment in the field has been a challenge. Although impressive progress has been made in maintaining equipment in the field in an effective manner, maintenance of equipment is still a challenge due to factors such as size, cost, complexity, and competition. A maintenance department is expected to perform a wide range of functions including:
Planning and repairing equipment/facilities to acceptable standards.
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Performing preventive maintenance; more specifically.
Developing and implementing a regularly scheduled work program for the purpose of maintaining satisfactory equipment/facility operation as well as preventing major problems.
Training maintenance staff and other concerned individuals to improve their skills and perform effectively.
Reviewing plans for new facilities, installation of new equipment, etc.
Developing contract specifications and inspecting work performed by contractors to ensure compliance with contractual requirements.
Keeping records on equipment, services, etc.
Bin Hashem (2006) showed that the main responsibility of maintenance unit is to maintain all the facilities and infrastructures. The main job is to make sure the supporting system for activity and work process in the office is perfect. The main supporting system such as lift system, air conditional system, air intake and outlet, electrical system, firefighting system, plumbing and sanitary system, cleaning services, civil and structural building, landscape, safety security, pest control, telecommunication system should be working properly without any disturbance that could affect the entire office work process. Queensland Department of Public Works (2011) states that the following conditions are not classified as maintenance:
Improvements and upgrading to provide additional or new service capability or function.
Upgrading to meet new statutory requirements.
Major refurbishment and replacements to extend the useful life of the building.
Restoration of the entire building to operational condition after total or near total failure (e.g. resulting from natural disasters).
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Work performed under warranty or defects liability period.
Operational tasks to enable occupancy and use (e.g. cleaning, security, waste management) and supply of utilities (e.g. energy, water and telecommunications).
According to Al-Khatam (2003), maintenance can be done in different stages. Each stage will have different characteristics as follows:
Planning and Design Stage: the planning and designing of the facility should be based on the identified function and be as maintenance free as possible. In this stage a lot of money can be saved with the proper plan and design. For this reason, the building manager and maintenance personnel should be consulted during the early stages of the building design.
Construction Stage: in order to achieve minimum level of maintenance during the building life, work performed during the construction phase must be done with the highest quality in term of workmanship. As a result, expert contractor should be selected to perform the project.
Maintenance Stage: in this stage, maintenance is performed after the building has been constructed and occupied, periodic maintenance will be upon the function of each component in the building, which may be daily, weekly, monthly and yearly.
Maintenance management involves the organizing of resources to deal with the problem of maintenance within an estate of resources to obtain maximum benefits from the investment. Maintenance management can further be divided into building maintenance technology and building maintenance management. Building maintenance management is regarded as describing how a system of maintenance effort could be organized to deal with the problems of building maintenance as a whole. It recognizes that an effective program to curb maintenance costs must start with the design of the building itself and must eventually justify itself, not only in terms of minimizing the costs of maintenance, but also in maximizing the benefits of the investment (Son and Yuen, 1993). Consequently, the function of building maintenance is to maximize the aesthetics and economic values of a building as well as to keep the health and safety of the occupants. Some of the specific maintenance objectives are as follows (Magee, 1988):
17
Perform daily housekeeping and cleaning to maintain a properly presentable facility.
Develop and execute a system of regularly scheduled maintenance actions to prevent premature failure of the facility and its systems and components.
Complete major repairs based on lowest life-cycle cost.
Identify design and complete improvement projects to reduce and minimize total operating and maintenance costs.
Operate the facility utilities in the most economical manner while providing necessary reliability.
Provide for easy and complete reporting and identification of necessary repair and maintenance work.
Monitor the progress of all maintenance work.
Perform accurate cost estimating to ensure lowest cost solutions to maintenance problems.
Maintain a proper level of material and spare parts to support timely repairs.
Accurately track the costs of all maintenance work.
Schedule all planned work in advance, and allocate and anticipate staff requirements to meet planned and unplanned events.
Maintain complete historical data concerning the facility in general and equipment and components in particular.
Continually seek workable engineering solutions to maintenance problems.
2.1.5
School Building Maintenance
School buildings are one of the important facilities for getting basic knowledge in everyday life. Xaba (2012) defined a school maintenance programme as an organizational activity carried out by the school community in order to prolong the life expectancy of school buildings, its furniture and equipment for normal use, (and) should be systematic and pro-active”. Maintenance school building is a continuous operation to keep the school buildings, furniture’s, and equipment's in the best form for normal use. The maintenance of the school building is a daily activity of the institution and its personnel. It is an important factor in the delivery of teaching and learning education system as a whole. Maintenance activity covers the whole building envelope which includes the building
18
structures, roofing, building exterior and interior, wall, columns and fixed furniture. Need analysis in maintenance research shows that many school buildings have small cracks in concrete columns, beams, structural walls, and floors but there is no major damage involved. This is due to the fact that many school buildings are more than 25 years old (Zainal et al., 2009). Ali et al.(2013) focused on identifying school building elements with design defects and established the relationship between design defects and difficulties in carrying out maintenance works. He concluded that the most common design defects that have caused high maintenance cost were building facade and missing slot underneath the floor slab which led to more defects. Also, he concluded that the design defect which causing high maintenance cost for schools in Penang does not at critical stage and still under control. Physically, the schools are of good condition with minor design defects that do not affect the building structural safety but perhaps contribute to a little occupancy safety and health issue. The study recommended that expert maintenance personnel shall be employed in the design stage to minimize design defects in school projects which in turn minimize the cost of building maintenance. Lavy and Bilbo (2009) studied and identified how facilities maintenance is planned, managed and carried out by large Texas public schools. Facility deficiencies result from numerous causes, including extreme environmental conditions and lack of maintenance funding. maintenance funding. Many facility problems are not due to geography or socio-economic factors; instead, they are related to maintenance staffing level, training, and management practices. This means that a school must have a facilities maintenance program that is planned, managed and carried out effectively. The study concluded that the poor quality of facilities maintenance management practices exists in large public schools in Texas. Nevertheless, the study, also found that schools following the guidelines set by the US Department of Education tend to have comparatively more detailed and contemporary information about their facility’s condition. As a result, these schools are able to predict the projected needs of the school, including its maintenance needs. Xaba (2012) found that schools generally do not have organizational structures for planned facilities maintenance, nor do they have policies on facilities maintenance.
19
Evidence of facilities maintenance at schools mainly relates to concerns with facilities repairs, (mostly “as the need arises”) and general campus cleanliness; mostly with emergency and corrective forms of maintenance as opposed to crucial preventive maintenance. Therefore, there is a need for interim facilities maintenance committees and, in the long term, a whole-school approach to facilities maintenance that makes facilities maintenance a strategic lever for school functionality. In order to achieve an acceptable condition in schools maintenance, it is necessary to provide sufficient resources in finance, manpower and technology. When the deciding resources are acquired, it is vital to study the types of buildings to be maintained and the standards required to maintain the utility and worth of the building. 2.1.6 Maintenance Policy ARIS (2006) defines maintenance policy as a strategy within which decisions on maintenance are taken. It can be defined as the ground rules for the allocation of resources between the alternative types of maintenance action that are available to management. They are effective decisions which are made on the allocation of human, material and monetary resources. The objective of maintenance policy may be simply stated as keeping buildings in appropriate condition by the most economic means. For instance, what is the most appropriate condition and how best it may be achieved is the substance of maintenance policy. 2.1.7
Developing a Maintenance Policy
A maintenance policy should be developed that will allow the strategy followed and value for money achieved (RICS, 2009). The building maintenance should be a clear statement of the objectives and methods to be employed keeping buildings fit for use and in preserving their asset value. It should define the framework on which all building maintenance and management operations are based and state the life expectancy, or required life expectancy, of the asset. The policy should lay down guidelines concerning acceptable thresholds technical standards, civil and statutory legal considerations (particularly and safety issues), budget control, relations with the users of the buildings the control and execution of maintenance and servicing operations.
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To achieve a locative efficiency, there is a need to prevent or minimize the total cost of maintenance. So, the main target should focus on minimizing of maintenance or at least to reach to preventive maintenance type rather than corrective type. Consequently, avoiding of faults that may occur during design, construction or preventive maintenance is necessary. In short, this means fewer faults lead to lower future maintenance costs. 2.1.8 Designers' Perspective And Maintenance Designers ignore the role of the client and users, particularly naive ones, and make decisions on behave of them (Othman et al. 2004). On other hand, designers ensure that they have carefully considered the client needs and accommodated all of the specified requirements. In fact, this problem is a result of misunderstanding on both sides. Designers have comprehensive knowledge of building design but usually receive little or no feedback after the building is completed (Langston and Ding, 2001). Arditi and Nawakorawit, (1999: a) investigated the relationship between design practices and maintenance consideration which showed that a major issue, during detailed design, is the selection of materials, components, and equipment, and choice is becoming increasingly difficult. There are huge pressures tending to change the nature of building from traditional craft process toward an assembly of factory-made components. This has several consequences. In the first instance, the designer is often faced with having to specify between an extremely large ranges of products, all of which on face value may satisfy performance requirements. Additionally, designers are subjected to a great deal of lobbying to use one product rather than another, and they are bombarded with a plethora of publicity material. This can have two extreme consequences. It may sway the designer to use a new component or equipment, which has not been sufficiently proved in practice, with a potential failure to meet requirements. On the other hand, there may be the opposite reaction, resulting in the designer using a component or equipment, with which he/she is familiar, whether or not it is the right choice in the circumstances. Those planning to build service facilities in particular have much to gain from investigating low-maintenance design options. Incorporating durable, relatively carefree materials in high-use buildings such as hospitals, schools, laboratories, athletic facilities, research centers, and police and fire stations, can yield substantial cost savings 21
over the life of the building. While initial costs vary greatly for low maintenance materials, they are usually more expensive than less durable products. The life cycle for materials such as terrazzo flooring, ceramic tile, and prefinished block, however, may be as long as the life of the building, so that higher up-front costs are eventually paid back and usually exceeded by long-term savings (Ephron, 1989). Ishak et al, (2007) stated that errors in design can be made, however, result in unplanned maintenance where the designer fails to understand the build ability of that initial concept. The designer who is aware of the risk is more likely to create buildings that will require only planned maintenance. One way of evaluating the work of the designer is to go through the occupier’s experience of maintenance requirements, even if the building may be regarded as a landmark of urban design. Thus, it can be suggested that there must be a strong relationship between design and maintenance and only those design should be considered good, which were proved as less demanding in terms of maintenance. For more explaining of the link between maintenance and building design, Ramly et al. (2006) suggests that four sectors of building design should be considered and regarded as important if one is to avoid the need for unplanned maintenance at the post-occupation stage. These sectors are:
The main fabric which includes walls, floors, roofs, doors and windows;
Internal finishes which includes ceiling and wall finishes as well as floors;
Special design features such as decorative elements for the doors, windows, glass, air vents and special brick and stone work;
The fourth and the last sector is cleaning and housekeeping of all building components.
2.1.9 Owners ' Perspective And Maintenance Maintenance problems in building facilities are heavily attributed to many factors, whereby the most important ones are design limitations and construction knowledge; owners must be made aware that insufficient funding of design and construction will impact future maintenance capabilities. Owners will continually be challenged to meet greater demand for improved maintenance standard with less staff, less capital and in less time than ever before if nothing is to be done (ARIS, 2006).
22
Clients and end-users blame the construction industry for delivering products that do not achieve their objectives or meet their expectations (Barrett and Stanley, 1999). This could be attributed to a number of reasons. Amongst them, clients and end users are not well represented in the design process. Hence, their objectives and requirements are not well perceived or reflected in design. The increasing recognition of the important role played by clients as the core of the construction process and the driving force for improvement necessitated the importance of achieving their satisfaction through accomplishing their objectives and providing them with best value for money (Latham 1994; Egan 1998; Othman et al., 2004). Building owners place great emphasis on the capital costs of a project at the expense of future running costs Arditi and Nawakorawit (1999:a). The primary initiators of maintenance are the owner and/or user, although other interested parties, e.g. members of public, may exert either a direct or an indirect influence on the amount of work undertaken. The role of building owners with respect to maintenance considerations during design will vary depending on their interest in the use of the building. Their primary aim is to preserve the value of asset to ensure a long-term trouble-free investment capable of providing a continuous and satisfactory return. The objective is to achieve this with minimum expenditure (Lee, 1987). Chanter and Swallow (1996) identified four guiding principles as evolution of a solution to satisfy the requirements for a building that are:
To produce a building that is appropriate and efficient for the functions it houses.
To produce a building that provides the optimum physical and psychological environment for the contents of the building, both animate and inanimate.
To produce a building that strikes an appropriate balance between initial and operation costs.
To produce a building that is consistent with the needs and aspirations of the community at large.
Therefore, the owners should minimize defects that occurred in their projects by focusing on the evaluation phases for these project, which should identify such defects in term of type, causes, and proposed preventions methods to minimize its appearance in the future projects.
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2.2
Part 2: Building defects
2.2.1 Introduction and background Defects within new buildings are areas of non-compliance with the Building code of Practice and published acceptable tolerances and standards. Older buildings, or buildings out of warranty period, may not comply with these standards but must be judged against the standard at the time of construction or refurbishment. Obvious examples of a defect are cracked, damaged or deteriorated brick walls, leaking showers, dampness to a building as well as, excessive sagging to a roof or ceiling. To determine the actual defect requires a professional inspection to find the cause of the problem and to provide the right information for remedial works. Also, defects may exist in areas not accessed by a homeowner such as rooftops. Roof construction can also be affected by fire damage and must be assessed as structurally adequate (ARIS, 2006). A defect within a building may be a result of sub-standard work or lack of expertise at time of construction. Examples are concrete cancer (spalling) and are a result of poor building practices during the 1960's and 1970's, but was amended with a new concrete code in the 1980's. An example of non-compliance is roof construction to buildings older than 1930 where the framework does not comply with current standards. The framework is adequate for the original roof loads, but may be inadequate if the roof is changed. The changing of the roofing can create a building defect (Buys and Roux, 2014) . A defect in an older building may also be caused by lack of adequate maintenance. General maintenance items, such as re -bedding and re- pointing of roof hip and ridge tiles, repainting, normal wear and tear as well as ageing are not a defect. Typical cracks to brickwork and contours of timber floors affected by clay soil movement is not structural and therefore not a defect. A building, product or application can become defective through age and lack of maintenance and professional advice should be obtained to ensure that replacement or works undertaken are using materials and current systems of application that are appropriate to the building. Examples of building defects are where structural settlement cracks are occurring to brickwork, non-compliance with termite systems, excessive
24
structural sagging to a roof, ill-fitting windows and doors, leaking showers and sagging ceilings (ARIS, 2006). A professional inspection and report will not only provide accurate information on defects, as well as maintenance items that require attention so that remedial works are undertaken to a suitable standard. Defective or inadequate termite systems can allow termites to access a building and cause substantial damage including structural damage to timbers. The various elements and associated service installations that make up a building, together with the contents that allow it to be used and enjoyed, are susceptible to various forms of defect and fault. Past and present research has helped to identify the principal causes, yet many of the problems relating to poor-quality design, construction, repair and maintenance continue to reduce the utility and value of the existing buildings (Hoe, 2009). Defects are categorized as being deficiencies in design, material, construction or subsurface (FindLaw, 2011). The latter can be either patent or latent. Patent defects can be clearly recognized during inspection, the construction period or the project’s defects liability period. Latent defects appear over time, usually once the building has been occupied (Che Mat et al., 2011). It may be argued that the risk of defects occurring in building projects is greater, due to incompetent and unqualified construction professionals. This may be ascribed to the great demand for houses, government policies for job creation and the assistance of emerging construction-industry professionals. This article presents part of the findings of a research project, the primary aim of which is to establish the factors that relate to defects occurring in UNRWA school building at GS. 2.2.2 Defects definition According to Alhajeri (2008), the word ‘defect’ is defined in the Oxford English Dictionary as the lack of something essential or required, an imperfection. It is also defined as “failing in”, as a “shortcoming” or a “blemish” whereby something falls short. The word ‘defective’ is defined as having a defect or defects, i.e. a state of being incomplete, imperfect, faulty, lacking or deficient. In the construction context, the term 25
‘defect’ is generally refers to construction faults that exceed ordinary imperfections, affecting a basic structural element of the building works, and turning the building, installation, or structure into a state of functional ruin . According to the Webster’s Dictionary, a defect is defined as the lack of something necessary for completeness; a shortcoming. It is also defined as an imperfection, fault, or blemish (Ahzahar et al., 2011). A building defect may include any problem that reduces the value of a home, condominium, or building. Building defects can be the result of design errors by professionals, a manufacturing flaw, defective materials, improper use or installation of materials, not conforming to the design by the contractor, or any combination of the above . 2.2.3
Causes of defects
(Stephenson et al., 2002) state that the causes of defects fall into the following basic categories: Natural phenomena such as storms, resulting in damage from floods, exceptionally high winds, lightning, earthquakes; Design errors; Workmanship errors; Faulty materials; Procedural errors; Failure to maintain properly, and Abuse or misuse of the building. They also mention that, although defects caused by ‘natural phenomena such as storms, resulting in damage from floods, exceptionally high winds, lightning, earthquakes’, ‘failure to maintain properly’ and ‘abuse or misuse of the building’ are not the direct responsibility of the designer or builder. It is important to recognize and be aware of these types of problems, as they also provide causes of possible defects. According to Rhodes & Smallwood (2002), the causes of defects can be related to design, construction, procurement and prevailing environmental conditions. They also describe the origin of defects as being inadequate management and technical skills. Weldon (1998) states that building defects or failures may arise due to a variety of factors, including poor design, failure of the material, poor construction, and lack of maintenance. Hoe (2009) concluded that over 90 percent of building defects could be explained partly or wholly as the result of readily identifiable faults in design or construction which could have been foreseen and hence prevented.
26
In the other study, Lee (1987) identified the causes of defects in construction building. some of them describes as follows:
Inadequate brief: the brief may lay down totally unrealistic cost limits or fail to give vital information on the functional requirements of the building. Usually there is no indication of the likely period of use nor of the client’s attitude towards maintenance.
Faulty design decisions: Failure to follow well established design criteria in the choice of structural system and selection of materials; Ignorance of the basic physical properties of materials; Use of new materials or innovative forms of construction which have not been properly tested in use; Misjudgment of user and climatic conditions under which the material will have to perform; Complex details which have a low probability of successful execution on an open building site and Poor communications between different members of the design and construction teams.
Construction method: The conditions under which construction takes place are often far from ideal and, coupled with an emphasis on speedy completion, can result in careless work. some manufacturers of do-called high technology components have little awareness of the rigours of a building site or the standards of accuracy achievable under such conditions. Thus, whilst the materials may be perfect on leaving the factory they can quite easily be damaged in transit, loading and unloading, unsuitable conditions of storage on site and hoisting and placing in position .
User activities: Defects may be caused by unintentional misuse through a lack of information on the correct mode of use, or by deliberate acts of vandalism. Also, certain defects may be related to the social attitudes and financial circumstances of the user.
Maintenance: Incorrect identification of the true cause of a defect, and inappropriate remedial work, will not only do nothing to rectify the original defect but may substantially worsen the condition of the building. Similarly, lack of care in carrying out repairs and inspections may be the cause of defects in previously
27
satisfactory elements. The life of building elements and components can be extended considerably by adopting a planned maintenance approach, so that problems can be identified in their early stages and preventive maintenance carried out to avoid early failure. As shown above, many researches and studies have concluded that design stage win the most important role in eliminating defects. They have also confirmed that there are many and different causes of building defects but poor design, workmanship, materials, and maintenance are the main causes of these defects. The ratios of defects may vary according to the level of compliance with regulations, Building code of practice and standards, using of good materials, experience, etc. Therefore, determining the main causes of building defects through analyzing of some case studies and complaints received from building users are necessary in order to improve the general and special condition in the tender documents. Many researchers explored the causes of building defects in construction projects. Based on the reviewed literature a list of causes of building defects are summarized as shown in Table 2.2 with list of reference in various countries as cited by Al-Farra (2011).
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Table 2.2: Causes of building defects in different countries Country
Causes of building defects
Quoted source
1. Inappropriate materials applied to buildings, poor decisions, and poor rectification work processes. 2.Most of defects are due to biological, meteorological, geochemical, and other natural hazards, human intervention, pollution, mismanagement, inappropriate use, and poor maintenance and remedial work.
(Watt, 1999)
1. 56% of all defects attributed to fair wear and tear. 2. 20% of the defects found were accounted for by poor design decisions. UK
(Ransom, 1981)
3. 20% were accounted to materials and workmanship 1. 58% of defects resulted from faulty design. 2. 35% from operation and installation.
(Seely, 1987)
3. 12% from poor materials and systems. 1. Structural movement due to poor structural design. (The BRE, 1991;
2. Installation method. 3. Workmanship.
Richardson,
4. Maintenance.
1991)
5. Site working conditions. 1. A study of seven buildings showed that 32% of all defect costs Josephson and Sweden
Kuwait
Saudi Arabia
originated from the client and design, 45% from site management,20% from materials and machine.
Hammarlund
2. Regarding design defects, 44% of defect costs were due to lack of knowledge and 50% to lack of motivation.
(1999)
1. In a research on concrete defects in a 20-year-old office building concluded that the main causes of building defects were chemical attack and Poor workmanship.
Qazweeni and
1. A survey of 11 major groups of defects through a literature review and interviews showed that defects were mostly generated by design, specifications, materials, and equipment.
(Assaf et al.,
29
Daoud (1991)
1996)
2.2.4 Types of defects in building Manning (2005) mentions that all types of defects can typically be grouped into the following four major categories: design deficiencies, material deficiencies, construction deficiencies and subsurface deficiencies. Findlaw (2011) describes the major categories as follows: • Design deficiencies : Buildings and systems (designed by professionals such as engineers) do not always work as specified; this can result in a defect. Typical design deficiencies relate to building outside the specified code. A typical design defect is roofs that result in water penetration, poor drainage or inadequate structural support. • Material deficiencies : The use of inferior building materials can cause significant problems such as windows that leak or fail to perform even when properly installed. • Construction deficiencies : Poor quality workmanship can result in long lists of defects, e.g. plumbing leaks. • Subsurface deficiencies: Many houses are built on hills or other areas where it is difficult to provide a stable foundation. A lack of a solid foundation may result in cracked foundations or floor slabs as well as other damage to the building. Subsurface conditions that are not properly compacted or prepared may cause problems, among of them include improper settling to the ground or the shifting of a structure (e.g. a house). Common types of building defects include: structural defects resulting in cracks or collapse; defective or faulty electrical wiring and/or lighting; defective or faulty plumbing; inadequate or faulty drainage systems; inadequate or faulty ventilation, cooling or heating systems; inadequate insulation or sound proofing; and inadequate fire protection/suppression systems. Additionally, dry rot, wood rot, mold, fungus, or termite or vermin infestation may also be the result of a building defect. An expert, such as an engineer or architect will be able to determine whether a construction problem is the result of improper design, material, or workmanship (Ahzahar et al., 2011). Humidity is a major source of problems in buildings worldwide. Moisture can damage the building structure, the finishing and furnishing materials, besides being a direct
30
cause of human discomfort, high indoor humidity promotes mould growth, which can have adverse health impacts on the occupants (Lourenco et al., 2006). Building maintenance prepared through an accurate program of repeated maintenance plays a major role in preventing building defects. Buildings that neglect building maintenance may fall into several defects which may lead to structural failures (Ahzahar et al., 2011). As shown in Table 2.3, (Fixit institute, 2010) summarized the common defects in the building as cited by Enshassi and El-Shorafa (2015). 2.2.5 Design defects Increase of maintenance cost or effort can be attributed to faulty designs. Many of these maintenance problems arise where the design is satisfactory in principle, but has low probability of achievement in practice (Assafe et al., 1996). These are not to be regarded as defects in workmanship but as rather as too high an expectation in design. Anyway, Faults in building design place a heavy burden on the building for rest of its life and there is no compensation for it. In such situations, the responsibility falls on the shoulders of the designer in that they must think carefully with full concentration and consideration towards completion of their design project (Ishak et al., 2007). Faulty design includes all defects that were caused during the early stage of design and particularly in the structural design such as: when designer ignores the spacing for contraction and expansion movement. Such movement causes cracking of the structure, which will result in fractures in pipes or joint failure (Al-Shiha, 1993). In UK, based on the outline of causes derived from the work of Gibson (1979), the implication of design fault on maintenance in buildings has resulted from the following: a) The consequence of thermal movement: Thermal movement in materials can cause cracking in walls or plaster and fractures in structure elements if consideration has not been given to the thermal expansion. Thermal movement can also result in distortion of otherwise impervious joints with the result that penetration of water takes place or there is a loss of adhesion .
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Table 2.3: Common building defects and their symptoms (Fixit institute, 2010).
Common Defects 1. Defective concrete spalling or loose plaster in ceilings
-
2. Water seepage from external wall, window, roof, or from ceiling
3. Structural cracks in walls
-
4. Structural cracks in columns, and beams
-
Symptoms/Phenomenon Surface with water/rust staining, water leakage. Patterned cracking. Bulging, falling off of concrete patches with reinforcement exposed, often rusty. Falling off of plaster/tiles. Water staining. Peeling off of paint or wall paper. Water dripping. Growth of fungus. Defective concrete, plaster or tiles. Rust staining . Cracks that penetrate through finishes into the concrete or bricks . Long, continuous cracks across width of wall. Diagonal cracks at corners of window or door. Cracks with rust staining.
Possible Causes Defective concrete as a result of ageing is commonly found in old buildings. Persistent water leakage may affect the steel reinforcement. Weak concrete caused by the use of salty water in concrete mix, or overloading are also common causes in spalling.
External water seepage could be due to a variety of reasons including cracks on external wall, honey comb concrete, defective sealant at window, defective waterproofing membrane at roof, defective external water and drainage pipes, etc. Structural cracks may be caused by many factors, e.g. excessive movement of the building structure, unwanted ground settlement, serious overloading ,and weaknesses caused by corrosion/deterioration of materials, or damage by accidents, or poor design/ construction, etc. Detailed investigation must be carried out to identify the cause(s) which must be removed or rectified before the cracks are repaired. Cracks that penetrate through finishes Same as item (3) above. down to the concrete or bricks. Spalling .
32
Continue -Table 2.3: Common building defects and their symptoms (Fixit institute, 2010).
Common Defects 5. Non-structural cracks (usually in plaster or other finishes with cement sand rendering as base)
Symptoms/Phenomenon -Hairline cracks. -Multi-directional cracks (shrinkage cracks) -Cracks between panel walls and structural elements e.g. brick wall and beams/columns
Possible Causes Cosmetic shrinkage cracks in plaster or other forms of finishes will affect the appearance only and do not pose any safety concern. They are small hairline cracks developed within the finishes layer not penetrating down to the reinforced concrete structure.
6. Defective external wall finishes/mosaic tiles/ceramic tiles/stone cladding/curtain wall
-Debonding of finishes/tiles from wall structure resulting in “hollow sound” when tapped with a hammer -Cracking of wall surfaces -Bulging with hollow base -Falling off -Cracks -Loosening of parts
The defects could be due to ageing, structural movements, defective workmanship during installation, thermal movement, defective or missing expansion joints, damage by external factors (e.g. falling objects during typhoon), ingress of water into the gap between the finishes or tiles and the structure, etc.
33
b) The consequence of inefficient detailing: Inadequate detailing can cause deterioration of the building facade. In the absence of proper architectural detailing of rainwater discharge from the building face, water may penetrate into the building or stagnate within or on the construction . c) The consequence of improper material selection: Incorrect material selection can add to the financial burden of maintenance, as well as be the cause of thermal movement, distortion, or early failure . d) The consequence of poor design for access for maintenance measures : Poor access for maintenance will cause delay in the repair process that escalates the cost and increases the probability of substandard remedial actions.
In UK, Cook and Hinks (1992) stated that the use of a range of materials for the external envelope of a building can lead to differences in absorption pattern. The different levels of absorption of each material will affect the surface and cause concentration of water runoff with different pattern and staining on the facade. In Malaysia, Ishak et al. (2007) illustrated that thermal expansion, paint decay, cracks, dampness, and staining are the major defects that result from improper material selection and lack of knowledge regarding their physical properties that will effect on future building maintenance. Additionally, dampness, fungi growth, surfaces decay and rot in wood are the major defects that result from poor ventilation design . In Singapore, an analysis of defects in wet areas of buildings by Chew (2005) as cited by Al-Farra (2011) illustrated that mastic failure, the staining of tiles, cracking, water leakage through cracks, water leakage where pipes passed through walls, paint defects, spalling of concrete, unevenness of tile surface and poor pointing are the most defects that result from mistakes made at the design stage, construction phase, maintenance practice and in materials selection. In Abu Dhabi, A filed study was carried out by (Abdellatif and Othman, 2006) to assess building performance which illustrated that : -
Using of unsustainable upper water tanks which are exposed to sun and humidity resulted in getting them rusted and cracked within few years of construction .
34
-
Using of marble and curtain walls entailed increasing the air conditioning capacity to cool the building, which in turn raised the amount of the electric bill, which has to be paid by the end user. Poor workmanship resulted in falling marble tiles causing damages to people and private properties .
-
Using of imported materials created difficulties at the time of replacing damaged items as many of the imported materials became out of production rather than the cost of import.
-
Water leakage represents one of the major problems that affect building performance, disturb end users and maintenance works. This is attributed to a number of reasons. Amongst them: bad workmanship of fixing sanitary ware and sewage pipes, hiding pipes in concealed ducts that make the following up of water leakages a difficult task. In addition, placing of wet areas above electric rooms causes electric short and danger to tenets in cases of water leakages, as well as areas of service rooms are not sufficient to allow the electro-mechanical contractor performs required maintenance works.
-
Narrow ducts that used in ventilations of kitchen, bathrooms and toilets leaded to a big trouble in maintenance works
Maintenance problems can also arise where no attention was given at the design stage of a project to the materials and finishes chosen and whether they are capable of withstanding every day wear and tear. Archifacts (2012) define defect as an aspect of the design, building work or materials which does not conform to the requirements of the contract under which they were procured and categorized into two: latent and patent. The patent defects are caused by normal wear and tear while the latent defects are referred to construction workmanship defects. Ramly et al. (2006) notes that design defects are the faults that have been builtin since the construction of building on the “drawing board”. The deterioration of materials and components that have taken place to some degree is controllable with the decision made during the design stage. They can also arise from faulty design decisions. Faulty design decisions are the most common faults which may be grouped as follows (Gibson, 1979 )
35
-
Failure to follow well established design criteria in the choice of structural system and selection of materials .
-
Ignorance of the basic physical properties of the materials, e.g. failing to make allowance for the differing thermal and moisture movements of materials used in combination .
-
Use of new materials or innovative forms of construction which have not been properly tested in use. This is often the result of uncritical reliance on manufacturer’s literature quoting simulated laboratory tests .
-
Misjudgment of user and climatic conditions under which the material has to perform .
-
Impractical or very difficult to execute design .
-
Poor communication between different members of the design and construction team.
Therefore, it is important that the earlier decisions and initiatives are taken into consideration during the design phase to ensure the proposed building design is maintenance-friendly and sustainable throughout the whole life cycle of a building. Ali et al. (2013) identified types of design defects that contributed to high maintenance cost
for school building in Malaysia. These types include failure to follow well-
established design criteria in the choice of structural system and selection of materials; ignorance of the basic physical properties of the materials; use of new materials or innovative forms of construction which have not been properly tested in use; misjudgment of user and climatic conditions under which the materials have to perform; difficulty in executing the design due to impractical issues; and poor communication between members of the design and construction teams. Therefore, it is important that the earlier decisions and initiatives are taken into consideration during the design phase to ensure the proposed building design is maintenance-friendly and sustainable throughout the whole life cycle of a building. The following is a list of design defects affecting maintenance : 2.2.5.1 Defects in civil design These are the defects caused during the early stage of design and particularly in the structural design such as:
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(1) Ignore design of expansion / contraction / settlement joint and special construction joint: This occurs when the designer ignores the spacing for contraction and expansion movement. Such movement causes cracking of the structure which will result in corrosion of the structural items or cracking of the wall or will affect the look of the building (Al-shiha, 1993 ; Al-Hammad et al., 1997) (2) Ignore the effects of the environment and the loads on structural elements and weather conditions on the materials used: During design, the designer should always select and specify the right material to tolerate the existing weather conditions which will result in less maintenance. The possible environmental influences on materials should be considered at the design stage (Al-Shiha, 1993). Aggressive environmental, abrasive uses of facility, and weather conditions cause early deterioration materials (Al-Hammad et al., 1997 ). Problems result when the designer is used to certain weather conditions and then moves to another place where the weather different without giving consideration to the weather changes. This problem causes the material to deteriorate in a shorter time and leads to defects in other parts of the building, e.g. the internal paint when the external paint does not protect the water from seeping through (Hoe, 2009). (3) Ignore the difference in the adjacent soil layers and variation in soil conditions: Most of the time the soil conditions do not bury in one place. But still there are cases where the soil structures vary in one area. Therefore, the designer should always make sure that the soil conditions are similar to the land built next to it. Also, the designer should always determine the soil conditions for the particular site, with an adequate number of geo-technical tests (Al-Hammad et al. ,1997). Such a problem will cause settling which will cause cracking of structural elements or exterior and interior walls of the building (Al-Shiha, 1993). (4) Ignoring the dynamic loads impact on the stability of the structural building (elevators, air conditioners and generators): This occurs when the building is subjected to physical or mechanical action such as the elevators, the vibration of central air-conditioning units or wind load in high rise buildings. Such problem will result in continuous surface cracking and cannot be prevented unless the impact of induced movement is isolated (Al-Shiha, 1993 ; Al-Hammad et al., 1997).
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(5) Exceeding the allowable deflection limits : This occurs when the designer exceeds the allowable structural span length or does not evaluate the dead and live load effect correctly (Al-Shiha, 1993). Excessive drift under wind loads may impair function or cause cracking of non-structural finishes (Al-Hammad et al. ,1997 ). (6) Ignoring the design for wind effects and design for earthquakes loads effects on the structure : Usually, this happens in a medium size building where it is treated as a two story building. Such factor can cause continuous structural movement which can lead to failure of the structure (Al-Shiha, 1993). Ignoring such factors in the civil design, may cause cycles of stress reversal fatigue cracking problems in the building's life ( Al-Hammad et al., 1997). (7) Inadequate concrete cover on structural elements : Corrosions reach the concrete reinforcement (steel bars) faster if the concrete cover on the steel bars is insufficient, which will result in corrosion of the steel bars and cracking of the concrete element ( Al-Shiha, 1993 ; Al-Hammad et al., 1997). (8) Improperly locating conduits and pipe openings at critical structural locations (sleeves): This occurs when the civil engineer does not review the layout of the mechanical or electrical design, and where the electrical and mechanical designer installs the conduits in a very critical structural elements or damage to the mechanical system of the building, e.g. breakage of water pipes or sewer leakage (Al-Shiha, 1993 ; Al-Hammad et al., 1997) . 2.2.5.2 Defects in architectural design Defects caused during the architectural design stage include: (1) Designing narrow stairs, passage and doors that obstruct the transfer of equipment and maintenance work process : Buildings always need minor and preventive maintenance. Such maintenance requires some tools (ladder, cleaning equipment, etc.). If the designer does not allow enough clearance to get the tools in and out, these minor problems will get bigger and become major problems (AlShiha, 1993 ; Al-Hammad et al., 1997). (2) Selecting of exterior finishing material not relating to climatic condition: The designer should always select the color and type of a building’s exterior finishing material to suit the weather and environmental conditions of the building, e.g. not
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painting buildings with dark colors in a dusty area where they require a lot of cleaning, or using paints which cannot resist heat and humidity (Al-Shiha, 1993 ; Al-Hammad et al., 1997). (3) Ignore the effect of local weather conditions at the building site for the design of the external shapes: Buildings should be designed in such a way to avoid the collection of moisture, water or dust. Such design will help to reduce the maintenance effort required for continuous cleaning and repairing damages due to, e.g. water collection on building's roofs where moisture collection is always a problem ( Al-Shiha, 1993 ; Al-Hammad et al., 1997 ). Designers should specify finishing's which require minimum maintenance and are always available in the market. If the finishing material is not available, the owner should keep a stock and if no stock is available, the owner may be forced to remove the whole surface, e.g. what happens to wall paper if one area is damaged leading to the replacement of the total area to maintain the color match. (4) Designing inadequate expansions joint which don't lead to required purpose between finished faces, ceiling and wall: Designers should specify the location of joints in floor slabs, walls, etc. insufficient joints will cause cracking of the surface or overlapping of tiles or wall cracking due to thermal expansion (Al-Shiha, 1993; Al-Hammad et al., 1997) 2.2.5.3 Defects due to owner firm administration and staff Defects attributed to the owner firm staff and administration are: (1) Inadequate (QA/QC) programs during design stage : Quality control is the process used to control, inspect, test and record procurement, fabrication and installation in conformance with contract document (Al-Khatam, 2003). Qualified owners usually implement quality assurance/quality control (QA/QC) programs during their design to reduce the number of defects and mistakes in the design. The (Q.A/Q.C) program requests that one group do the design and another group review it to highlight design defects (Al-Shiha, 1993 ; Al-Hammad et al., 1997 ) (2) Lack of technical updating and adequate training of staff and lack of awareness of construction technology: Owners should update and expose their engineers staff to the latest construction material and methods in the market. In
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addition, they should maintain and keep track of the new materials redundant or construction methods and make sure that they perform adequately in the existing building environment (Al-Shiha, 1993 ; Al-Hammad et al., 1997). The availability of properly trained personnel in the type of maintenance work is necessary for completing the work correctly. Poor or lack of training is likely to have an impact on the building maintenance cost. Ali et al. (2010) stated that, the lack of maintenance personnel training is one of the reasons for poor operating practices in maintenance management. Poor operating and maintenance practices often lead to human error and consequently the occurrence of poor quality of maintenance outcomes. Poorly trained staff would result in the performance of defective work, reduced productivity and accidents. Ultimately, these consequences will contribute to a high maintenance cost (Colen and Lambrecht, 2012 ). Some of the maintenance work requires certain type of technology. Maintenance staff who are inadequately trained in the use of the required technology will end up with faulty maintenance and rework, which will increase the cost of maintenance. (3) Lack of adequate budget for maintenance work: It is very important that building owners, when they prepare the annual budgets, include enough financial allocation for maintenance work, as it is a critical and needed function. In the absence of financial support for maintenance work required, the building will not be maintained properly (Al-Khatam, 2003) . Quality of maintenance activities often affects the building maintenance cost. According to Ali (2009), the quality of maintenance activities is influenced by the amount of budget allocation in each task. Budget controlling in maintenance activities is essential to manage the maintenance cost expenditure. In fact, sufficient resources, especially finance is needed for maintenance work to have good maintenance actions and to sustain the required standard of building functions (Lee and Scott, 2009). (4) Lack of technical background and experience of the designer: Efficient and cost effective building design depend to a great degree on the designer's technical background. The more the designer is exposed to the latest design technology, the better his output is and the less maintenance is required. Qualified designers should
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have office and field experience. If the designer has only office experience, he will not experience the faults happening at the construction site during the design implementation (Al-Shiha,1993 ; Al-Hammad et al., 1997 ) . (5) Ignore the designer to the properties, characteristics and behaviors of materials: One of the major causes of building deterioration and other unsatisfactory features of many buildings is the bad understanding of the nature and behavior of materials (Al-Khatam, 2003). The designer should always study the properties of construction materials before they specify them in their design drawings. A material and proven to be good in one place or country, could be bad in another place because of the change of climatic conditions, or the poor experience of the construction contractor with this material. This leads to the improper installation or performance of the material (Al-Shiha, 1993; Al-Hammad et al., 1997). (6) Misjudgment of environmental and climatic conditions: Most designers require from the owner the land details only. They neglect to request more information on the land location to know if it is in a rainy area, where a good drainage system is required, or in a windy area, where some precaution is required. It is very important for the designer to be aware of all the climatic details related to the design to avoid any maintenance problem that could arise from climatic conditions (Al-Shiha, 1993 ; Al-Hammad et al., 1997). (7) Lack of documentation and archiving of the previous maintenance: Documentation of maintenance work is essential for future maintenance of similar work. This documentation could be used as a base for prospective maintenance to avoid implementing procedure that would result in high cost of maintenance. Documentation of maintenance work provides for effective accounting procedures for the contractor ( Hassanain et al., 2013). (8) Poor communication and coordination between the design team and the crew of maintenance / implementation: Coordination between the construction phase and the operation and maintenance phase will reduce the amount of re-work and maintenance that will be needed afterwards. Maintenance contractors can raise concerns on aspects including installation of systems and construction methods that would affect the amount and cost of maintenance in the future (Assaf et al., 1996 ).
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(9) Bad feedback and the lack of workshops to discuss construction problems between the design, supervision and implementation staff: Communication between the maintenance and design groups is important to get the views of the maintenance staff on issues related the selection of material, systems and equipment. Lack of communication would result in the repetition of faulty design, which affects the cost of maintenance (Hassanain et al., 2013). 2.2.5.4 Defects due to construction drawings These are the defects due to design faults in the construction drawings: (1) Lack of references (cross sections and detailed): Building design drawings should always show the cross section and detailed references clearly on the drawings. Lack of references will lead the contractor to carry out the job according to the contractor's own understanding and experience (Al-Shiha, 1993 ; Al-Hammad et al., 1997 ) . (2) Conflicts of architectural and civil drawings: Most of the designs are performed separately for each section, for example civil drawings or mechanical drawings, without consulting other related parties. E.g. when the mechanical engineer makes some changes which will affect the civil work, this action can lead to conflicts which are usually left to the contractor to find and solve (Al-Shiha, 1993 ; AlHammad et al., 1997 ). (3) Poor and inaccurate details (detailed sections): In discussing defects in buildings the charge is often levied that many of the faults stem from poor detailing. An explanation of this is that sometimes the designer leaves the details of his vision to be worked out by draughtsman who are either inexperienced or unqualified to take this responsibility. Also in some cases, the designer leaves out some details to be decided on the site ( Hoe, 2009 ). Most of the building designs lack cross sections, details of structural elements, joints, plumbing, drainage and electrical connections. These are left to the contractor's judgment and experience. As a result, the contractor may perform the job with poor quality and cause many maintenance defects which can only be discovered during building operation (Al-Shiha, 1993 ; Al-Hammad et al., 1997 ).
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(4) Lack of auditing and archiving of approved as-built drawing documents electronically: Inaccuracy of as-built drawings. Construction contractors sometime do not provide accurate as-built drawings to the owner. Such drawings are used by the maintenance contractor. Discrepancies between actual conditions and conditions reflected in the as-built drawings would draw the maintenance contractor to wrong assumptions. This would result in the maintenance contractor spending unnecessary time on the jobsite and would ultimately increase the cost of maintenance ( Hassanain et al., 2013). 2.2.5.5 Defects due to construction specification In addition to clear construction drawings, construction specifications should be clear also. Defects can be caused by the following: (1) The specification is unclear and unrealistic: Poor specification will cause the contractor to perform the job to his own standard and interpretation. For an unqualified contractor it means poor quality work and more maintenance defects ( Al-Shiha, 1993 ; Al-Hammad et al., 1997 ) (2) Not specifying to appropriate materials and specifications: Weak or inadequate designs specify the materials in general without detailed specifications. Such a problem will allow the contractor to provide the material to meet the general guidelines, where it will not serve the job correctly. For example, if the design specifies only sealant without specifying the type, the contractor will select the cheapest ( Al-Shiha, 1993 ; Al-Hammad et al., 1997). (3) Not specifying quality assurance and quality control (QA/QC) procedures: Most construction specifications do not specify the relationship between the owner, the inspector and the contractor, and how to communicate properly to avoid any defect or solve any problem. In addition it does not specify the responsibility of each party. Therefore, the system becomes loose and many defects can happen during the construction stage without correction (Al-Shiha, 1993 ; Al-Hammad et al., 1997 ) . (4) Not specifying to the allowable load limits: This can cause the building to be overloaded either with dead or live loads. For example as using a normal activity room for storage or filing cabinets will cause the load to exceed the allowable limits and cause structural cracks or failures (Al-Shiha, 1993 ; Al-Hammad et al., 1997 ).
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(5) Inadequate experience and expertise to design concrete admixtures: Most designers design the concrete mix to meet the strength requirements and ignore the quality and durability side. The concrete durability is affected highly by the salt content in the sand, water, and aggregate. If the salt content exceeds the allowable limit, the concrete is contaminated and considered as a corrosion environment. In addition, the w/c ratio should be minimized without affecting file workability of the concrete to increase the impermeability( Al-Shiha, 1993 ; Al-Hammad et al., 1997 ). (6) Absence of laws to building maintenance items and specifications (manual or code ): Maintenance manuals are documents provided by the manufacturers, containing information on the product and the procedures for conducting maintenance. Unavailability of such manuals make it extremely difficult for maintenance staff to carry out the work properly and as provided by the manufacturer of the product. This will ultimately have a direct effect on the cost of maintenance ( Hassanain et al., 2013). The objective of the manual is to provide all building users with a common system of maintenance information recording and retrieval for the proper guidance of maintenance operatives, building owners, maintenance involving operatives, costing, and general maintenance. This would act as a common part of the building process and not as a series of isolated events that takes place after the completion of the building ( Al-Khatam, 2003). (7) Lack of local specifications and standards related of requirements of materials and workmanship: The specification and standards are document that clearly and accurately describe the essential technical requirement for materials, which it will be determined that the performance requirements have been met. Such documents may include performance, support, preservation, packing, and making requirements (Patton, 2005 ). Standard and specification documents are extremely important to building maintenance, as it constitutes a schedule of instructions to the contractor and prescribes the materials and workmanship requirement. Projects and facilities are to be constructed as per standard and specifications. Having a uniform specification and standards will ease the construction process as well as maintenance work ( Seeley, 1987 ) .
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It is very important to have on uniform standard and specification to be followed throughout to avoid confusion and loss of skills in trying to understand the procedures called standard ( Al-Khatam, 2003 ). In Saudi Arabia, there are no uniform standard specifications for maintenance activities. This would result in difficulty in controlling the quality of the performed maintenance works. Therefore, it is of essence to establish a uniform standard for maintenance that would compel all contractors to certain minimum requirements of acceptable work ( Hassanain et al., 2013) . A lot of researchers explored type of defects in design and construction stage. Based on the reviewed literature a list of defects are summarized in Table 2.4 with list of reference.
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Table 2.4: Defects in design stage and list of Reference
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Hassanain et al ., 2013
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Ali et al. (2010)
Razak and Jaafar (2012)
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Ali (2009)
Hoe (2009)
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Buys &Roux (2014)
Al-Hammad et al. (1997).
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Al-Khatam (2003)
Assaf et al. (1996)
`Defects/Errors factors
Al-Shiha (1993)
Reference
Defects in civil design Ignore design of expansion / contraction / settlement joint and special construction joint Ignore the effects of the environment and the loads on structural elements and weather conditions on the materials used Ignore the difference in the adjacent soil layers and variation in soil conditions Ignoring the dynamic loads impact on the stability Exceeding the allowable deflection limits Ignoring the design for wind effects and design for earthquakes loads effects Inadequate concrete cover on structural elements Improperly locating conduits and pipe openings at critical structural locations (sleeves)
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Defects in Architectural design Designing narrow stairs ,passage and doors that obstruct the transfer of equipment Selecting of exterior finishing material not relating to climatic condition Ignore the effect of local weather conditions at the building site for the design of the external shapes Designing inadequate expansions joint between finished surfaces
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Defects due to owner firm administration and staff Ignore the provision of programs to ensure and monitor quality Lack of technical updating and adequate training of staff and lack of awareness of construction technology Lack of adequate budget for maintenance work Lack of technical background and experience of the designer
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Continue -Table 2.4: Defects in design stage and list of Reference
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De Silva & Ranainghe
Razak and Jaafar (2012)
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Ali et al. (2010)
Hoe (2009)
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Ali (2009)
Al-Khatam. (2003)
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Buys &Roux (2014)
Al-Hammad et al. (1997).
Ignore the designer to the properties, characteristics and behaviors of materials Misjudgment of environmental and climatic conditions Lack of documentation and archiving of the previous maintenance Poor communication between the design team and the crew of maintenance / implementation Bad feedback and the lack of work and workshops to discuss problems between the design, supervision and implementation Defects due drawings Lack of references (cross sections and detailed) Conflicts of architectural and civil drawings Poor and inaccurate details (detailed sections) Lack of documentation and auditing drawing after execution Defects due specification The specification is unclear and unrealistic Not specifying to appropriate materials and specifications Not specifying quality assurance & control procedures(QA/QC) Not specifying to the allowable load limits Inadequate experience and expertise to design concrete admixtures Absence of laws to building maintenance items and specifications (manual or code ) Lack of local specifications and standards related of requirements of materials and workmanship
Assaf et al. (1996)
`Defects/Errors factors
Al-Shiha (1993)
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2.2.6 Construction Defects Defective construction works can be defined as works that fall short of complying with the express descriptions or requirements of the contract. The majority of modern buildings and civil structures are complex and involve the use of a great variety of engineering methods and processes. Therefore, most projects face the possibility of defects and defective work, which generally result in structures that cannot perform their originally intended roles (Ojo, 2010). Defective construction contributes to both the final cost of a project and the cost of maintenance, which can be substantial. Construction defects usually include any deficiency in the performing of the design, planning, supervision, inspection, construction, or observation of construction of any new home or building. The building is deficient if there is a failure during construction in other words, if the building does not perform in a manner that was intended by the buyer (FindLaw, 2011). construction defaults is another source of the high cost of maintenance which happen during the construction stage and because of construction performance or material used. Faulty construction is one of the most common causes of early deterioration. Common construction faults include inadequate compaction and failure to position the reinforcement, so that it has adequate concrete cover. Under almost any exposure conditions these faults will eventually reduce the service life of the structure as a result of reinforcement rusting after the concrete has become carbonated (Seeley, 1987). As known, the environment of construction is constantly changing and the authorities' actions continuously give new conditions. At the same time, competition between companies may become stronger factor that leads the contractor accept the bid with low margin of profit. Studies show that the cost of defects in construction is in the range of 5-10% of the production cost. Therefore, knowledge of the causes of these defects is necessary for choosing adequate measures. Also, Grosskopf and Lucas (2008) Showed that 69% of all construction defect claims in U.S. are related to moisture penetration through the building envelope. It is injustice to beer this ratio to construction defects lonely, because these defects that relate to moisture penetration may result from using of bad insulation material or poor implementation of these materials.
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Defective construction includes activities such as compaction not done to specifications, which leads to ground movement and eventual failure of foundations. This may lead to the complete failure of a structure ( Zietsman, 2008). In London, The Building Research Establishment (BRE) study shows that only a small portion of defects are attributable to faulty materials in terms of storing or placing in position (BRE, 1984). Some manufactures of so-called high technology components have a little awareness of the rigors of a building site or the standard of accuracy achievable under such conditions. Thus, whilst the materials may be perfect on leaving the factory they can quite easily be damaged during loading handling, unloading, storing or placing in position. Many such defects can be avoided by ensuring greater care at all stages in the process, proper training of operatives and closer supervision. To tackle this problem the construction industry is beginning to introduce the quality assurance techniques developed in other industries such as Quality Assurance (QA) groups and Quality Control (QC)". Poor construction’ is a broad term and it is associated with a number of faults, for example tile fixing, plastering, formwork, plumbing and flooring. Therefore, it can be concluded that in order to avoid all such construction fault which can cause high future maintenance cost at a later stage, it is necessary to revise the traditional mode of procuring building construction by developing a correlation between designer and construction professionals ( Ishak et al., 2007). The following is a list of summary to construction defects affecting maintenance with list of reference. 2.2.6.1 Defects Due to Construction Inspection This section discusses defects due to poor inspection practice, such as: (1) Lack of periodic inspection and monitoring: It is well known that when construction inspection increases, quality increases. Therefore, the maintenance needed is reduced. Most of the building owners ignore this or reject it to save in building expenditure. As a result, cheap or unqualified contractors tend to cheat or perform poor workmanship which at the end affects the quality and increases maintenance cost ( Al-Shiha, 1993 ; Assaf et al., 1996 ).
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(2) Lack of experience and qualification of inspector : Some owners insist on implementing the inspection program. But in some cases it could be that the inspector lacks experience, and the contractor performs the construction as per the inspector's guidance, resulting in poor construction (Al-Shiha,1993; Assaf et al., 1996 ). (3) Ignore of owner monitoring and inspection importance: Most of the owners try to save money by selecting poor quality material, and avoiding inspection because of their ignorance of its importance. As a result, the contractor performs the job on his own without inspection. Some owners avoid inspection by performing the inspection themselves where they can improve little in the quality. But sometime they can affect the quality very badly .E.g. most of the owners ask contractors to add water to the concrete mix to make it more workable which will result into a very porous concrete and cause corrosion of steel bars ( Al-Shiha, 1993 ; Assaf et al., 1996 ). (4) Weakness of inspection rule in implementing corrective actions during construction, and not to give full powers to the inspector : Some owners insist on having an inspection program, but they make themselves the communication channel between the inspector and the contractor. This causes a lot of delays and any corrective action comes late, after the elements are already constructed with poor quality. In this case, the owner should make a direct communication channel with the assurance that the contractor performs the job as per the contract specification and with the approval of the inspector without the owner's full time involvement( Al-Shiha, 1993 ; Assaf et al., 1996 ). 2.2.6.2 Defects Due to Contractor Administration Some of the defects are attributed to the contractor staff and administration such as: (1) Non-compliance with specifications : Contractors tend to do things their own way and few of them follow the construction specification. As a result all the effort spent during the design stage is ignored. Such a problem will increase the maintenance work required during the operation of the building depending on the contractor's experience. If the contractor is well experienced, die maintenance effort needed will be less ( Al-Shiha, 1993 ; Assaf et al., 1996 ).
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(2) The inability to read the drawing : The owner should always make sure that the contractor engineer can read the drawings. Most of the design drawings usually are made in Arabic which the construction engineer is sometimes unable to read. And if he can understand the steel and concrete schedules, he may not be able to read the details or the construction specification or references. Again such a problem depends on the construction engineer's experience. The more experienced he is, the fewer the defects will arise during building operation ( Al-Shiha, 1993 ; Assaf et al., 1996 ). (3) Lack of communication between the designer and owner : If the contractor does not communicate with the owner and the designer for consultation or understanding of the specification, he will depend on his experience in performing the job. This can cause a lot of maintenance defects depending on his experience (Al-Shiha, 1993 ; Assaf et al., 1996 ). (4) Lack of efficiency and expertise of contractor engineers : The Contractor Engineer is the main controller of the construction quality. A qualified technical and administrative engineer can reduce the maintenance cost and time dramatically. Problems are obvious in buildings built with poor management and unqualified engineers (Al-Shiha, 1993 ; Assaf et al., 1996 ). (5) Accelerate in execution to avoid delay and lack of quality : Contractors tend to do the job which needs tools or equipment quickly to reduce rental time. In addition they always tend to select cheap quality material to save money. This problem affects maintenance dramatically. If the contractor selects the right material or performs the job correctly the maintenance required in the future will be reduced (Al-Shiha, 1993 ; Assaf et al., 1996 ). Some services such as corrective maintenance need rapid responses to repair failures. Therefore, the speed of implementation is the important factor. Outsourcing enables an organization to put pressure on a contractor to respond to changes because the contractor should have the resources to perform a service in the agreed time (Greaver, 1999).
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2.2.6.3 Defects due to architectural and civil construction These are the defects caused during the stage of construction such as: (1) Inaccuracy of dimensions and measurement: Inaccurate measurement occurs where the contractor under measures or over measures the sizes of building elements, the location and the material ratios, for example increasing the gap between door and door frame or window and window frame, which causes water and dust leakage. Another case is where the contractor increases the water content in the concrete mix which causes porous concrete and at the end corrosion of steel bars and cracking of the concrete structure (Al-Shiha, 1993 ; Assaf et al., 1996). (2) Lake of soil compaction : Most contractors back-fill the soil in one rather than several layers. Therefore, they only compact the top layer. Since, the bottom soil is not compacted, it will settle at a later stage and cause settlement in the building which will cause continuous cracking in the building walls ( Al-Shiha, 1993 ; Assaf et al., 1996). (3) Excavations with excavations mechanical tools near the existing building: Excavation next to an existing building usually causes soil settlement or vibration to the building's foundation. This action causes continuous wall cracking and requires continuous surface treatment (Al-Shiha, 1993 ; Assaf et al., 1996 ). (4) The damage due to the multi-use of formwork in the construction industry: Damaged form work affects the quality by producing a honeycomb or porous concrete surface or surface cracks which will allow for moisture penetration and cause corrosion of steel bars (Al-Shiha, 1993 ; Assaf et al., 1996 ) . (5) applying of painting layers improperly: Painting is considered a continuous maintenance item either for redecoration or renewal purposes. But sometimes it can become a major maintenance item if it is performed improperly, such as painting on a wet surface or a salty surface or painting in humid weather which will result in the peeling of some of the paint and necessitate complete removal of the original paint and cleaning of the surface ( Al-Shiha, 1993 ; Assaf et al., 1996 ) . (6) Inadequate insulation against water and sanitary works : Water proofing and drainage are two of the items where contractors lack experience. Most of the time are performed wrongly or inadequately, especially at the joints, which results in
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water seepage through the roof ceiling, or block wall. Most buildings lack proper roof drainage or sewer drainage system (Al-Shiha, 1993 ; Assaf et al., 1996 ). (7) Inadequate concrete cover for reinforced concrete : Most of the standards recommend the increase of concrete cover, for example ACI 301 specifies a concrete cover of 2" on beams and columns and 3" in foundations. Most of the contractors perform the job and ignore the importance of concrete cover and even perform the job with less than drawings requirement of one inch, which expedites the rate of reinforcement corrosion and causes concrete cracking (Al-Shiha, 1993 ; Assaf et al., 1996 ) . (8) Cold spacers between the new and old concrete : Cold joints usually happen between new and old concrete or between new cement plastering or old plastering. Such joints if not treated properly will cause surface cracking and water seepage, e.g. in concrete water tanks or on basement walls (Al-Shiha, 1993 ; Assaf et al., 1996 ). (9) Weakness contiguity and coherence between materials : Loss in adhesion results when the material shel-life has expired, e.g. for paints, glue for tiles and PVC fittings, or when the material is used in the wrong place or for the wrong temperature such as using indoor sealants or indoor glue outdoors ( Al-Shiha, 1993 ; Assaf et al., 1996 ) . (10) Remove framework of concrete early before the time allowed: Most contractors if not all would like to remove the form work as soon as possible and some of them even before the allowable time. This can cause permanent deflection and cracking of the structure. These cracks will cause the moisture to reach the steel and cause continuous corrosion and cracking of the building structural elements
(Al-Shiha,
1993 ; Assaf et al., 1996 ). (11) Inadequate curing the casted parts well: Contractors do not spend time and money on concrete curing. It is proven that curing is needed specially in a hot climate to reduce water loss in the concrete, the surface cracking in the concrete elements. Both defects could be a good source for steel bar corrosion. Even if they cure the concrete, they use salty water which will allow the salt to penetrate the concrete elements and cause corrosion of steel bars or cause loss of adhesion
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between cement plastering and the concrete or block surface (Al-Shiha, 1993 ; Assaf et al., 1996 ). (12) Lack of sufficient vibration : Cracking of concrete due to vibrations which take place during the set is a common occurrence. The source of vibration may be passing traffic, pile driving, blasting, and delayed vibratory compaction or accidental vibration of the forms caused by impact of equipment or by careless workers (Al-Shiha, 1993 ; Assaf et al., 1996 ). 2.2.6.4 Defects due to construction equipment (1) Misuse of equipment : Good equipment is the means to perform a good quality job. Therefore, if the equipment is used for the wrong job or misused to perform a job, the quality of construction will be affected, as, for example, when using a wood saw for plastic pipe cutting or a brush instead of a roller for texture paints (Al-Shiha, 1993 ; Assaf et al., 1996 ). (2) Inadequate quality performance and quantity of the equipment: Having enough equipment will help in performing the job properly. Lack of enough equipment will cause the contractor to perform his work by hand where a special tool is required, as when a level hose is used where a theodolite is needed for leveling roof slab for drainage. As a result, the job will be done poorly and requires continuous maintenance after some time of operation. Equipment performance affects building quality. If the equipment or tools are performing poorly, the job will be done poorly and accordingly the building maintenance defects will increase (Al-Shiha, 1993 ; Assaf et al., 1996 ). (3) The lack of the required spare parts elements of the equipment : Poor quality of spare parts and materials. Poor quality of spare parts and materials used in the building components, elements, services or facilities significantly influence the maintenance costs. Al-Hammad et al. (1997) stated that the problems related to the lack or unavailability of the required spare parts, tools or materials to perform maintenance tasks. As a result, poor quality or second hand spare parts are acquired for the maintenance tasks. The use of spare parts is a necessary element in maintenance activities. The quality of these spare parts has a direct effect on the performance of the elements or systems maintained. The use of poor quality spare parts will necessitate re-work, additional 54
maintenance and replacement of the poor quality spare parts. This will have a direct effect on the cost of maintenance (Al-Hammad et al., 1997). (4) Not taking into mind the availability of the equipment used in the maintenance in the local market during implementing: Designer should always design the building according to the available maintenance equipment in the market. The designer should be aware of the equipment available in the market so that he can consider it in his design. Such a problem arises during the cleaning of a building's exterior surface or windows or changing lamps in a very high area. Unavailability of the required equipment will increase the maintenance cost and obstruct preventive maintenance (Al-Shiha, 1993 ; Assaf et al., 1996 ). 2.2.6.5 Defects due to construction materials Maintenance defects could be caused by the wrong selection or use of material such as: (1) Selection of material that is unsuitable for existing climatic conditions: Using material suitable for cold climatic conditions for hot climatic conditions or indoor materials for outdoor conditions, will cause the material to perform inadequately and require replacement in a short time (Al-Shiha, 1993 ; Assaf et al., 1996 ) . (2) Ignore the basic physical and chemical properties of materials: One of the major causes of building deterioration and other unsatisfactory features of many buildings is the bad understanding of the nature and behavior of materials. The failing to make allowance for the differing thermal and moisture movements of materials in combination will adversely affects building functional performance or appearance (Al-Khatam, 2003). (3) use of non-durable materials (which does not stand up): Cheap or low quality material needs continuous repair and maintenance. Maintenance expenditure and efforts can be reduced by selecting good durable materials (Al-Shiha, 1993 ; Assaf et al., 1996 ). (4) Use of expired material: Use of expired material at the construction stage will require the owner to replace it at the operation stage, e.g. expired tile glue or paints (Al-Shiha, 1993 ; Assaf et al., 1996 ).
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(5) The use of new materials are not known and did not examine the details of their quality in construction before in the local market: Today the building designer is faced with new materials with little information about their behavior and characteristics. Also, sometimes relatively untested and after without adequate guarantees. The use of such materials can mean a never-ending cause of maintenance problems (Al-Khatam, 2003). (6) choice of substandard materials that have a poor quality of specifications: Materials selection should meet the performance requirements expected. Using bad quality of materials will cause failure of the materials, which will require replacement, correction or more maintenance works in the future. Selection of inferior materials during the construction stage will cause more problems during the maintenance stage (Ali et al., 2010). Therefore, selection of materials should be in compliance with the performance specification requirements in order to minimize future expenses during maintenance stage (Al-Khatam, 2003; Hassanain et al ., 2013) (7) Ignore determine the time and duration of storage and handling of materials and choosing the appropriate places : Poor handling and storage of material affect the material's quality which will affect the building quality and increase maintenance defects. For example storing building paints outside in the sun will affect paint quality and require replacement in a short time after the building is in operation (Al-Shiha, 1993; Assaf et al., 1996 ). (8) Selection of cheap finishing materials price due to lack of fund :The lowest initial is not necessarily the most economical in the end. For cheaper and substandard materials often require maintenance that is more frequent and may have a short working life than the more expensive alternative (Al-Khatam, 2003).In Saudi Arabia, public maintenance contracts are awarded based on competitive bidding, with the selection of the lowest bidder. The least bidder will try to complete the work with the lowest possible cost in order to generate a profit from the project (Assaf et al., 1998). This will adversely affects the quality of the performed maintenance work (Hassanain et al., 2013).
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A lot of researchers explored type of errors/defects in construction stage. Based on the reviewed literature a list of errors / defects are summarized in Table 2.5 with list of reference Table 2.5: Defects/ Errors in construction and list of Reference
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Ali et al. (2010) De Silva & Ranainghe (2012) De Silva & Ranainghe (2010) Hassanain et al., 2013
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Ali (2009)
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Buys &Roux(2014)
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Hoe (2009)
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Razak and Jaafar (2012)
Al-Khatam (2003)
Assaf et al. (1996)
Defects due to lack of periodic checking and monitoring Lack of periodic inspection and monitoring Lack of experience and qualification of inspector Ignore of owner monitoring and inspection importance Weakness of inspection rule in implementing corrective actions during construction and not to give full powers to the inspector. Defects due to the contractor and his crew management Non-compliance with specifications Unable to read drawing Lack of communication with the designer and owner Lack of efficiency and expertise of contractor engineers Accelerate in execution to avoid delay and lack of quality Poor workmanship and experience of workforce Defects due to construction Inaccuracy of dimensions and measurement Lake of soil compaction Excavations with excavations mechanical tools near the existing building The damage due to the multi-use of formwork in the construction industry Applying of painting layers improperly Inadequate insulation against water and sanitary works
Al-Shiha (1993)
Defects/errors factors
Al-Hammad et al., 1997
Reference
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Continue - Table 2.5: Defects in construction and list of Reference
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Ali et al. (2010) De Silva & Ranainghe (2012) De Silva & Ranainghe (2010) Hassanain et al., 2013
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Ali (2009)
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Buys &Roux(2014)
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Hoe (2009)
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Razak and Jaafar (2012)
Al-Khatam (2003)
Assaf et al. (1996)
Inadequate concrete cover for reinforced concrete Cold spacers/joints between the new and old concrete Weakness in adhesion between old and new materials Remove formwork of concrete early before the time allowed Inadequate curing the casted parts well Lack of sufficient vibration Defects due to construction equipment Misuse of equipment Inadequate quality performance and quantity of the equipment. The lack of the required spare parts elements of the equipment Ignoring maintenance equipment availability in local market Defects due to construction materials Selection of material that is unsuitable for existing climatic conditions Ignore the basic physical and chemical properties of materials use of non-durable materials Use of expired material The use of new materials are not known and did not examine the details of their quality in construction before in the local market choice of substandard materials that have a poor quality of specifications Ignore determine the time and duration of storage and handling of materials Selection of cheap finishing materials price due to lack of fund
Al-Shiha (1993)
Defects factors
Al-Hammad et al., 1997
Reference
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2.2.7 Effects of faulty/defects on maintenance of school buildings Hoe (2009) studied and ranked 7 (seven) effects of faulty design and construction on maintenance of building, these effects were increase in maintenance budget, increase in
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maintenance workforce, increase in maintenance works, increase in maintenance time\duration, lower maintenance quality, difficulty in maintenance planning and increased maintenance frequency. He concluded that, the increase in maintenance works, the increase in maintenance time\duration, and the increase in maintenance budget were the most important effects, while the lower maintenance quality was the least effect on maintenance of building . A lot of researchers explored effects of faulty design and construction on maintenance of building. Based on the reviewed literature a list of effects are summarized in Table 2.6 with list of reference. Table 2.6: Effects of faulty on maintenance and list of Reference
Increase in maintenance budget Increase in maintenance workforce Increase in maintenance works Increase in maintenance time\duration Lower maintenance quality Difficulty in maintenance planning Increased maintenance frequency Decreased building age
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(2010) De Silva & Ranainghe
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Hassanain et al ., 2013
(2012) De Silva & Ranainghe
Ali et al. (2010)
Ali (2009)
Buys &Roux(2014)
Assaf et al. (1996).
Xaba, M. I. (2012).
Lavy & Bilbo (2009)
Razak & Jaafar (2012).
Buys & Le Roux (2014)
Effects of faulty on maintenance
Hoe (2009)
Reference
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2.2.8 How to Overcome the Effect of Faulty Building Design and Construction Design plays a major role in reducing building defects. The burden goes to architects who can utilize their knowledge and expertise to reduce maintenance cost. A few important aspects that architects must consider are design, construction detail, and material selection (Kasturi, 1981). A designer must consider the implications of a complicated design.
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Holloway (1981) has an opinion similar to that of Kasturi (1981). He mentions that a designer should also consider the attitude of the users, vandalism, and the misuse of equipment, as well as the design, selection of finishes, materials, and equipment in buildings, which are all important. BRE (1991) and Richardson’s (1991) research on defects reveal the importance of weather, environmental conditions, soil impact, poor design, chemical attack, structural movement (due to poor structural design), installation method, workmanship, maintenance issues, and site working conditions. Defects could have been prevented if considerations were made on the conditions of the building elements. Razak and Jaafar (2012), studied and ranked 25 (twenty –five) strategy to overcome the effect of the faulty building design on the maintenance work in eight groups, these groups were standard of construction, professional workers, detail of construction, design team, design aspect, studies on construction, selection of materials and exterior finishes compatible with climate condition. He concluded that, the directing awareness of design team to poor design was the most important strategy, while assistance of experienced manager was least strategy to overcome the effect of the faulty building design. Hoe (2009) summarizes several recommendation and measures required to overcome the defects /errors affecting maintenance, among of them were : provide maintenance access, use suitable materials appropriate to climatic conditions, consider maintenance equipment when performing design, provide technical update to designers, increase designer field experience, improve communication with the design firm and owner and provide training to unqualified work force . Assaf et al. (1996) report that a designer should provide adequate structural design, proper access to maintenance equipment, proper exterior finishes compatible with climate conditions, and sufficient detail in construction drawings. The study concluded that most of the building maintenance problems arise from unqualified consultant staff or contractor site supervisory personal and worker. For the consultant the staff selection should be done on a systematic basis where the design engineer is tested practically and technically .
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Graham (1979) proposes solutions as cited by Razak and Jaafar (2012), that can be taken by appropriate authorities, which include directing the awareness of the design team to the consequences of poor, ill considered, and irresponsible designs; introducing critical studies on building construction, specifications, choice of materials, and maintenance characteristics into study course for the design team; enlisting the assistance of experienced maintenance managers; re-examining the methods of allocation of building work to contractors; and improving the standard of construction. De Silva and Ranasinghe (2010), studied and ranked 9 (nine) strategies to overcome maintenance problems in three groups, these group were design strategies, construction strategies, and maintenance strategies. They concluded that provide training and development programmes to improve the knowledge on building management, Involvement of a maintenance expert in the design process, allocate adequate budget for maintenance activities, having regular feedback systems, suitability for the climate (material characteristics) were the most important strategy to overcome maintenance problems . Chong and Low (2006) identified seven design strategies to overcome maintenance defects among of them were : aligning material performance against adverse weather conditions; preventing impacts from occupants and loads; preventing water leakage that cause other defects; improve specifications ; and Improve design clarity, design details, and layout. AL-Farra (2011) concluded that the importance of applying the lessons learned concept as a tool to determine the building defects and to ensure they are not repeated in future projects. 2.2.9 Previous studies Very few studies were revealed in the literature survey on the factors affecting the maintenance cost of school buildings. However, there are few studies that are related to the maintenance cost of buildings. Al-Shiha (1993) conducted a research discussing the effect of faulty design and construction factors on building maintenance. As a result, the most severe factors which affect the maintenance works and causes the high maintenance cost are determined as: inadequate structural design such as foundation, hiring unqualified designers, not
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complying with specification, not relating exterior materials selection to climate conditions, inadequate waterproofing and drainage, unqualified workplace, inability to read the dawning’s. Assaf et al. (1996) identified eleven groups of defects which are affects in building maintenance. these group were defects in civil design, architectural defects in design, design defects in maintenance practicality and adequacy, defects due to consultant firm administration and staff, defects due to construction drawing, defects due to construction inspection, defects due to civil construction, defects due to contractor administration, defects due to construction materials, defects due to construction equipment and defects due to specification. El-Haram and Horner (2002) identified 24 factors affecting housing maintenance cost and ran a survey among 50 local authority and housing association to determine the most important factors. The study concluded that high tenant expectations, budget constraints, improper use of property and right-to-buy policy were the most important factors. Al-Khatam (2003) conducted a literature review on the factors affecting the cost of maintenance in buildings. The review identified 34 factors, classified into seven major groups, namely engineering services, labor, building materials, environment, management and administration, budget and finance and building user behavior. Based on the literature review, it was concluded that the major causes for high cost of maintenance in buildings are: absence of local material standards and specifications, concern about the initial cost by owners, poor supervision and management of maintenance projects, poor scheduling, absence of standardized maintenance contracts and faulty design and construction. However, this conclusion was not supported by empirical assessment of these factors or case studies. Bin Hashem (2006) listed some factors that influence maintenance in the design stage for building maintenance such as : deterioration, future needs and faulty of choice materials. Cooper and Jones (2008) defined the key factors that contributed to high levels of dissatisfaction of the approach to maintenance programmes poor specification of initial requirements; unclear aims and objectives and inappropriate frameworks; an
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inability to predict long term cost requirements; variations in levels of experience of those conducting surveys; unrealistic claims by consultants selling survey services; inappropriate or unusable data; poor links to organizational objectives; and a lack of fit of survey data. Shah Ali (2009) conducted a survey of 200 building managers on the factors affecting the cost of building maintenance. These factors include existing building condition, building age, complaints received regarding building performance, client’s request, availability of funding, safety and health requirements. The study concluded that the cost of maintenance is affected mainly by condition of building and complaints received about building performance. (Hoe, 2009) studied 37 (thirty – seven) different defects were identified in four groups , these group were design defects, construction defects, defects due to consultant firm administration and staff, defects due to contractor administration and staff. He concluded that there are three important effects on maintenance due to the defects. These are increased maintenance works, increased maintenance time/duration and Increased maintenance budget. Shah Ali et al. (2010) identified the critical factors affecting the maintenance cost in housing projects. Totally, 31 building managers were surveyed to assess the most critical factors. The study indicated that the most important factors are expectation of tenants, building materials, building services, building age and failure to execute management at the right time. Meanwhile, it was found that two of the most influential impacts were outstanding maintenance charges and over-budget. While Cobbinah (2010) showed another type of factors as being responsible for the poor maintenance of public buildings: The age of the buildings, lack of maintenance culture, inadequate funds and high maintenance cost, pressure on building facilities by number of users and poor construction work and maintenance work done by maintenance personnel of the institution. Hassanain et al. (2013) identified and ranked 33 (thirty –three) factors affecting building maintenance cost in seven groups, these groups were: factors pertaining to the statutory requirements, factors pertaining to the design phase, factors pertaining to the construction phase, factors pertaining to the management of the maintenance
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department, factors pertaining to the budgetary estimates for maintenance activities, factors pertaining to the operations conducted by the maintenance group and factors pertaining to the community perception about the maintenance industry. Ali et al. (2013) identified types of design defects that contributed to high maintenance cost
for school building in Malaysia. These types include failure to follow well-
established design criteria in the choice of structural system and selection of materials; ignorance of the basic physical properties of the materials; use of new materials or innovative forms of construction which have not been properly tested in use; misjudgment of user and climatic conditions under which the materials have to perform; difficulty in executing the design due to impractical issues; and poor communication between members of the design and construction teams. Therefore, it is important that the earlier decisions and initiatives are taken into consideration during the design phase to ensure the proposed building design is maintenance-friendly and sustainable throughout the whole life cycle of a building. Olanrewaju and Abdul-Aziz (2015) identified the factors leading to maintenance building. These factors were: poor design, poor workmanship, defective materials and components usage and age, climatic and environmental factor, and nature of users. Also, there are few studies that are related to the defects and maintenance of buildings in Gaza city. Ziara et al. (1997) carried out a study a report which aimed to evaluate the housing conditions and affordability of households in Palestine. The findings of this report showed that more than 60% of all units were believed to be in good condition, 35% medium to bad condition, while only 3% were thought to be very bad shape. Knowing that, the used criteria in this report was not to any international standards but rather to what expected after along years of negligent and difficult economic and political circumstances. Furthermore, the report showed some important results regarding to some defects as an indicators of the deterioration in the physical condition of the housing units in Palestine. These defects focused on dampness and cracks problems. Where, the report showed that more than 60% of housing units in Gaza Strip and 30.38% of units in West Bank suffer from serious crack problem.
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Abu Hamam (2008) showed that deterioration and steel corrosion, construction errors, fire, foundation settlements, low strength concrete, effect of adjacent new constructions, water seepage and dampness, design errors and lack of maintenance are the main factors causing defects in the buildings in GS. Construction errors and design errors constituted about 27% and 3% respectively of defect causes. According to Abu Hamam (2008), buildings defects and its causes had been classified in Gaza Strip as follows: -
Defects caused by deterioration of concrete, corrosion of reinforcement or both.
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Defects in structural elements caused by other factors like cracks in slabs, columns, bearing walls, drop beams, etc.
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Defects in nonstructural elements such as craze cracks in plaster, horizontal cracks between windows concrete lintel and block works, etc.
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Other defects which occurred in building due to different causes such as dampness, inadequate compaction, or excess vibration of concrete.
AL-Farra (2011) studied and investigated the defects of the residential buildings in GS which appear mainly due to faults in design or construction phases which lead to the need for maintenance of those buildings. The survey showed that the dampness, cracks between walls and structural elements, and corrosion of reinforcement are the main defects which negatively affect the need for building maintenance. Based on his investigation improvements on tender documents were proposed in order to minimize maintenance requirements in future construction projects in Gaza. Also, the study showed the importance of applying the lessons learned concept as a tool to determine the building defects and to ensure they are not repeated in future projects. Enshassi and El- Shorafa (2015) studied the maintenance performance indicators in order to control the operation of hospital building maintenance in the Gaza Strip. Also , the survey studied the operational conditions and factors that carried out and affect the maintenance management and deriving a suitable framework for the minimum requirements. The study recommended developing a team vision for hospital maintenance department, changing the work style and culture towards maintenance, making certified periodic maintenance checklists, developing and implementing adequate key performance indicators for the Gaza strip hospital status.
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2.2.10 Summary of chapter The first part of this chapter discussed the perception of maintenance which defined maintenance as a combination of all technical and associated administrative actions intended to retain an asset in or bring it to a state in which it can perform its required function. There are six types of maintenance which may be classified into either planned maintenance or unplanned maintenance. The perspective of designer toward maintenance illustrate that design phase is very important phase to eliminate building defects that increase the cost of maintenance needed. As well as, most designers have comprehensive knowledge of building design but usually receive little or no feedback after the building is completed. Consequently, defects due to design or construction faults will be replicated in other projects. This part is adequately considered in this research. The perspective of owner toward maintenance show that owner insufficient funding of design and construction stages and the designer ignoring for the participation of the owner and the end-user in the design process will lead to maintenance problems. So the role of building owner should focus on maintenance considerations during design to maximize the value of asset and to ensure a long-term trouble-free investment. The second part of this chapter discussed the perception of building defects which defined defects as any problem that reduces the value of a home, condominium, or building. Building defects can be the result of design errors by professionals, a manufacturing flaw, defective materials, improper use or installation of materials, not conforming to the design by the contractor, or any combination of the above. Many researches and studies showed that design stage win the most important role in eliminating defects. They have, also confirmed that there are many and difference causes of building defects but poor design, workmanship, materials, and maintenance are the main causes of these defects. The ratios of defect may vary according to the different situations of these countries in terms of regulations, practices, materials, knowledge, experience, etc. The type of building defects are categorized into faulty design and faulty construction which increase the cost of maintenance and operation of the building. There are many
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factors group related of defects/errors in design stage were discussed, among of them were : defects in civil design, defects in architectural design, defects due to owner firm administration and his staff, defects due drawings, and defects due specification. Also, other factors related of defects / errors in construction stage were discussed, among of them were : defects due to lack of periodic checking and monitoring of construction, defects due contractor administration and his staff, defects due civil and architecture construction, defects due to construction equipment, and defects due to construction materials. The third part of this chapter discussed the effects of faulty design and construction to maintenance UNRWA school building projects at Gaza Strip, among of these effects were : increase in maintenance budget, increase in maintenance workforce, increase in maintenance works, increase in maintenance time\duration, lower maintenance quality. Most of previous studies and site visit focused on the technical aspects of the problem while few studies if any focused on the administrative side of the problem. So, the last part of literature review focused on the administrative side in construction projects which will be taken into account in minimization of building defects in Gaza Strip. Previous studies in Gaza Strip and out of Gaza were concerned with evaluation of the damage problems to school buildings. Maintenance aspects of the problem were not adequacy considered in the studies. In this research maintenance of the school buildings in Gaza Strip has been studied, measures on how to minimize the maintenance requirements in new school buildings and necessary recommendations and suggestions were main contribution of this research.
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3. Chapter 3: Research Methodology 3.1
Introduction
This chapter discusses the methodology which is used in this research. The methodology includes information about the research design, population, sample size, data collection, questionnaire design, questionnaire content, instrument validity, pilot study, and the method of data processing and analysis. The questionnaire will be the main approach to collect the data and perspectives of the respondents. The purpose of any research is to discover answers to questions through the application of scientific procedures. In line with this and as stated in Chapter 1, the main purpose of this research is to improve the performance of maintenance of UNRWA school buildings in GS by minimizing the defects of design and construction phase to increase the lifespan of UNRWA schools buildings. Kallet (2004) explained that, the methods section should describe what was done to answer the research question, describe how it was done, justify the experimental design, and explain how the results were analyzed. In addition, this section should describe the materials used in the study, explain how the materials were prepared for the study, describe the research protocol, explain how measurements were made and what calculations were performed, and which statistical tests were done to analyze the data.
3.2
Research Design
"Research design" refers to the plan or organization of scientific investigation. Designing a research study involves the development of a plan or strategy that will guide the collection and analyses of data (Poilt and Hungler, 1985). This research consists of eight (8) phases;
The first one is the proposal for identifying and defining the problems and establishment of the objectives of the study and development of research plan.
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The second phase of the research includes literature review. Literatures of the maintenance due to design and construction, design and construction faults/defects which affects maintenance reviewed.
The third phase of the research includes a field survey, which included UNRWA engineering department (maintenance unit, design unit, and construction units) and maintenance contractor.
The fourth phase of the research includes the questionnaire design, through distributing the pilot questionnaire to a sample of maintenance unit, maintenance contractors, consultants and design engineer. The purpose of the pilot study was to test and prove that the questionnaire questions are clear to be answered in a way that help to achieve the objectives of the study. The questionnaire was modified based on the results of the pilot study.
The fifth phase of the research was questionnaire distribution. The questionnaire was used to collect the required data in order to achieve the research objective.
The sixth phase of the research focused on data analysis and discussion. The Statistical Package for the Social Sciences (SPSS) was used to perform the required analysis.
The seventh phase of the research was interviews and case studies, which employ both quantitative and qualitative methods. In some cases personal observation or participation by the researcher was fulfilled. Other cases were based on information from interviews with project participants or through the collection of documents in the archives or records of data captured during the case study project .
The last which is the eight of the research included the conclusions, and recommendations.
Figure 3.1 illustrates the methodology flow chart, which includes the objectives of the thesis. In this research, the questionnaire approach was used to collect the factual, perceptive and attitudes of the respondents. In this research, the questionnaire approach was used as a quantitative approach to gain insights and to improve the performance of UNRWA school building maintenance in Gaza strip by minimizing the defects of design and construction phase to increase the lifespan of UNRWA schools buildings.
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According to Naoum (2007), The justification to adopt the questionnaire approach returned to the following reasons:
The questionnaire approach can be considered as an inductive approach and necessarily includes a wide range of research strategies and methods.
Topic Selection
Define the Problem
Develop Research Plan
Thesis Proposal Proposal Establish Objectives
Literature Review Review Field Surveying
Interviews experts contractors
Questionnaires Design Pilot Questionnaires
Questionnaires Validity
Results and Data Analysis
Questionnaires Reliability Conclusion and Recommendation
Case Studies Analysis
Case Studies
Questionnaires
Field Visits
Interviews
Analyze Documents and Reports
Figure 3.1: Flow Chart of Research Methodology.
From the questionnaire approach, the researcher can obtain both, qualitative data which is related to the perspectives and attitudes of the respondents in addition to the quantitative data which present the facts and actual cases in the works. Both the
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quantitative and qualitative approaches are essential to the development and continuous improvement of the construction industry.
Most of the construction management research is currently dominated by the following three principal approaches; quantitative methods, qualitative methods and mixed approach (a combination of quantitative and qualitative methods) and many researchers like Fellows and Liu (1997) explained the critical importance of the questionnaire approach in the development and collection of all necessary data for the practical and researching benefits.
Using the questionnaire approach is considered an easy, rapid and efficient approach to collect the data, facts and attitudes of the maintenance contractors, maintenance staff and designer .
The questionnaire approach is the widely used approach for descriptive and analytical surveys in order to find out the facts, opinions and views. This discussion is supported by many researchers like Fellows and Liu (1997), and Naoum (2007) . Haseman (2006) explained that, quantitative research embraces a set of scientific, deductive approaches and establishes research questions and hypotheses from theoretical models and then tests them against empirical evidence, while the qualitative research operates quite differently. It prefers inductive approaches and necessarily encompasses a wide range of research strategies and methods, and has a primary aim of understanding the meaning of human action.
3.3
Research period
The study started on September 2014, when the initial proposal was approved. The literature review was completed on the beginning of November 2014. The validity testing, piloting and questionnaire distribution and collection took two months and completed on the beginning of February 2015. Interviews and case studies, analysis, discussion, conclusion and recommendation were completed on the beginning of April 2015.
3.4
Research Population
Two populations were targeted in this research. The first population is UNRWA engineering department, which include around 80 of engineers; site/office, maintenance,
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and designers in different unit's in ICIP, among of these unit ( maintenance unit , construction unit and design unit ). These categories of staff will be considered in this study to assist in improving the maintenance performance of UNRWA school buildings in GS by minimizing the defects of design and construction phase to increase the lifespan of UNRWA schools buildings. The second population is Palestinian Contractors Union (PCU) categories that are classified under the maintenance of building categories in Gaza Strip. These categories are "1st, 2nd, and 3rd, maintenance of building categories" that have valid registration. The small categories (4th and 5th) were neglected due to the low practical and administrative experience of their companies in construction works and the low experience of their subcontractors specially in maintenance works. Based on the list of registered contractors at the PCU in December 2014, the size of population for the 1st, 2nd, 3rd, maintenance building categories was 50 companies. Most of these company have been worked with maintenance of UNRWA school buildings .
3.5
Sample size
Fellows and Liu, (1997) defined the sample as a part of total population that represents this population. Israel (2003) explained that, there are several approaches to determine the sample size. These include using a census for small populations, imitating a sample size of similar studies, using published tables, and applying formulas to calculate a sample size. Fellows and Liu, (1997) showed that, three types of sampling can be conducted during the research study; a systematic sampling, stratified sampling, and the cluster sampling. The stratified sampling will be used in this study after the sample size determination. Fellows and Liu, (1997) showed that, having determined the strata, sampling occurs most commonly by considering the relative importance of each stratum in population and using such weighting to divide this population. To determine the sample size for each population of UNRWA Engineering staff and maintenance of contractors, Kish (1965) equation was used.
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n
n' 1
n' N
n' is the sample size from infinite population, which can be calculated from this formula [n' = S²/V²]. The definitions of all variable can be defined as the following: n: sample size from finite population. N: Total population (80 UNRWA engineers and 50 maintenance contractors) V: Standard error of sample population equal 0.05 for the confidence level 95%, t = 1.96. S²: Standard error variance of population elements, S²= P (1-P); maximum at P= 0.5 The sample size for UNRWA engineering staff and maintenance contractors' population can be calculated from the previous equations as follows: n' = S²/V² = (0.5)²/(0.05)² = 100 n UNRWA engineering staff =
n maintenance contractors =
100 45 UNRWA engineering staff 1 100 / 80
100 34 maintenance contractors 1 100 / 50
Although the calculated sample size for UNRWA engineering staff is 45, the questionnaire was distributed to 60 of UNRWA engineering staff to overcome the risk of not responding from the respondents and to reflect higher reliability and benefits for the study. For the same reason, 44 questionnaires were distributed for the maintenance contractors. Fortunately, the response rate was 75% for UNRWA engineering staff and 77% for maintenance contractors as shown in Table 3.1.
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Table 3.1: Sample size and response rate of the study populations
Population Category UNRWA Eng. staff Maintenance contractors
Total Population
Calculated Sample Size
Distributed questionnaire
No of respondents
Response Rate
80
45
60
45
75%
50
34
44
34
77%
According to Moser and Kalton (1971), the obtained response rates of 75% and 77% are reasonable and will reflect good results and outputs. For the first population of UNRWA engineering staff, the selected sample represented all engineering units, which include maintenance, design and construction units. For the second population of maintenance contractors, the selected sample represented all classification categories of the maintenance contractors in GS.
3.6
Research Location
The study was carried out in Gaza Strip and targeted the UNRWA engineering department and maintenance contractors distributed all over Gaza Strip as shown in Table 3.2 below: Table 3.2: Geographical distribution of the sample.
Group
North
Gaza
Middle Area
South
Total
11
20
6
8
45
9
14
4
7
34
UNRWA Eng. staff Maintenance contractors 3.7
Data collection
The questionnaire was chosen to be the method of collecting data in this research, since the questionnaire is a fast and easy method of collecting data and is more accurate when starting processing and analyzing these data.
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3.8
Questionnaire Design
According to the literature review and after interviewing experts who are dealing with the subject at different levels, all the information that could help in achieving the study objectives were collected, reviewed and formalized to be suitable for the study survey and after many stages of brain storming, consulting, amending, and reviewing, a questionnaire was developed with closed questions. The questionnaire included one type of questions. multiple choice question. The variety in these questions aims first to meet the research objectives, and to collect all the necessary data that can support the discussion, results and recommendations in the research. The questionnaire aimed to improve the maintenance performance of UNRWA school buildings in GS by minimizing the defects of design and construction phase to increase the lifespan of UNRWA school buildings. The questionnaire comprised of four sections to accomplish the aim of the research. For each section, all related factors found in the literature and previous studies were collected and reviewed. After that, the factors were deleted, modified, merged or selected. Also, some new factors were added according to the results and recommendations of the pilot study. The following is a detailed description of the questionnaire content. 1) Section One: contained general information about the population (UNRWA Engineering staff and maintenance contractors). 2) Section Two: was about types of defects/errors in design stage affecting maintenance of UNRWA school buildings at GS. This section aimed to achieve the first and fourth objectives that intend to identify and rank the most common factors used by general. To identify the main types and causes of defects/errors in design phase that affecting maintenance of UNRWA school buildings, and to submit suggestion for solving future maintenance problem related to the school buildings at GS.
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Several previous studies were used to selected the factors in this section such as: Hoe (2009), Buys & Le Roux (2014), Razak&Jaafar (2012), Al-Shiha (1993), Al-Khatam (2003), Assaf et al. (1996), and Al-Hammad et al.(1997). Some of these studies mentioned 7 groups of factor, while 5 groups of factors were finally selected after the pilot study as shown in Table 3.3 below Table 3.3: List of defects/errors in design stage Factors from literature
Selected factors after pilot study
1. Factors related to Defects in civil /structural design Inadequate provisions for Modified Ignore design of expansion / contraction / settlement movement joint and special construction joint Ignoring aggressive environment Modified Ignore the effects of the environment and the loads on structural elements and weather conditions on the and weather condition effects materials used Added Ignoring variation in soil conditions
Modified Added
Ignoring load impact on structure stability Exceeding the allowable deflection limits Ignoring wind effects on the structure Ignoring and inadequate design for earthquakes loads effects Inadequate concrete cover on reinforcement Improperly locating conduits and pipe openings at critical structural locations
Factors related to defects in architectural design Narrow stairs, passages and doors
Modified Selected Merged
Using of type of foundations inappropriate to soil characteristics Ignore the difference in the adjacent soil layers and variation in soil conditions Ignore prepare soil tests in the projects and the depending on previous experience Ignoring the dynamic loads impact on the stability of the structural building Exceeding the allowable deflection limits Ignoring the design for wind effects and design for earthquakes loads effects on the structure
Merged Modified
Inadequate concrete cover on structural elements
Selected
Improperly locating conduits and pipe openings at critical structural locations (sleeves)
Added
Lack of attention to the design details and the concrete block walls and the intersection with the structural elements
Modified
Designing narrow stairs, passage and doors that obstruct the transfer of equipment and maintenance work process Selecting of exterior finishing material not relating to climatic condition Ignore the effect of local weather conditions at the building site for the design of the external shapes
2.
Not relating exterior material selection to climatic conditions Not considering the local climatic condition
Modified Modified
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Continue - Table 3.3: List of defects/errors in design stage Factors from literature
Selected factors after pilot study Added
Inadequate joints between finished faces
Added Modified
Architectural design not integrated with the other project drawings Unclearness of architectural detail design Designing inadequate expansions joint which don't lead to required purpose between finished faces, ceiling and wall
Added
Architectural design not integrated with the other project drawings Unclearness of architectural detail design
Modified
Inadequate (QA/QC) programs during the design
Merged
Lack of technical updating and adequate training of staff and lack of awareness of construction technology
Added
3.
Defects due to the owner administration and his staff Lack of QA/QC program during design Poor technical updating or staff training lack of awareness of construction technology
Merged Added
Lack of adequate budget for maintenance work Lack of technical background and experience of the designer Ignore the designer to the properties of materials Misjudgment of climatic conditions Lack of documentation on the maintenance work
Lack of feedback from maintenance group to The design team
Selected Selected Modified Modified
Lack of technical background and experience of the designer Ignore the designer to the properties, characteristics and behaviors of materials Misjudgment of environmental and climatic conditions
Modified
Lack of documentation and archiving of the previous maintenance
Added
Poor communication between the design team and the crew of maintenance / implementation lack of workshops to discuss construction problems between the design, supervision and implementation staff.
Modified
Added Added Factors related to defects due to drawings Lack of references Conflicts of architectural and civil drawings Lack of details
The lack of clarity and integrity and to provide full information to the designer by the owner Lack of adequate budget for maintenance work
Not be assigned to the engineer designing the parts that belonged to Staff pressure to accomplish works times less than the required period
4.
Selected Selected
Lack of references (cross sections and detailed) Conflicts of architectural and civil drawings
Modified
Poor and inaccurate details (detailed sections)
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Continue - Table 3.3: List of defects/errors in design stage Factors from literature
Selected factors after pilot study Added
Lack of auditing and archiving of approved asbuilt drawing documents electronically Dependence on repetition and lack of updating
Added 5.
Factors related to defects due to specification Unclear specification
Modified Added
Not defining adequate materials
Modified
Not specifying quality assurance & control construction procedures Not specifying to the allowable load limits Specifying inadequate concrete mix design
Selected
The specification is unclear and unrealistic lack of adequate references to clarify modern specifications Not specifying to appropriate materials and specifications Not specifying quality assurance & quality control procedures (QA/QC) Not specifying to the allowable load limits
Selected Modified
Inadequate experience and expertise to design concrete admixtures Absence of laws to building maintenance items and specifications (manual or code) Lack of local specifications and standards related of requirements of materials and workmanship
Added Added
3) Section Three: Section three : was about types of defects/errors in construction stage affecting maintenance of UNRWA school buildings at GS. This section aimed to achieve the second and fourth objectives that intend to identify and rank the most common factors used by general. To identify the main types and causes of defects/errors in construction phase that affecting maintenance of UNRWA school buildings, and to submit suggestion for solving future maintenance problem related to the school buildings at Gaza Strip. Several previous studies were used to selected the factors in this section such as : Hoe (2009), Buys & Le Roux (2014), Razak & Jaafar (2012), Al-Shiha (1993), Al-Khatam (2003), De Silva & Ranainghe (2012), De Silva & Ranainghe (2010), and Hassanain et al., 2013. The selected factors were categorized into 5 groups after the pilot study as shown in Table 3.4 below.
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Table 3.4: List of defects/errors in construction stage Factors from literature
Selected factors after pilot study
1.
Factors related to defects due to lack of inspection Lack of inspection Lack of experience and qualification of inspector Proponent (owner) negligence of the importance of inspection Weakness of inspection rule in implementing corrective actions during job execution
Modified Selected
Lack of periodic inspection and monitoring Lack of experience and qualification of inspector
Modified
Ignore of owner monitoring and checking importance Weakness of inspection rule in implementing corrective actions during construction, and not to give full powers to the inspector Insufficient testing procedures during preliminary of water feeding and sewerage networks
Modified
Added
2.
Factors related to defects due to contractor administration and his staff Non-compliance with specifications
Lack of communication between the designer and owner Lack of efficiency and expertise of contractor engineers Unable to read the drawing Speedy completion or poor quality work Unqualified work force
Selected Added
Non-compliance with specifications The contractor engineer not resident fully in the site Lack of contractor communication with the designer and owner Lack of efficiency and expertise of contractor engineers and inability to read drawing
Selected Merged Merged Modified Modified Added
Added Defects due architectural/ structural construction Inaccuracy of dimensions Poor soil compaction Excavation tools close to the building
Selected Selected Modified
Damaged Formwork
Modified
Painting in unsuitable conditions or on unsuitable surface Inadequate water proofing and drainage
Selected
Accelerate in execution to avoid delay and lack of quality Lack of workers experience and bad workmanship Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards. Contract awarding on lowest bidders price
3.
Modified
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Inaccuracy of dimensions and measurement Lake of soil compaction Excavations with mechanical excavations tools near the existing building The damage due to the multi-use of formwork In the construction industry applying of painting layers improperly Inadequate insulation against water and sanitary works
Continue - Table 3.4: List of defects/errors in construction stage Factors from literature Insufficient reinforcement concrete cover Cold joints Loss in adhesion between materials
Selected factors after pilot study
Inadequate concrete cover for reinforced concrete Modified Cold spacers between the new and old concrete Modified Weakness contiguity and coherence between materials (syrups) Early formwork removal Modified Remove formwork of concrete early before the time allowed Inadequate curing Selected Inadequate curing the casted parts well Lack of sufficient vibration Selected Lack of sufficient vibration Added Weakness and lack of homogeneity of concrete mix component or lack of compliance with the specifications components 4. Factors related to defects due to construction equipment Improper use of equipment Selected Misuse of equipment Inadequate performance of equipment Modified Inadequate quality performance and quantity of the equipment Lack of required items of equipment Modified The lack of the required spare parts elements of the equipment Added Not taking into mind the availability of the equipment used in the maintenance in the local market during implementing Added The negligence of the periodic maintenance of the equipment
Factors related defects due to construction materials Selection of material that is unsuitable for existing climatic conditions
Selected
5.
Selected
Selection of material that is unsuitable for existing climatic conditions Ignore the basic physical and chemical properties of materials The use of non-durable materials (which does not stand up) Use expired material The use of new materials are not known and did not examine the details of their quality in construction before in the local market Choice of substandard materials that have a poor quality of specifications Ignore determine the time and duration of storage and handling of materials and choosing the appropriate places Selection of cheap finishing materials price due to lack of fund
Added Use of nondurable material
Selected
Use of expired material
Selected Added
Added The use of inferior storage materials
Merged
Added
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4) Section four : Section four : was about effects of faulty design and construction to maintenance UNRWA school building projects at GS. This section aimed to achieve the third and fourth objectives that intend to identify and rank the most common factors used by general. To identify the main effects of faulty design and construction to maintenance UNRWA school building projects at GS, to submit suggestion for solving future maintenance problem related to the school buildings at GS. Several previous studies were used to select the factors in this section such as: Hoe (2009), De Silva & Ranainghe (2010 ; 2012) and Ali (2009). Eight factors were selected after the pilot study as shown in Table 3.5 below. Table 3.5: List of effects of faulty design and construction to maintenance UNRWA schools Factors from literature Increase in maintenance budget Increase in maintenance workforce Increase in maintenance works Increase in maintenance time\duration Lower maintenance quality Difficulty in maintenance planning Increased maintenance frequency Decreased building age
Selected factors after pilot study Selected Selected Selected Selected
Increase in maintenance budget Increase in maintenance workforce Increase in maintenance works
Selected Selected Selected Added
Lower maintenance quality Difficulty in maintenance planning Increased maintenance frequency Decreased building age
Increase in maintenance time\duration
The questionnaire was provided with a covering letter explaining the purpose of the study, the way of responding, the aim of the research and the security of information in order to encourage a high response. The questionnaire was distributed to UNRWA engineering staff in all units (maintenance, design and construction ) and maintenance contractors in Arabic language since the Arabic language is much effective and easier to be understood to get more realistic results. The same version questionnaire was used to collect the data and information from UNRWA engineering staff in all units and maintenance contractors. Unnecessary personal data, complex and duplicate questions were avoided. Respondents were given the choice to address their names or not. They were asked to give their opinions frankly and honestly. The final version of the questionnaire was designed in English language (attached in Annex 1), while the distributed version was
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in Arabic language (attached in Annex 2), as most members of the target population were unfamiliar with the English language.
3.9
Pilot study
It is customary practice that the survey instrument should be piloted to measure its validity and reliability and test the collected data. The pilot study provides a trial run for the questionnaire, which involves testing the wordings of questions, clarifying ambiguous questions, and testing the techniques that were used to collect data (Naoum, 2007). A pilot study for the questionnaire was conducted by distributing the prepared questionnaire to a number of experts having experience in the same field of the research to have their opinions. As shown in Table 3.6 , The piloting process was conducted through one (1) university engineer, three (3) UNRWA's` engineers, two (2) maintenance contractor's engineer, and two (2) expert consultant engineer. The two (2) maintenance contractors were selected precisely based on their technical and managerial capabilities to be sure of adding a value for the questionnaire. The three UNRWA engineers with long experience in supervising of construction and maintenance works were selected. Finally, the two consultants, university engineer, UNDP Engineer,
and Municipal’s engineer were
selected, also who have good experience in the field of supervising maintenance construction projects. Table 3.6: Profile of respondents interviewed for pilot study and content validity No 1 2 3 4 5 6 7 8 9 10
Organization University UNRWA UNRWA UNRWA UNDP Municipalities Contractor company Contractor company Consultant Consultant
Position Doctor Head of Maintenance unit Office Engineer Head of Design unit Head of construction unit Project engineer Projects manager Office Engineer Design engineer Project Manager
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Experience 20 25 20 25 20 15 10 12 20 25
The ten experts were asked to review the questionnaire and verify the validity of the questionnaire topics and its relevance to the research objective and give their advice. In general, they agreed that the questionnaire is suitable to achieve the goals of the study. Important comments and suggestions were collected and evaluated carefully. All the suggested comments and modifications were discussed with the study’s supervisor before taking them into consideration.
3.9.1 Validity of the Research Heffner (2004) explained that, validity refers to the degree in which our test or other measuring device is truly measuring what we intended it to measure. Burns and Grove (1993) defined the validity of an instrument as a determination of the extent to which the instrument actually reflects the abstract construct being examined. Polit and Hungler (1985) give another definition; "Validity refers to the degree to which an instrument measures what it is supposed to be measuring". Validity has a number of different aspects and assessment approaches. There are two ways to evaluate instrument validity: (1) content validity and (2) statistical validity, which include criterion-related validity and construct validity. (1) Content Validity of the Questionnaire
The amended questionnaire was reviewed by the supervisor and ten experts in the field of maintenance building, especially in school buildings maintenance to evaluate the procedure of questions and the method of analyzing the results. The experts agreed that the questionnaire was valid and suitable enough to measure the purpose that the questionnaire designed for. (2) Statistical Validity of the Questionnaire
Statistically, to ensure the validity of the questionnaire; Two statistical tests were applied. The first test is criterion-related validity test (Pearson test), which measures the correlation coefficient between each item in the field and the whole field. The second test is structure validity test (test) that was used to test the validity of the questionnaire structure by testing the validity of each field and the validity of the whole questionnaire.
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It measures the correlation coefficient between one field and all the fields of the questionnaire that have the same level of similar scale. A) Criterion Related Validity Internal consistency of the questionnaire was measured by a scouting sample, which consisted of ten questionnaires through measuring the correlation coefficients between each paragraph in one field and the whole field. The correlation coefficients and p-values were calculated for the paragraphs of “the factors used for defects affecting maintenance of UNRWA school buildings in design stage” and “the factors used for defects affecting maintenance of UNRWA school buildings in construction stage” It was found that the all p-values were less than 0.05 or 0.01, so the correlation coefficients were significant at α = 0.01 (p-value < 0.01) or α = 0.05 ( 0.01 < p-value < 0.05), so it can be said that these paragraphs are consistent and valid to measure what they were set for. Structure Validity of the Questionnaire Structure validity is the second statistical test that used to test the validity of the questionnaire structure by testing the validity of each field and the validity of the whole questionnaire. It measures the correlation coefficient between one field and all the fields of the questionnaire that have the same level of Lekart scale. As shown in Table 3.7, the significance values are less than 0.05 or 0.01, so the correlation coefficients of all the fields are significant at α = 0.01 (p-value < 0.01) or α = 0.05 (0.01 < p-value < 0.05), so it can be said that the fields are valid to measure what it was set for to achieve the main aim of the study. Table 3.7: Correlation coefficient between one field and all the fields No. 1 2 3
Section Factors related to defects affecting maintenance of UNRWA school buildings in design stage Factors related to defects affecting maintenance of UNRWA school buildings in construction stage Effects of faulty design and construction to maintenance of UNRWA school buildings
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Correlation
p- value
0.911
0.0001
0.830
0.0002
0.940
0.0015
3.9.2 Reliability of the Research The reliability of an instrument is the degree of consistency which measures the attribute; it is supposed to be measuring (Polit and Hunger, 1985). The less variation an instrument produces in repeated measurements of an attribute, the higher its reliability. Reliability can be equated with the stability, consistency, or dependability of a measuring tool. The test is repeated to the same sample of people on two occasions and then compares the scores obtained by computing a reliability coefficient (Polit and Hunger, 1985). It is difficult to return the scouting sample of the questionnaire-that is used to measure the questionnaire validity to the same respondents due to the different work conditions to this sample. Therefore two tests can be applied to the scouting sample in order to measure the consistency of the questionnaire. The first test is the Half Split Method and the second is Cronbach's Coefficient Alpha. A) Half Split Method This method depends on finding Pearson correlation coefficient between the means of odd questions and even questions of each field of the questionnaire. Then, correcting the Pearson correlation coefficients can be done by using Spearman Brown correlation coefficient of correction. The corrected correlation coefficient ( consistency coefficient) is computed according to the following equation : Consistency coefficient = 2r/(r+1), where r is the Pearson correlation coefficient. The normal range of corrected correlation coefficient (2r/ r+1) is between 0.0 and + 1.0 As shown in Table 3.8, all the corrected correlation coefficients values are between 0.0 and +1.0 and the significant (α ) is less than 0.01 so all the corrected correlation coefficients are significance at α = 0.01. It can be said that according to the Half Split method, the dispute causes group are reliable.
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Table 3.8: Half Split Method No.
1 2 3
Section Factors related to defects affecting maintenance of UNRWA school buildings in design stage Factors related to defects affecting maintenance of UNRWA school buildings in construction stage factors used for Effects of faulty design and construction to maintenance of UNRWA school Total
correlation
SpearmanBrown Coefficient
pvalue
0.911
0.953
0.0001
0.829
0.906
0.0002
0.942
0.970
0.0015
0.992
0.996
0.0001
B) Cronbach’s Coefficient Alpha This method is used to measure the reliability of the questionnaire between each field and the mean of the whole fields of the questionnaire. Cronbach's Alpha can be written as a function of the number of test items and the average inter-correlation among the items. Below, for conceptual purposes, we show the formula for the standardized Cronbach's alpha: α
N.c v (N - 1). c
Here N is equal to the number of items, c is the average inter-item covariance among the items and v equals the average variance. One can see from this formula that if you increase the number of items, you increase Cronbach's alpha. Additionally, if the average inter-item correlation is low, alpha will be low. As the average inter-item correlation increases, Cronbach's Alpha increases. This makes sense intuitively - if the inter-item correlations are high, and then there is evidence that the items are measuring the same underlying construct. This is really what is meant when someone says they have "high" or "good" reliability. The normal range of Cronbach’s coefficient alpha value between 0.0 and + 1.0, and the higher values reflects a higher degree of internal consistency. As shown in Table 3.9, the Cronbach’s coefficient alpha was calculated for the first field of factors used for defects affecting maintenance of UNRWA school buildings in design stage, the second field of factors used for defects affecting maintenance of UNRWA school buildings in construction stage and the third field off actors used for effects of faulty design and
86
construction to maintenance of UNRWA school buildings. The results were in the range from 1.0 and 0.960. This range is considered high; the result ensures the reliability of the questionnaire. Table 3.9: Cronbach’s Coefficient Alpha No. of Items
No. Section 1 2 3
Factors related to defects affecting maintenance of UNRWA school buildings in design stage Factors related to defects affecting maintenance of UNRWA school buildings in construction stage Factors related to effects of faulty design and construction to maintenance of UNRWA school Total
Cronbach’s coefficient alpha
41
0.960
39
0.970
8
0.880
88
0.980
Thereby, it can be said that the researcher proved that the questionnaire was valid, reliable, and ready for distribution for the sample.
3.10 Data processing and analysis The collected raw data was first sorted, edited, coded and then entered into computer software. Two programs were used, the Excel sheet and SPSS software. Appropriate graphical representations and tables were obtained to understand and analyze the questions. The ordinal scale was used in the analysis process. The ordinal scale is a ranking or rating data which normally uses integers in ascending or descending order. The relative importance index (RII) was used in the analysis in addition to other approaches such as the one way ANOVA and frequencies and percentiles. The relative index technique has been widely used in construction research for measuring attitudes with respect to surveyed variables. Several researches used the relative importance index in their analysis. Likert scaling was used for ranking questions that have an agreement levels. The respondents were asked to give their perceptions in group of questions on five-point scale (1, for the strongly disagree to 5 for the strongly agree), which reflects their assessment regarding the factors affecting bidding process. Then, the relative importance index was computed using the following equation:
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Relative Importance Index =
w 5n AN
5
4 n4 3 n3 2 n2 1 n1 5N
Where W is the weighting given to each factor by the respondent, ranging from 1 to 5, (n1 = number of respondents for strongly disagree, n2 = number of respondents for disagree, n3 = number of respondents for neutral, n4 = number of respondents for agree, n5 = number of respondents for strongly agree). "A" is the highest weight (i.e 5 in the study) and N is the total number of samples. The relative importance index ranges from 0 to 1. SPSS program was used to analyze all sections, while the MS-Excel was supportive in the presentation and layout. The analyzed data was finally presented using descriptive methods for easy interpretation and to enable comparisons.
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4.
Chapter 4: Data Analysis and Discussion
This chapter introduces the survey results and the discussion of the questionnaire's sections for UNRWA Engineering staff and Maintenance contractors. Section one presented the UNRWA Engineering staff and Maintenance contractors profile and all necessary information about the respondents. Section two in the questionnaire was designed to achieve the first and fourth objectives that intend to identify and rank the most common defects/errors factors affecting in maintenance of UNRWA school buildings at GS in design stage, and to propose recommendations to improve future maintenance for UNRWA schools in GS. Section three in the questionnaire was designed to achieve the second and fourth objectives that intended to highlight the common errors /defects factors affecting in maintenance of UNRWA schools building in construction stage at GS and to propose recommendations for solving maintenance schools problems. Section four in the questionnaire was designed to achieve the third and fourth objectives that intended to identify the effects of faulty design and construction to maintenance UNRWA school buildings at GS .
4.1
Part 1 : General Information about Respondent
This section includes eight (8) questions that ask about the type of organization, years of Experience of the organization in maintenance work, organization size(number of employees),value of projects implemented during the last five years, Position of the person filling the questionnaire, education level of the person filling the questionnaire ,Years of Experience of the person filling the questionnaire and method of gained qualification for the person filling the questionnaire.
Table 4.1: Classification of respondents Group
Frequency
Percentage
UNRWA Engineers Maintenance contractors
45
56.96 %
34
43.04%
Others
0
0%
Type of your organization
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Table 4.2: The organizations and respondent background and characteristic
UNRWA Engineers
Item
Freq.
%
maintenance contractors Freq.
%
Years of experience of the organization in maintenance work Less than 5 Years 0 0% 6 7.59% Between 5and less than10 years 6 7.59% 9 11.39% Between 10 and less than 15 years 6 7.59% 6 7.59% Between 15 and more than 15 33 41.77% 13 16.46% Organization size (number of employees) Between 1- 4 persons 0 0% 4 5.06% Between 5-20 persons 0 0% 12 15.19% Between 20 and more than 20 persons 45 56.96 % 18 22.79% Value of projects implemented during the last five years (Million Dollars) Less than 5 Millions 3 3.80% 12 15.19 % Between 5- less than 10 Millions 9 11.39% 12 15.19% Between 10- less than 15 Millions 27 34.18% 4 5.06% Between 15 and more than 15 Millions 6 7.59% 6 7.59% Position of the person filling the questionnaire Company's owner 0 0% 10 12.66% Project manager 9 11.39% 9 11.39% Site/Office engineer 15 18.99% 15 18.99% Design engineer 9 11.39% 0 0% Maintenance engineer 12 15.19% 0 0% Education level of the person filling the questionnaire Board examination exam (Tawjihi) or less 0 0% 5 6.33% Diploma 2 2.53% 5 6.33% Bachelor 28 35.44% 20 25.32% Postgraduate studies 15 18.99% 4 5.06% Years of Experience of the person filling the questionnaire Less than 3 years 6 7.59% 6 7.59% Between 3-less than 5 years 3 3.80% 6 7.59% Between 5-less than 10 years 11 13.92 10 12.66 Between 10- more than 10 years 25 31.65% 12 15.19% Gained qualification of the person filling the questionnaire from experience 32 40.51% 24 30.38% from tertiary education 6 7.59% 4 5.06% from on job training 7 8.86 6 7.59% Others 0 0% 0 0%
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All respondents Freq.
%
6 7.59 % 15 18.99 % 12 15.19 % 46 58.23% 4 12 63
5.06% 15.19% 79.75%
15 21 31 12
18.99% 26.58% 39.24% 15.19%
10 18 30 9 12
12.66% 22.78% 37.98% 11.39% 15.19%
5 7 48 19
6.33% 8.86% 60.76% 24.05%
12 15.19% 9 11.39 % 21 26.58 % 37 46.84% 56 10 13 0
70.89% 12.66% 16.45% 0%
As notice in both of Table 4.1 and Table 4.2, the Survey respondents provided a broad and representative cross-section of the key parties in construction industry projects
including UNRWA engineers, and maintenance contractors. A total of
respondents completed the questionnaire with the majority (37.98%; n = 30) drawn from Site and Office engineer. The sample population held significant positions in their organizations, and would therefore, be expected to have a good understanding of current practices and processes within their organizations and the wider construction industry. The survey participants had extensive experience in construction, and that can be observed with the years of practice they had in the industry. Table 4.2 shows that (56.96%; n=45) of all UNRWA engineers participants, and (35.44%; n=28) of maintenance contractors have more than 5 years of experience in construction maintenance. As far as education level (24.05%; n=19) of the respondents had Postgraduate degrees, with (60.76%; n= 48) of them holding a bachelor degrees It is observed that majority of the respondents worked in experienced organizations which have been a part of the Gaza’s construction sector. Which had more than 10 years' experience (31.65%; n=25) for UNRWA engineers, and (15.19%; n=12) for maintenance contractors and more than 10 million dollars of the Value of executed projects during the last five years (54.43%; n=43). These statistics indicate that the representative sample population is employed in organizations, which have been in a construction sector for a number of years and have greater chances in contribution UNRWA engineers role in construction maintenance in GS.
4.2
Part Two: Factors leading to defects/errors in design stage
This part will show the results of the responding UNRWA Engineers and maintenance contractors regarding 5 groups of factors (total 41 factors) used as follows: Group 1) Factors related to defects in civil /structural design Group 2) Factors related to defects in architectural design Group 3) Factors related to defects due to the owner administration and his staff Group 4) Factors related to defects due to drawings Group 5) Factors related to defects due to specification
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4.2.1 Factors related to defects/errors in civil /structural design Table 4.3 shows the opinion of respondents about the factors related to defects/errors in civil /structural design according to relative importance index ranked from high to low. Table 4.3: Rank and RII of factors related to defects/errors in civil /structural design UNRWA Eng.'s
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.778
1
0.743
2
0.763
1
0.739
2
0.772
1
0.753
2
0.589
3
0.500
7
0.551
3
0.439
9
0.581
4
0.500
4
0.489
5
0.500
6
0.494
5
0.378
11
0.625
3
0.484
6
0.489
4
0.434
9
0.465
7
0.483
6
0.427
10
0.459
8
0.417
10
0.507
5
0.456
9
0.456
8
0.434
8
0.446
10
0.461
7
0.272
11
0.379
11
Factors
Lack of attention to the design details and the concrete block walls and the intersection with the structural elements Improperly locating conduits and pipe openings at critical structural locations (sleeves) Ignore prepare soil tests in the projects and the depending on previous experience Ignore design of expansion / contraction / settlement joint and special construction joint Ignore the effects of the environment and the loads on structural elements and weather conditions on the materials used Inadequate concrete cover on structural elements Using of type of foundations inappropriate to soil characteristics Ignoring the dynamic loads effects on the stability of the building (elevators, air conditioners and generators) Ignoring the design for wind effects and design for earthquakes loads effects on the structure Ignore the difference in the adjacent soil layers and variation in soil conditions Exceeding the allowable deflection limits All factors
0.519
0.527
0.523
From Table 4.1, it is shown that, " Lack of attention to the design details between concrete block walls and the intersection with the structural elements " was ranked in the first position by all respondents with RII of (0.763). The responding UNRWA Eng.'s
92
ranked this factor in the first position with RII of (0.778), while the maintenance contractors ranked it in the second position with RII of (0.743). This emphasizes that, this is an important factor used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance school in design stage in this group. There is no clear referring in the design details for most UNRWA schools to leave a distance not less than 15 cm between walls and columns (Infill between columns and block), installation steel bars Φ8mm each 40cm horizontally and one steel bar Φ8mm vertically, which should be cast later with a reinforcement concrete (B200), or as the opinion of the supervising engineer. Also, the design in detail drawing ignored identifying the locations of stop beads, angel beads, movement beads and metal latching in plaster works that are required to minimize shrinkage cracks between block and concrete elements. Lack of attention to the design details between concrete block walls and the intersection with the structural elements leading to causes different type of cracks which increase maintenance work. The obtained results agreed with Al-Farra (2011). On the other hand, it is shown that, " Improperly locating conduits and pipe openings at critical structural locations (sleeves)" was ranked in the second position by all respondents with RII of (0.753). The responding UNRWA Eng.'s ranked this factor in the second position with RII of (0.739), while it was ranked in the first position by the responding maintenance contractors with RII of (0.772). This emphasizes that, this is an important factor used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance school in design stage in this group because, when the civil designer does not review the layout of the mechanical or electrical design, where the electrical or mechanical designer installs the conduits in a very critical structural area which will result in failure or continuous cracking of the structural elements or damage to the mechanical system of the building, e.g. breakage of water pipes or sewer leakage. Finally, it is shown that, " Exceeding the allowable deflection limits" was ranked in the last position by all respondents with RII of (0.379). Also, maintenance contractors in the last position with RII of (0.272),while UNRWA Eng.'s was ranked in the seventh position with RII of (0.461). Where the UNRWA design engineers aware about importance to avoid exceeds the allowable structural span length . Also, they take care when they evaluate the dead and life load to be correct. And they used drop beam as a
93
good solution to avoid any deflections. The results of this study in the first line of Razak and Jaafar (2012) who found that, this factor was in the last position in this group . Spearman rank correlation coefficient: Spearman rank correlation coefficient (Rho) is a non-parametric test for measuring the difference in ranking between target groups (UNRWA Eng.'s and maintenance contractors ). For calculation of (rho), the following simple formula is applied:
ρ 1
6 d i2 N(N 2 1)
,
(Naoum, 1998)
where, di = the difference in ranking between each pair of factors. N = number of factors. For the group of factors related to defects/errors in civil /structural design, the correlation coefficient equals to 0.694 with P-value (Sig.) = 0.000. The P-value is less than the level of significance, = 0.05, so there is a significant relationship between UNRWA Eng.'s and maintenance contractors in this group toward the opinions in this study.
4.2.2 Factors related to defects/errors in architectural design Table 4.4 was tabulated from 6 different factors related to defects/errors in architectural design. Using RII, the rank order for the most important factors from the view point of the respondents is indicated. As shown in Table 4.4 most of the respondents graded these factors from important to very important.
94
Table 4.4: Rank and RII of factors related to defects/errors in architectural design UNRWA Eng.'s
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.800
2
0.802
1
0.801
1
0.817
1
0.750
2
0.788
2
0.633
3
0.625
3
0.629
3
0.544
4
0.507
5
0.529
4
0.467
5
0.588
4
0.519
5
0.456
6
0.449
6
0.453
6
Factors
Selecting of exterior finishing and insulation material not relating to climatic condition Ignore the effect of local weather conditions at the building site for the design of the external shapes Unclearness of architectural detail design Architectural design not integrated with the other project drawings Designing inadequate expansions joint which don't lead to required purpose between finished faces ,ceiling and wall Designing narrow stairs ,passage and doors that obstruct the transfer of equipment and maintenance work process All factors
0.619
0.620
0.620
As notice in Table 4.4, it is shown that, " Selecting of exterior finishing and insulation material not relating to climatic condition (paint irresistible humidity and temperature)" was ranked in the first position by all respondents with RII of 0.801. The responding UNRWA Eng.'s ranked this factor in the second position with RII of (0.800), while the maintenance contractors ranked it in the first position with RII of (0.802).This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance school in design stage in this group. Because, the selection of color and type of exterior finish of a building should be suitable to the weather and environmental conditions. The ignoring to use special materials cannot resist heat and humidity will require a lot of cleaning and maintenance, some of examples are not painting buildings with dark colors in a dusty area where they require a lot of cleaning, or using paints which cannot resist heat and humidity, most of the design for UNRWA schools ignore environmental conditions, climate, ocean, where the finishing materials itself in schools that are located close to the sea are the same to finishing materials which is located in the center of the city, where they ignore this factor that leads to damage of finishing materials and peeled so
95
as acts outside the paint and interior, as well as there are no applying to isolate by bitumen for concrete foundation in sand or clay soil .This problem leading materials to deteriorate in shorter time and lead to defects in other parts of the building. The obtained results agreed with Assaf et al. (1996), Hoe (2009), and Razak and Jaafar (2012) who found that, this factor was in the first position in this group. Also, in the first line of Al-Hammad et al. (1997) who found that, this factor in the second position in this group from perspective of maintenance contractors. On the other hand, it is shown that, "Ignore the effect of local weather conditions at the building site for the design of the external shapes" was ranked in the second position by both UNRWA Eng.'s and maintenance contractors with RII of (0.788). The responding UNRWA Eng.'s ranked this factor in the first position with RII of (0.817) while it was ranked in the second position by the responding maintenance contractors with RII of (0.750).This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance school in design stage in this group, because the most of UNRWA schools has the same architectures design way in deferent locations and environmental conditions that related to external shape, type, and color which lead to collection of moisture, water or dust. Such design will help to increase the maintenance works like cleaning and repairing damages due to water collection on building roofs. The obtained results matching to Razak and Jaafar (2012) who found that, this factor was in the second position in this group . Finally, it is shown that, "Designing narrow stairs, passage and doors that obstruct the transfer of equipment and maintenance work process" was ranked in the last position by both of the UNRWA Eng.'s and maintenance contractors with RII of (0.453). Also, each of them separately ranked it in the last position with RII of (0.456) and (0.449) respectively. Which referring to the ignoring of respondents for this factor where they are take care in the design stage for the important of designing stairs and doors to be wide as possible and to transfer of maintenance tools easily. Anyway, in UNRWA school there is at least four stair case entrance to facility of students transfer and maintenance work easily. The obtained results agreed with Razak and Jaafar (2012) who found that, this factor was in the last position in this group.
96
Spearman rank correlation coefficient: For the group of factors related to defects/errors in architectural design, the correlation coefficient equals to 0.854 with P-value (Sig.) = 0.0005. The P-value is less than the level of significance, = 0.05, so there is a good agreement between the UNRWA Eng.'s and maintenance contractors in this group.
4.2.3 Factors related to defects/errors due to owner administration and his staff Table 4.5 shows the opinion of respondents about the factors related to defects/errors due to owner administration and his staff in design according to relative importance index ranked from high to low. Table 4.5: Rank and RII of factors related to defects/errors due to owner administration and his staff UNRWA Eng.'s
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.878
1
0.867
1
0.873
1
0.861
2
0.846
2
0.854
2
0.778
3
0.779
3
0.779
3
0.678
4
0.706
4
0.689
4
0.583
8
0.691
5
0.629
5
0.622
6
0.618
9
0.620
6
0.611
7
0.625
6
0.617
7
0.633
5
0.581
11
0.611
8
Factors
lack of workshops to discuss construction problems between the design, supervision and implementation Inadequate QA/QC programs during design stage Lack of technical updating and adequate training of staff and lack of awareness of construction technology Poor communication between the design team and the crew of maintenance / implementation Lack of documentation and archiving of the previous maintenance Lack of adequate budget for maintenance work Staff pressure to accomplish works times less than the required period The lack of clarity and integrity and to provide full information to the designer by the owner
97
Continue - Table 4.5: Rank and RII of factors related to defects/errors due to owner administration and his staff UNRWA Eng.'s
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.556
10
0.625
7
0.585
9
0.567
9
0.588
10
0.576
10
0.506
11
0.618
8
0.554
11
0.489
12
0.567
12
0.522
12
Factors
Lack of technical background and experience of the designer Misjudgment of environmental and climatic conditions Not be assigned to the engineer designing the parts that belonged to Ignore the designer to the properties, characteristics and behaviors of materials All factors
0.647
0.676
0.659
As notice in Table 4.5, it is shown that, " lack of workshops to discuss construction problems between the design, supervision and implementation" was ranked in the first position by all respondents with RII of (0.873). Also, each of them separately ranked it in the first position with RII of (0.878) and (0.867) respectively. This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors owner administration and his staff during design stage. Communication between the maintenance and design groups is important to get the views of the maintenance staff on issues related the selection of material, systems and equipment. Lack of communication would result in the repetition of faulty design, which affects the cost of maintenance. The obtained results agreed with Hassanain et al. (2013), who emphasized that this factor is an important factor that in the group related to defects due owner administration and his staff. On the other hand, it is shown that, " Inadequate QA/QC programs during the design stage " was ranked in the second position by all respondents with RII of (0.854). Also, each of them separately ranked it in the second position with RII of (0.861) and (0.846) respectively. This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors owner administration and his staff during design stage, where that the implementation for quality assurance and quality
98
control programs on design is very important to reduce the number of defects and mistakes in design. This procedure requests one group to do the design and another group to review and highlight the design defects. The obtained results agreed with Assaf et al. (1996), Razak and jaafar (2012) who found that, this factor was in the second position in this group. "Lack of technical updating and adequate training of staff and lack of awareness of construction technology" was ranked in the third position by all respondents with RII of (0.779). Also, each of them separately ranked it in the third position with RII of (0.778) and (0.779) respectively. This referring to the important of owners in update and expose their staff to the latest construction material and methods in the market. In addition, they should maintain and keep track of the new materials redundant or construction methods and make sure that they perform adequately in the existing building environment. All UNRWA schools till now not used the technology and modern finishing materials in schools as examples, in new covering materials like acoustic texture exterior paint (popcorn Gargamish paint), that are resistant to dampness and bad weather. The obtained results agreed with Razak and jaafar (2012) who found that, this factor was in the second position in this group. Finally, it is shown that, "Not be assigned to the engineer designing the parts that belonged to" was ranked in the last position by both of the UNRWA Eng.'s and maintenance contractors with RII of (0.522). Also, each of them separately ranked it in the last position with RII of (0.861) and (0.846) respectively because , there are many numbers of specialist engineers in design unit, where every engineer responsible for his specialization. Spearman rank correlation coefficient: For the group of factors related to defects/errors due to owner administration and his staff in design stage, the correlation coefficient equals to 0.929 with P-value (Sig.) = 0.0007. The P-value is less than the level of significance, = 0.05, so there is a total agreement between UNRWA Eng.'s and maintenance contractors in this group.
99
4.2.4 Factors related to defects/errors due to drawing Table 4.6 was tabulated from 5 different factors related to defects/errors due to drawing in design stage. Using RII, the rank order for the most important factors from the view point of the respondents is indicated. As shown in Table 4.6 most of the respondents graded these factors from important to very important Table 4.6: Rank and RII of factors related to defects/errors due to drawing UNRWA Eng.'s
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.811
2
0.860
1
0.832
1
0.839
1
0.816
2
0.829
2
0.656
3
0.699
3
0.674
3
0.639
4
0.691
4
0.661
4
0.567
5
0.478
5
0.529
5
Factors
Lack of auditing and archiving of approved as-built drawing documents electronically Dependence on repetition and lack of updating Poor and inaccurate details (detailed sections) Conflicts of architectural and civil drawings Lack of references (cross sections and detailed) All factors
0.702
0.709
0.705
As notice in Table 4.6, it is shown that, " Lack of auditing and archiving of approved asbuilt drawing documents electronically " was ranked in the first position by all respondents with RII of (0.832). Also, in the first position by maintenance contractors with RII of (0.860). While, in the second position by UNRWA Eng.'s with RII of (0.811). Which means the importance of as built drawing where, the construction contractors sometime do not provide accurate as-built drawings to the owner after completed the works. Such drawings are used by the maintenance contractor discrepancies between actual conditions and conditions reflected in the as-built drawings would draw the maintenance contractor to wrong assumptions. On the other hand, it is shown that, Dependence on repetition and lack of updating " was ranked in the second position by both UNRWA Eng.'s and maintenance contractors with RII of (0.829). Also, in the second position by maintenance contractors with RII of (0.816), while , in the first position by UNRWA Eng.'s with RII of (0.839). This emphasizes that, this is the most important factor used by UNRWA Eng.'s and
100
maintenance contractors related to defects/errors due to drawing in design stage. The wrong sections and not update lead to repeat the same mistake and repeat the same works that you need to remove and increase the cost and time to repeat. Finally, it is shown that, " Lack of references such as cross sections and detailed " was ranked in the last position by all respondents with RII of (0.529). Each of them separately ranked it in the last position with RII of (0.567) and (0.478) respectively. Which means most of UNRWA school buildings design drawings were show the cross section and detailed references clearly on the drawing. Also, the designer not allow to the contractors to construct the building according to his understanding and experience to avoid defects and errors which lead to increasing of maintenance work. Spearman rank correlation coefficient: For the group of factors related to defects/errors due to drawing in design stage, the correlation coefficient equals to 0.920 with P-value (Sig.) = 0.0012. The P-value is less than the level of significance, = 0.05, so there is a total agreement between the UNRWA Eng.'s and maintenance contractors in this group.
4.2.5 Factors related to defects/errors due to specification Table 4.7 shows the opinion of respondents about the factors related to defects/errors due to specification in design stage according to relative importance index ranked from high to low. Table 4.7: Rank and RII of factors related to defects/errors due to specification UNRWA Eng.'s
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.789
2
0.816
1
0.801
1
0.794
1
0.779
2
0.788
2
0.628
3
0.691
4
0.655
3
Factors
Not specifying quality assurance &control procedures (QA/QC) Lack of local specifications and standards related of requirements of materials and workmanship The specification is unclear and unrealistic
101
Continue - Table 4.7: Rank and RII of factors related to defects/errors due to specification UNRWA Eng.'s
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.500
5
0.706
3
0.589
4
0.517
4
0.581
5
0.544
5
0.417
6
0.419
6
0.418
6
0.367
7
0.309
7
0.342
7
Factors
Absence of laws to building maintenance items and specifications (manual or code) Not specifying to appropriate materials and specifications Not specifying to the allowable load limits Inadequate experience and expertise to design concrete admixtures All factors
0.573
0.615
0.591
Table 4.7 shows that the all respondents ranked " Not specifying quality assurance & control procedures " in the first position with RII of (0.801). The responding UNRWA Eng.'s ranked this factor in the second position with RII of (0.789), while the maintenance contractors ranked it in the first position with RII of (0.816). This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors due specification in design stage. This means the old specification in UNRWA schools building do not specify the relation between owner, the inspector and contractor, and how to communicate properly to avoid any defect or solve any problem. Also, not specify the responsibility of each party, but I think in the updated specifications, there are referring to this issues and identify the responsibilities for the entire party. The obtained results agreed with Razak and jaafar (2012) who found that, this factor was in the second position in this group. On the other hand, it is shown that, " Lack of local specifications and standards related of requirements of materials and workmanship " was ranked in the second position by all respondents with RII of (0.788). The responding UNRWA Eng.'s ranked this factor in the first position with RII of (0.794), while the maintenance contractors ranked it in the second position with RII of (0.779). This means the important of standard and specification documents to building maintenance, as it constitutes a schedule of instructions to contractor and workmanship requirement .
102
Finally, it is shown that, " Inadequate experience and expertise to design concrete admixtures" was ranked in the last position by all respondents with RII of (0.342). Each of them separately ranked it in the last position with RII of (0.367) and (0.309) respectively. Which means ignoring this factors by all respondents, where the UNRWA design section have a designers, which design the concrete mix to meet the strength requirements and the equality and durability side . Spearman rank correlation coefficient: For the group of factors related to defects/errors due to drawing in design stage, the correlation coefficient equals to 0.777 with P-value (Sig.) = 0.0001. The P-value is less than the level of significance, = 0.05, so there is a good agreement between the UNRWA Eng.'s and maintenance contractors in this group.
4.2.6 Comparison between all groups of factors leading to errors/defects in design stage . Table 4.8 shows the opinions of the respondents about the groups of factors leading to errors/defects in design stage according to relative index from high to low. Table 4.8: Rank and RII group of factors related to defects/errors in design stage UNRWA Eng.'s
maintenance contractors
RII
Rank
RII
Rank
RII
Rank
0702
1
0.709
1
0.705
1
0.647
2
0.676
2
0.659
2
0.619
3
0.620
3
0.620
3
0.573
4
0.615
4
0.591
4
0.519
5
0.527
5
0.523
5
All respondents
Factors
factors related to defects/errors due to drawing factors related to defects/errors due to owner administration and his staff factors related to defects/errors in architecture design factors related to defects/errors due to specification factors related to defects/errors in civil/ structural design All factors
0.603
0.621
0.605
From Table 4.8, it is shown that, " factors related to defects/errors due to drawing " was ranked in the first position by all respondent's with RII of (0.705). Each of them
103
separately ranked it in the first position with RII of (0.702) and (0.709) respectively. This emphasizes that, this is the most important group used by both the UNRWA Eng.'s and maintenance contractors which affecting maintenance of UNRWA schools building in design stage. Because, lack of references, cross sections and details of structural elements will lead the contractor to construct the building according to his understanding and experiences, which cause many maintenance defects which can only be discovered during building operation. On the other hand, it is shown that, " factors related to defects/errors due to owner administration and his staff " was ranked in the second position by all respondents with RII of (0.659). Each of them separately ranked it in the second position with RII of (0.647) and (0.676) respectively. This emphasizes that, this is the most important group used by both the UNRWA Eng.'s and maintenance contractors which affecting maintenance of UNRWA schools building in design stage. Because the experiences of owners and his staff which play big role in maintenance works to avoid a lot of maintenance defects. This referring to the importance of owner role in minimizing of defects through identifying type of errors, causes, and proposed prevention methods to minimize it appearance in future projects. Finally, it is shown that, " factors related to defects/errors in civil/ structural design " was ranked in the last position by both of the UNRWA Eng.'s and maintenance contractors with RII of (0.523). Each of them separately ranked it in the last position with RII of (0.519) and (0.527) respectively. This means the ignoring of responding to this factor, where there is a big design unit in ICIP at UNRWA, which have a number of experts and trained staff in all specialties of construction. Spearman rank correlation coefficient: For the group of factors related to groups factors leading to defects / errors in design stage, the correlation coefficient equals to 0.953 with P-value (Sig.) = 0.0001. The Pvalue is less than the level of significance, = 0.05, so there is a total agreement between the UNRWA Eng.'s and maintenance contractors in this group.
104
4.2.7 Ranking and RII of all factors leading to defect/error in design stage Table 4.9 was tabulated from 41 different factors leading to the defects/errors in design stage. Using RII, the rank order for the most important factors from the view point of the respondents is indicated. As shown in Table 4.9 most of the respondents graded these factors from important to very important. Table 4.9: Ranking and RII of all factors leading to errors/defects in design stage UNRWA Eng.'s
Factors lack of workshops to discuss construction problems between the design, supervision and implementation Inadequate ( QA/QC) programs during design stage Lack of auditing and archiving of approved as-built drawing documents electronically Dependence on repetition and lack of updating Selecting of exterior finishing material not relating to climatic condition Not specifying quality assurance &control procedures(QA/QC) Ignore the effect of local weather conditions at the building site for the design of the external shapes Lack of local specifications and standards related of requirements of materials and workmanship Lack of technical updating and adequate training of staff and lack of awareness of construction technology Lack of attention to the design details and the concrete block walls and the intersection with the structural elements Improperly locating conduits and pipe openings at critical structural locations (sleeves) Poor communication between the design team and the crew of maintenance / implementation Poor and inaccurate details (detailed sections) Conflicts of architectural and civil drawings
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.878
1
0.868
1
0.873
1
Owner administration
0.861
2
0.846
3
0.854
2
Owner administration
0.811
5
0.860
2
0.832
3
drawing
0.839
3
0.816
4
0.829
4
drawing
0.800
6
0.802
6
0.801
5
Architecture design
0.789
8
0.816
5
0.801
6
Specification
0.817
4
0.750
10
0.788
7
Architecture design
0.794
7
0.779
7
0.788
8
Specification
0.778
9
0.779
8
0.779
9
Owner administration
0.778
10
0.743
11
0.763
10
Civil/ Structural design
0.739
11
0.772
9
0.753
11
Civil/ Structural design
0.678
12
0.706
12
0.689
12
Owner administration
0.656
13
0.699
14
0.674
13
drawing
0.639
14
0.691
17
0.661
14
drawing
105
Group
Continue - Table 4.9: Ranking and RII of all factors leading to errors/defects in design stage UNRWA Eng.'s
maintenance contractors
All respondents
Factors
RII
Rank
RII
Rank
RII
Rank
The specification is unclear and unrealistic Lack of documentation and archiving of the previous maintenance
0.628
17
0.691
16
0.655
15
0.583
21
0.691
15
0.629
16
unclearness of architectural detail design
0.633
16
0.625
20
0.629
17
0.622
18
0.618
23
0.620
18
0.611
19
0.625
18
0.617
19
0.633
15
0.581
26
0.611
20
0.500
28
0.706
13
0.589
21
0.556
24
0.625
19
0.585
22
0.567
22
0.588
24
0.576
23
0.506
27
0.618
22
0.554
24
0.589
20
0.500
33
0.551
25
0.517
26
0.581
27
0.544
26
Specification
0.544
25
0.507
30
0.529
27
Architecture design
0.567
23
0.478
34
0.529
28
drawing
0.489
29
0.566
29
0.522
29
Owner administration
0.467
33
0.588
25
0.519
30
Architecture design
0.439
37
0.581
28
0.500
31
Civil/ Structural design
0.489
31
0.500
32
0.494
32
Civil/ Structural design
0.378
40
0.625
21
0.484
33
0.489
30
0.434
37
0.465
34
0.483
32
0.427
38
0.459
35
0.417
39
0.507
31
0.456
36
Lack of adequate budget for maintenance work Staff pressure to accomplish works times less than the required period The lack of clarity and provide full information to the designer by the owner Absence of laws to building maintenance items and specifications (manual or code) Lack of technical background and experience of the designer Misjudgment of environmental and climatic conditions Not be assigned to the engineer designing the parts that belonged to Ignore prepare soil tests in the projects and the depending on previous experience Not specifying to appropriate materials and specifications Architectural design not integrated with the other project drawings Lack of references (cross sections and detailed) Ignore the designer to the properties, characteristics and behaviors of materials Designing inadequate expansions joint which don't lead to required purpose between finished faces ,ceiling and wall Ignore design of expansion / contraction / settlement joint and special construction joint Ignore the effects of the environment and the loads on structural elements and weather conditions on the materials used Inadequate concrete cover on structural elements Using of type of foundations inappropriate to soil characteristics Ignoring the dynamic loads impact on the stability of the structural building Ignoring the design for wind effects and design for earthquakes loads effects on the structure
106
Group Specification Owner administration Architecture design Owner administration Owner administration Owner administration Specification Owner administration Owner administration Owner administration Civil/ Structural design
Civil/ Structural design Civil/ Structural design Civil/ Structural design Civil/ Structural design
Continue - Table 4.9: Ranking and RII of all factors leading to errors/defects in design stage UNRWA Eng.'s
Factors
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.456
35
0.449
35
0.453
37
0.456
36
0.434
36
0.446
38
0.417
38
0.419
39
0.418
39
Exceeding the allowable deflection limits
0.461
34
0.272
41
0.379
40
Inadequate experience and expertise to design concrete admixtures
0.367
41
0.309
40
0.342
41
Designing narrow stairs ,passage and doors that obstruct the transfer of equipment and maintenance work process Ignore the difference in the adjacent soil layers and variation in soil conditions Not specifying to the allowable load limits
Group Architecture design Civil/ Structural design Specification Civil/ Structural design Specification
Spearman rank correlation coefficient: For the group of factors related to errors/defects in design stag, the correlation coefficient equals to 0.953 with P-value = 0.0001. The P-value is less than the level of significance, = 0.05, so there is a total agreement between the UNRWA Eng.'s and maintenance contractors. Other descriptive statistics for the factors related to defects/errors in design stage attached in the tables from (1 to 5) at Annex 3.
4.2.8 Top ten factors leading to the errors/defects in design stage Table 4.10 was tabulated from ten (10) factors leading to the errors/defects which affecting maintenance of UNRWA schools buildings in design stage ranked from high to low. Table 4.10: Top ten factors leading to errors/defects in design stage All respondents
The factors
RII
lack of workshops to discuss construction problems between the design, supervision and implementation
Rank
107
Owner administratio n Owner administratio n
0.873
1
0.854
2
0.832
3
drawing
0.829
4
drawing
Inadequate ( QA/QC) programs during design stage Lack of auditing and archiving of approved as-built drawing documents electronically Dependence on repetition and lack of updating
Group
Continue - Table 4.10: Top ten factors leading to errors/defects in design stage All respondents
The factors
RII
Selecting of exterior finishing and isolation material not relating to climatic condition Not specifying quality assurance &control (QA/QC) procedures Ignore the effect of local weather conditions at the building site for the design of the external shapes Lack of local specifications and standards related of requirements of materials and workmanship Lack of technical updating and adequate training of staff and lack of awareness of construction technology Lack of attention to the design details and the concrete block walls and the intersection with the structural elements
Rank
Group
0.801
5
Architecture design
0.801
6
Specification
0.788
7
Architecture design
0.788
8
Specification
0.779
9
Owner administration
0.763
10
Civil/ Structural design
From Table 4.10, it is shown that " lack of workshops to discuss construction problems between the design, supervision and implementation" related to factors leading to defects/errors due to owner administration and his staff group in design stage was ranked in the first position by all respondents with RII of (0.873). This emphasizes that, this is the most important factor used by all respondents related to defects/errors owner administration and his staff during design stage. Communication between the maintenance and design groups is important to get the views of the maintenance staff on issues related the selection of material, systems and equipment. Lack of communication would result in the repetition of faulty design, which affects the cost of maintenance. The obtained results agreed with Hassanain et al. (2013), who emphasized that this factor is an important factor that in the group related to defects due owner administration and his staff. " Inadequate ( QA/QC) programs during design stage " which related to factors leading to defects/errors due to owner administration and his staff group in design stage was ranked in the second position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.854). This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors owner administration and his staff during design stage, where that the implementation for quality assurance and quality control programs on design is very important to reduce the
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number of defects and mistakes in design. This procedure requests one group to do the design and another group to review and highlight the design defects. The obtained results agreed with Assaf et al. (1996), Razak and jaafar (2012) who found that, this factor was in the second position in this group. " Lack of auditing and archiving of approved as-built drawing documents electronically" which related to factors leading to defects/errors due to drawing group in design stage was ranked in the third position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.832). The Construction contractors sometime do not provide accurate as-built drawings to the owner. Such drawings are used by the maintenance contractor discrepancies between actual conditions and conditions reflected in the as-built drawings would draw the maintenance contractor to wrong assumptions. " Dependence on repetition and lack of updating " which related to factors leading to defects/errors due to drawing group in design stage was ranked in the fourth position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.829).This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors due to drawing in design stage. The wrong sections and not update lead to repeat the same mistake and repeat the same works that you need to remove and increase the cost and time to repeat. " Selecting of exterior finishing and isolation material not relating to climatic condition " which related to factors leading to defects/errors due to architecture design group in design stage was ranked in the fifth position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.801). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance schools in design stage in this group, because the selection of color and type of exterior finish of a building should be suitable to the weather and environmental conditions. The ignoring to use special materials cannot resist heat and humidity will require a lot of cleaning and maintenance, some of examples are not painting buildings with dark colors in a dusty area where they require a lot of cleaning, or using paints which cannot resist heat and
109
humidity, most of the design for UNRWA schools ignore environmental conditions, climate, ocean, where the finishing materials itself in schools that are located close to the sea are the same to finishing materials which is located in the center of the city, where they ignore this factor that leads to damage of finishing materials and peeled so as acts outside the paint and interior, as well as there are no applying to isolate by bitumen for concrete foundation in sand or clay soil. This problem leading materials to deteriorate in shorter time and lead to defects in other parts of the building. The obtained results agreed with Assaf et al. (1996), Hoe (2009), and Razak and Jaafar (2012) who found that, this factor was in the first position in this group. Also, in the first line of Al-Hammad et al. (1997) who found that ,this factor in the second position in this group from perspective of maintenance contractors. " Not specifying quality assurance & control procedures)" which related to factors leading to defects/errors due to specification group in design stage was ranked also in the sixth position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.801). This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors due specification in design stage. This means the old specification in UNRWA schools building do not specify the relation between owner, the inspector and contractor, and how to communicate properly to avoid any defect or solve any problem. Also, not specify the responsibility of each party, but I think in the updated specifications there are referring to this issues and identify the responsibilities for the entire party. The obtained results agreed with Razak and jaafar (2012) who found that, this factor was in the second position in this group. " Ignore the effect of local weather conditions at the building site for the design of the external shapes " which related to factors leading to defects/errors due to architecture design group in design stage was ranked in the seventh position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.788). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance school in design stage in this, because
the most of UNRWA schools has the same architectures design way in
deferent locations and environmental conditions that related to external shape, type, and color which lead to collection of moisture, water or dust. Such design will help to
110
increase the maintenance works like cleaning and repairing damages due to water collection on building roofs. The obtained results matching to Razak and Jaafar (2012) who found that, this factor was in the second position in this group . " Lack of local specifications and standards related of requirements of materials and workmanship " which related to factors leading to defects/errors due to specification group in design stage was ranked also in the eighth position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.788). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance. This means the important of standard and specification documents to building maintenance, as it constitutes a schedule of instructions to contractor and workmanship requirement . " Lack of technical updating and adequate training of staff and lack of awareness of construction
technology subcontractors)"which
related
to
factors
leading
to
defects/errors due to owner administration and his staff group in design stage was ranked in the ninth position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.779). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance. This referring to the important of owners in update and expose their staff to the latest construction material and methods in the market. In addition, they should maintain and keep track of the new materials redundant or construction methods and make sure that they perform adequately in the existing building environment. All UNRWA schools till now not used the technology in schools as examples in new covering materials like acoustic texture exterior paint (popcorn Gargamish paint) . The obtained results agreed with Razak and jaafar (2012) who found that, this factor was in the second position in the group of factors leading to errors/defects in design . " Lack of attention to the design details and the concrete block walls and the intersection with the structural elements " which related to factors leading to defects/errors due to civil/ structural design group in design stage was ranked in the tenth position by both the UNRWA Eng.'s and maintenance contractors with RII of (0.763).This emphasizes that, this is an important factor used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance school in design stage in this group, There is no
111
clear referring in the design details for most UNRWA schools to leave a distance not less than 15 cm between walls and columns (Infill between columns and block), installation steel bars Φ8mm each 40cm horizontally and one steel bar Φ8mm vertically, which should be cast later with a reinforcement concrete (B200), or as the opinion of the supervising engineer. Also, the design in detail drawing ignored identifying the locations of stop beads, angel beads, movement beads and metal latching in plaster works that are required to minimize shrinkage cracks between block and concrete elements. Lack of attention to the design details between concrete block walls and the intersection with the structural elements leading to causes different type of cracks which increase maintenance work. The obtained results agreed with Al-Farra (2011), who emphasized that this factor is an important factor that in the group related to defects due to civil design .
4.3 Part Three : Factors leading to defects/errors in construction stage This part will show the results of the responding UNRWA Engineers and maintenance contractors regarding 5 groups of factors (total 39 factors) used as follows: Group 1) Factors related to defects due to lack of inspection. Group 2) Factors related to defects due contractor administration and his staff Group 3) Factors related to defects due to due architectural /structural construction Group 4) Factors related to defects construction equipment Group 5) Factors related to defects due to construction material
4.3.1 Factors related to defects/errors due to lack of inspection Table 4.11 shows the opinion of respondents about the factors related to defects/errors due to lack of inspection in construction stage according to relative importance index ranked from high to low.
112
Table 4.11: Rank and RII of factors related to defects due to lack of inspection
Factors
UNRWA Eng.'s RII
Insufficient testing procedures during preliminary of water feeding and sewerage Lack of periodic inspection and monitoring Ignore of owner monitoring and checking importance Lack of experience and qualification of inspector Weakness of inspection rule in implementing corrective actions . All factors
Rank
maintenance contractors RII Rank
All respondents RII
Rank
0.861
1
0.831
2
0.848
1
0.833
2
0.846
1
0.839
2
0.772
3
0.669
3
0.728
3
0.533
4
0.662
4
0.589
4
0.528
5
0.581
5
0.551
5
0.706
0.717
0.711
As notice in Table 4.11, it is shown that, " Insufficient testing procedures during preliminary of water feeding and sewerage networks " was ranked in the first position by all respondents with RII of (0.848). The responding UNRWA Eng.'s ranked this factor in the first position with RII of (0.861), while the maintenance contractors ranked it in the second position with RII of (0.831). This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors due to lack inspection during construction stage. Poor supervision which is represented by insufficiency in conducting the required tests for plumbing, and sanitary works and poor workmanship which is represented in poor treatment or insulation of underground galvanized water supply system were the main causes of pipe and waterproofing defects. Many supervisors don't give the required importance to conduct the necessary tests and inspections for plumbing works. Undoubtedly, implementation of periodic inspection for the plumbing works for each school buildings will show any leaks in plumbing pipes during construction phase. This underlines the role of supervision in minimizing the emergence of such defects in the school buildings. So, all plumping and sanitary works should be carried out under supervision of a mechanical engineer with experience not less than five years, and the contractor should carry out all the required tests to prevent any leaks in the water supply system and plumping works firstly for every floor separately and after this for all floors in the same time. Among of these tests were : pressure tests and hydrostatic pressures. The obtained results agreed with Al-Farra (2011), who emphasized that this factor is an important
113
factor that in the group related to defects due to lack of periodic checking and monitoring. On the other hand, it is shown that, " Lack of periodic inspection and monitoring" was ranked in the second position by all respondents with RII of (0.839). The responding UNRWA Eng.'s ranked this factor in the second position with RII of (0.833), while the maintenance contractors ranked it in the first position with RII of (0.846). This means the importance of this factor where, there is inspection practice in UNRWA school buildings but not periodic, if the periodic inspection increases, quality increases. Therefore , the maintenance needed is reduce . Obtained results agreed with Assaf et al.(1996) and Buys & Roux (2014) who emphasized that this factor is an important factor that in the group related to lack of inspection from the viewpoint of the maintenance contractor. Finally, it is shown that, " Weakness of inspection rule in implementing corrective actions during construction and not to give full powers to the inspector " was ranked in the last position by all respondents with RII of (0.551). Each of them separately ranked it in the last position with RII of (0.528) and (0.581) respectively. This means ignoring this factor by respondents because, there is no channel between UNRWA Eng.'s and contractors maintenance, where is the resident engineer has the full power in the site. This cause avoid of delays and any corrective action comes late, after the elements are already constructed with poor quality . Spearman rank correlation coefficient: For the group of factors related to defects/errors due to lack of periodic checking and monitoring of construction in construction stage, the correlation coefficient equals to 0. 67 with P-value (Sig.) = 0.0017. The P-value is less than the level of significance, = 0.05, so there is a significant relationship between the UNRWA Eng.'s and maintenance contractors in this group.
114
4.3.2 Factors related to defects/errors due to contractor administration and his staff Table 4.12 shows the opinion of respondents about the factors related to defects/errors due to contractor administration and his staff in construction stage according to relative importance index ranked from high to low. Table 4.12: Rank and RII of factors related to defects due to contractor administration and his staff
Factors contract awarding on lowest bidders price Accelerate in execution to avoid delay and lack of quality Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards. Lake of workers experience and bad workmanship Lack of efficiency and expertise of contractor engineers Non-compliance with specifications The contractor engineer not resident fully in the site Lack of communication between the designer and owner All factors
UNRWA Eng.'s
maintenance contractors RII Rank
RII
Rank
0.906
1
0.882
0.850
2
0.700
All respondents RII
Rank
1
0.896
1
0.846
2
0.848
2
3
0.831
3
0.756
3
0.678
4
0.588
7
0.639
4
0.656
5
0.574
8
0.620
5
0.617
6
0.618
6
0.617
6
0.572
7
0.662
4
0.611
7
0.528
8
0.632
5
0.573
8
0.688
0.704
0.695
" contract awarding on lowest bidders price " was ranked as the first factor considered by all respondents with RII of (0.896). Each of them separately ranked it in the first position with RII of (0.906) and (0.882) respectively. This emphasizes that, this is the most important factor used by UNRWA Eng.'s and maintenance contractors related to defects/errors due to contractor administration and his staff in construction stage. This due to UNRWA awarding the projects depend on the low price of the contractor. The method of awarding maintenance contracts play a big role in defects to contractor administration and his staff in construction stage. When public maintenance contracts are awarded based on competitive bidding, with the selection of the lowest bidder, The least bidder will try to complete the work with the lowest bidder. This affects the quality of the works.
115
On the other hand, it is shown that, " Accelerate in execution to avoid delay and lack of quality" was ranked in the second position by all respondents with RII of (0.848). The responding UNRWA Eng.'s ranked this factor in the second position with RII of (0.850) , while the maintenance contractors ranked it in the second position with RII of (0.846). This means the maintenance contractors tend to do the job which needs tools or equipment quickly to reduce rental time. In addition they always tend to select cheap quality materials to save money. Finally, it is shown that, " Lack of communication between the designer and owner" was ranked in the last position by all respondents with RII of (0.573). Also, the responding UNRWA Eng.'s ranked this factor in the last with RII of (0.528), while the responding maintenance contractors in the fifth position with RII of (0.632). This means there is a good communication between maintenance contractors and UNRWA Eng.'s (design and maintenance engineers ) for understanding of specification and consultation, where the dependency on experience alone cause a lot of maintenance defects. The obtained results disagreed with Hoe (2009) who found that, this factor was in the first position in this group. Spearman rank correlation coefficient: For the group of factors related to defects/errors due to contractor administration and his staff in construction stage, the correlation coefficient equals to 0.973 with P-value (Sig.) = 0.0008. The P-value is less than the level of significance, = 0.05, so there is a total agreement between the UNRWA Eng.'s and maintenance contractors in this group.
4.3.3 Factors related to defects/errors due to architectural and structural construction Table 4.13 shows the opinion of respondents about the factors related to defects/errors due to architectural and structural construction in construction stage according to relative importance index ranked from high to low.
116
Table 4.13: Rank and RII of factors related to defects due architectural /structural construction
Factors The damage due to the multi-use of formwork in the construction industry implementation of internal and external paint improperly Inadequate insulation against water and sanitary works Inadequate curing the casted parts well Weakness and lack of homogeneity of concrete mix component or lack of compliance with the specifications components Remove framework of concrete early before the allowed time Lack of sufficient vibration Weakness contiguity and coherence between materials (syrups) Excavations with mechanical excavations tools near the existing building Inadequate concrete cover for reinforced concrete Lake of soil compaction Cold spacers between the new and old concrete Inaccuracy of dimensions and measurement All factors
UNRWA Eng.'s
maintenance contractors RII Rank
RII
Rank
0.839
1
0.889
0.833
2
0.689
All respondents RII
Rank
1
0.861
1
0.846
2
0.839
2
3
0.735
3
0.709
3
0.550
5
0.647
4
0.592
4
0.539
6
0.639
5
0.582
5
0.567
4
0.581
8
0.573
6
0.522
7
0.581
7
0.548
7
0.489
9
0.581
9
0.529
8
0.467
12
0.603
6
0.525
9
0.500
8
0.552
12
0.522
10
0.483
11
0.566
10
0.519
11
0.483
10
0.559
11
0.516
12
0.450
13
0.463
13
0.456
13
0.570
0.634
0.598
As notice in Table 4.13, it is shown that, " The damage due to the multi-use of formwork in the construction industry " was ranked in the first position by all respondents with RII of (0.861). Each of them separately ranked it in the first position with RII of (0.839) and (0.889) respectively. This means ignoring the contractors to use new formwork in the construction industry Although the UNRWA engineers follow this issues. Damaged formwork affects the quality by producing a honeycomb or porous concrete surface or surface cracks which will allow for moisture penetration and cause corrosion of steel bars. Hoe (2009) emphasized that this factor is an important factor related to defects due to structural and architectural construction.
117
On the other hand, it is shown that, " implementation of internal and external paint improperly " was ranked in the second position by all respondents with RII of (0.839). Each of them separately ranked it in the second position with RII of (0.833) and (0.846) respectively. Paints are like any chemical products which can be affected with any defect, even if simple. it considered a continuous maintenance item either for redecoration or renewal purposes. But sometimes it can become a major maintenance item if it is performed improperly. Improper paint type selection, manufacturing, storage, and execution will cause the paint defects. As well as, poor handling of wall surfaces may cause the paint defects. Furthermore, moisture or dampness was a major reason for the coming out paints defects. There are many causes of peeling external paint in UNRWA school, among of them were: bad quality of materials due to closure of Palestinian borders, fraud in painting, painting in humid weather, and dampness or water leakage which necessitate complete removal of the original paint and cleaning the surface. Obtained results agreed with Hoe (2009) and who found that, this factor was in the third position in the group related to defects due to structural and architectural construction. Al- Farra ( 2011) emphasized that this factor is an important factor related to defects due to structural and architectural construction. "Inadequate insulation against water and sanitary works" was ranked in the third position by all respondents with RII of (0.709). Each of them separately ranked it in the third position with RII of (0.689) and (0.735) respectively. This meaning there are many water seepage problems, especially in the bathroom area in UNRWA schools, where water leaks from the above level to the level below. This represented in insufficient treatment and insulation for water supply system due to poor workmanship. This leads to corrosion of pipes and joint quickly, which cause water leakages and dampness problems. Also, due to shoddy water proofing works by contractors and insufficient supervision in conducting the necessary tests and inspections for plumbing works. Water proofing and drainage are two of the items where contractors lack experience. Most of the time is performed wrongly or inadequately, especially at the joints, which results in water seepage through the roof ceiling, or block wall. Most buildings lack proper roof drainage.
118
The obtained results agreed with Hoe (2009) who found that, this factor was in the first position in the group related to defects due architectural and structural construction. AlFarra ( 2011) and Assaf et al.(1996) emphasized that this factor is an important factor related to defects due to structural and architectural construction. Finally, it is shown that, " Inaccuracy of dimensions and measurement " was ranked in the last position by all respondents with RII of (0.456). Each of them separately ranked it in the last position with RII of (0.450) and (0.463) respectively. It is worth noting that the respondents feel that inaccurate measurement is not an important defect that affects maintenance. Situations where the contractor under measures or over measures the sizes of building elements, the location and material ratios, for example increasing the gap between door and door frame or window and window frame are not considered to have any effects on maintenance. This means ignoring this factor, where the UNRWA Eng.'s keep the maintenance contractor measures or the sizes of building elements, the location and the material ratios to be correct. The obtained results agreed with Hoe (2009) who found that, this factor was in the last position in the group related to defects due architectural /structural construction. Spearman rank correlation coefficient: For the group of factors related to defects/errors due to architectural and structural construction in construction stage, the correlation coefficient equals to 0.889 with Pvalue (Sig.) = 0.0001. The P-value is less than the level of significance, = 0.05, so there is a total agreement between the UNRWA Eng.'s and maintenance contractors in this group.
4.3.4 Factors related to defects/errors due to construction equipment Table 4.14 was tabulated from five (5) factors related to defects/errors due to construction equipment in construction stage ranked from high to low.
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Table 4.14: Rank and RII of factors related to defects due construction equipment
Factors The negligence of the periodic maintenance of the equipment The lack of the required spare parts elements of the equipment Not taking into mind the availability of the equipment used in the maintenance in the local market during implementing Inadequate quality performance and quantity of the equipment Misuse of equipment All factors
UNRWA Eng.'s
maintenance contractors RII Rank
RII
Rank
0.706
1
0.728
0.611
2
0.522
All respondents RII
Rank
1
0.715
1
0.625
2
0.617
2
3
0.515
4
0.519
3
0.450
4
0.522
3
0.481
4
0.439 0.546
5
0.427 0.563
5
0.434 0.553
5
" The negligence of the periodic maintenance of the equipment " was ranked by all respondents in the first position with RII of (0.715). Each of them separately ranked it in the first position with RII of (0.706) and (0.728) respectively. This emphasizes that, this is the most important factor of defects/errors used by all respondents which affecting on maintenance of UNRWA schools in construction stage in this group because, periodically inspecting, servicing and cleaning equipment and replacing parts lead to prevent sudden failure and process problems and, increase the period of service for maintenance equipment. On the other hand, it is shown that, " The lack of the required spare parts elements of the equipment " was ranked in the second position by all respondents with RII of (0.617). Each of them separately ranked it in the second position with RII of (0.611) and (0.625) respectively. This means the use of poor quality spare parts will necessitate rework, additional maintenance and replacement of poor quality spare parts. Having enough equipment will help in performing the job properly. Lack of enough equipment will cause the contractor to perform his work by hand where a special tool is required, as when a level hose is used where a theodolite is needed for leveling roof slab for drainage. As a result, the job will be done poorly and requires continuous maintenance after some time of operation. Finally, it is shown that, " Misuse of equipment " was ranked in the last position by all respondents with RII of (0.434). Also, each of them separately ranked it in the last
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position with RII of (0.439) and (0.427) respectively. This means ignoring the respondents to this factor, where is the maintenance contractors have a good experience in deal with construction equipment which lead to perform a good quality job. Spearman rank correlation coefficient: For the group of factors related to defects/errors due to equipment construction in construction stage, the correlation coefficient equals to 0.822 with P-value (Sig.) = 0.0002. The P-value is less than the level of significance, = 0.05, so there is a good agreement between the UNRWA Eng.'s and maintenance contractors in this group.
4.3.5 Factors related to defects/errors due to construction material Table 4.15 shows the opinion of respondents about the factors related to defects/errors due to material construction in construction stage according to relative importance index ranked from high to low. Table 4.15: Rank and RII of factors related to defects due construction materials UNRWA Eng.'s Factors Choice of substandard materials that have a poor quality of specifications Selection of material that is unsuitable for existing climatic conditions Selection of cheap finishing materials price due to lack of fund Ignore determine the time and duration of storage and handling of materials and choosing the appropriate places Ignore the basic physical and chemical properties of materials use of non-durable materials (which does not stand up) The use of new materials are not known and did not examine the details of their quality in construction before in the local market Use expired material All factors
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.767
1
0.728
1
0.750
1
0.761
2
0.625
2
0.703
2
0.594
3
0.566
4
0.582
3
0.578
4
0.544
7
0.563
4
0.556
5
0.566
5
0.560
5
0.528
6
0.581
3
0.551
6
0.472
8
0.544
6
0.503
7
0.506 0.595
7
0.441 0.574
8
0.478 0.586
8
121
As notice in Table 4.15, it is shown that, " Choice of substandard materials that have a poor quality of specifications " was ranked in the first position by all respondents with RII of (0.750). Each of them separately ranked it in the first position with RII of (0.767) and (0.728) respectively. The shortage of project materials is one of the clearest factors causes cost overrun and delay of project. Generally, materials for construction project are provided by two ways in Gaza strip, one from Israel through borders with Gaza strip, and the other way by underground tunnels with Egypt that excavated after Israeli siege to Gaza strip. The political and economic situations affected the availability of the materials required because major borders are controlled by Israel and instability of tunnels situation with Egypt. This shortage of materials and equipment's resulted in increase of its price and hence increasing project cost. According to Palestinian contractors union, the contractors were suggested to use local materials and products in their construction projects to avoid any delay and cost overrun due to interrupted closer of Gaza border which hinder them to getting required materials for their projects. So, it's important to use suitable materials produced locally after passing all required tests where are cheap and easy to get at any time. Also, cheap or low quality material needs continuous repair and maintenance. On the other hand, it is shown that, " Selection of material that is unsuitable for existing climatic conditions " was ranked in the second position by all respondents with RII of (0.703). Each of them separately ranked it in the second position with RII of (0.761) and (0.625) respectively. This means the designer should always select the color and type of a building’s exterior finishing material to suit the weather and environmental conditions of the building, e.g. not painting buildings with dark colors in a dusty area where they require a lot of cleaning, or using paints which cannot resist heat and humidity. Obtained results agreed with Hoe (2009) who found that, this factor was in the second position in the group related to defects due to construction material. Assaf et al.(1996) emphasized that this factor is an important factor related to defects due to construction material. Finally, it is shown that, " Use expired material" was ranked in the last position by all respondents with RII of (0.478). Also, the responding maintenance contractors ranked
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this factor in the last position with RII of (0.441), while the UNRWA Eng.'s ranked it in the seventh position with RII of (0.506). This means ignoring of this factors because, use of expired material at the construction stage will require the owner to replace it in short time after the building in operation . Spearman rank correlation coefficient: For the group of factors related to defects/errors due to material construction in construction stage, the correlation coefficient equals to 0.977 with P-value (Sig.) = 0.0007. The P-value is less than the level of significance, = 0.05, so there is a total agreement between the UNRWA Eng.'s and maintenance contractors in this group Factors used for defects/errors in construction stage.
4.3.6 Comparison between all groups of factors leading to errors / defects in constriction stage Table 4.16 shows the opinions of the respondents about the groups of factors leading to errors/defects in construction stage according to relative index from high to low. Table 4.16: Rank and RII of groups related to defects / errors in construction stage
Factors factors related to defects/errors due to lack of periodic checking and monitoring of construction factors related to defects/errors due to contractor administration and his staff factors related to defects/errors due to architectural and structural construction factors related to defects/errors due to construction material factors related to defects/errors due to construction equipment All factors
UNRWA Eng.'s
maintenance contractors RII Rank
RII
Rank
0.706
1
0.717
0.688
2
0.570
All respondents RII
Rank
1
0.711
1
0.704
2
0.695
2
4
0.634
3
0.598
3
0.595
3
0.574
4
0.586
4
0.546
5
0.563
5
0.553
5
0.614
0.639
0.624
" factors related to defects/errors due to lack of periodic checking and monitoring of construction " was ranked in the first position by all respondents with RII of (0.711). Each of them separately ranked it in the first position with RII of (0.706) and (0.717)
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respectively. This emphasizes that, this is the most important group used by all respondents which affecting maintenance of UNRWA schools building in construction stage. Because, when the construction inspection increases, the quality increases. Therefore, the maintenance needed is reduced. On the other hand, it is shown that, " factors related to defects/errors due to contractor administration and his staff " was ranked in the second position by all respondents with RII of (0.695). Each of them separately ranked it in the second position with RII of (0.688) and (0.704) respectively. This emphasizes that, this is the most important group used by all respondents which affecting maintenance of UNRWA schools building in construction stage. Because, the experiences of contractors and his communication with owners will avoid a lot of maintenance defects. Finally, it is shown that, " factors related to defects/errors due to construction equipment " was ranked in the last position by all respondents with RII of (0.553). Each of them separately ranked it in last position with RII of (0.546) and (0.563) respectively. This implies that this group is thought to have little effect on UNRWA schools buildings . Spearman rank correlation coefficient: For the group of factors related to groups factors leading to defects / errors in construction stage, the correlation coefficient equals to 0.883 with P-value (Sig.) = 0.0002. The P-value is less than the level of significance, = 0.05, so there is a good agreement between the UNRWA Eng.'s and maintenance contractors in this group.
4.3.7 Ranking and RII of all factors leading to errors/defects in construction stage Table 4.17 was tabulated from 39 different factors leading to the defects/errors in construction stage. Using RII, the rank order for the most important factors from the view point of the respondents is indicated. As shown in Table 4.17 most of the respondents graded these factors from important to very important.
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Table 4.17: Ranking and RII of all factors leading to errors/defects in construction stage UNRWA Eng.'s
maintenance contractors
All respondents
Factors
RII
Rank
RII
Rank
RII
Rank
contract awarding on lowest bidders price
0.906
1
0.882
2
0.896
1
0.839
4
0.889
1
0.861
2
0.861
2
0.831
6
0.848
4
inspection
0.850
3
0.846
3
0.848
3
Contractor administration
0.833
6
0.846
5
0.839
6
inspection
0.833
5
0.846
4
0.839
5
Civil /architecture Construction
0.700
11
0.831
7
0.756
7
Contractor Administration
0.767
8
0.728
9
0.750
8
Construction materials
0.772
7
0.669
11
0.728
9
inspection
0.706
10
0.728
10
0.715
10
0.689
12
0.735
8
0.709
11
0.761
9
0.625
17
0.703
12
0.678
13
0.588
21
0.639
13
0.656
14
0.574
27
0.620
14
0.617
15
0.618
19
0.617
15
0.600
16
0.625
18
0.617
16
0.572
19
0.662
13
0.611
17
0.550
22
0.647
14
0.592
18
0.533
24
0.662
12
0.589
19
inspection
0.539
23
0.639
15
0.582
20
civil /architecture Construction
0.594
17
0.566
28
0.582
21
Construction materials
The damage due to the multi-use of formwork in the construction industry insufficient testing procedures during preliminary of water feeding and sewerage networks Accelerate in execution to avoid delay and lack of quality Lack of periodic inspection and monitoring improperly performed of paint works Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards. Choice of substandard materials that have a poor quality of specifications Ignore of owner monitoring and checking importance The negligence of the periodic maintenance of the equipment Inadequate insulation against water and sanitary works Selection of material that is unsuitable for existing climatic conditions Lake of workers experience and bad workmanship Lack of efficiency and expertise of the contractor engineers and inability to read drawing Non-compliance with specifications The lack of the required spare parts elements of the equipment The contractor engineer not resident fully in the site Inadequate curing the casted parts well Lack of experience and qualification of inspector Weakness and lack of homogeneity of concrete mix component or lack of compliance with the specifications components (in case of casting at the site) Selection of cheap finishing materials price due to lack of fund
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Group Contractor administration civil /architecture Construction
Construction equipment civil /architecture Construction Construction materials Contractor administration Contractor administration Contractor administration Construction equipment contractor administration civil /architecture Construction
Continue - Table 4.17: Ranking and RII of all factors leading to errors/defects in construction stage UNRWA Eng.'s
Factors Remove formwork of concrete early before the allowed time Lack of contractor communication with the designer and owner Ignore determine the time and duration of storage and handling of materials and choosing the appropriate places Ignore the basic physical and chemical properties of materials Weakness of inspection rule in implementing corrective actions during construction and not to give full powers to the inspector use of non-durable materials (which does not stand up) Lack of sufficient vibration Weakness contiguity and coherence between materials (syrups) Excavations with mechanical excavations tools near the existing building Inadequate concrete cover for reinforced concrete Lake of soil compaction Not taking into mind the availability of the equipment used in the maintenance in the local market during implementing Cold spacers between the new and old concrete The use of new materials are not known and did not examine the details of their quality in construction before in the local market Inadequate quality performance and quantity of the equipment Use expired material
maintenance contractors
All respondents
RII
Rank
RII
Rank
RII
Rank
0.567
20
0.581
24
0.573
22
civil /architecture
0.528
25
0.632
16
0.573
23
contractor
0.578
18
0.544
34
0.563
24
Construction materials
0.556
21
0.566
29
0.560
25
Construction materials
0.528
26
0.581
23
0.551
26
inspection
0.528
27
0.581
25
0.551
27
Construction materials
0.522
29
0.581
22
0.548
28
civil /architecture
0.489
32
0.581
26
0.529
29
civil /architecture
0.467
36
0.603
20
0.525
30
civil /architecture
0.500
31
0.552
32
0.522
31
0.483
34
0.566
30
0.519
32
0.522
28
0.515
36
0.519
33
Construction equipment
0.483
33
0.559
31
0.516
34
civil /architecture Construction
0.472
35
0.544
33
0.503
35
Construction materials
0.450
37
0.522
35
0.481
36
0.506
30
0.441
38
0.478
37
Inaccuracy of dimensions and measurement
0.450
38
0.463
37
0.456
38
Misuse of equipment
0.439
39
0.427
39
0.434
39
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Group
civil /architecture Construction civil /architecture Construction
Construction equipment Construction materials civil /architecture Construction Construction equipment
Spearman rank correlation coefficient: For the group of factors related to errors/defects in construction stag, the correlation coefficient equals to 0.883 with P-value = 0.0002. The P-value is less than the level of significance, = 0.05, so there is a good agreement between the UNRWA Eng.'s and maintenance contractors toward the opinions in this study. Other descriptive statistics for the factors related to defects/errors in construction stage attached in the tables from (6 to 10) at Annex 4.
4.3.8 Top ten factors leading to the errors/defects in construction stage Table 4.18 was tabulated from 10 different factors leading to the errors/defects which affecting maintenance of UNRWA schools buildings in construction stage. Using RII, the rank order for the most important factors from the view point of the respondents is indicated. As shown in Table 4.18 most of the respondents graded these factors from important to very important. Table 4.18: Top ten factors leading to errors/defects in construction stage
All respondents
The factors contract awarding on lowest bidders price The damage due to the multi-use of formwork in the construction industry Accelerate in execution to avoid delay and lack of quality insufficient testing procedures during preliminary of water feeding and sewerage networks improperly performed of paint works Lack of periodic inspection and monitoring Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards. Choice of substandard materials that have a poor quality of specifications Ignore of owner monitoring and inspection importance The negligence of the periodic maintenance of the equipment
Group
RII
Rank
0.896
1
0.861
2
0.848
3
0.848
4
inspection
0.839
5
civil /architecture
0.839
6
inspection
0.756
7
contractor administration
0.750
8
Construction materials
0.728
9
inspection
0.715
10
Construction equipment
contractor administration civil /architecture Construction Contractor administration
" awarding the contract on the lowest price of the contractor " which related to factors leading to defects/errors due to contractor administration and his staff group in construction stage was ranked in the first position by all respondents with RII of
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(0.896). This emphasizes that, this is the most important factor used by all respondents related to defects/errors due to contractor administration and his staff during construction stage. This due to UNRWA awarding the projects depend on low price of the contractor. The method of awarding maintenance contracts play a big role in defects to contractor administration and his staff in construction stage. When public maintenance contracts are awarded based on competitive bidding, with the selection of the lowest bidder, The least bidder will try to complete the work with the lowest bidder. " The damage due to the multi-use of formwork in the construction industry " which related to factors leading to defects/errors due to civil /architecture construction group in construction stage was ranked in the second position by all respondents with RII of (0.861). This means ignoring the contractors to use new formwork in the construction industry Although the UNRWA engineers follow and supervise this issues. Damaged formwork affects the quality by producing a honeycomb or porous concrete surface or surface cracks which will allow for moisture penetration and cause corrosion of steel bars. Hoe (2009) emphasized that this factor is an important factor related to defects due to structural and architectural construction. " Accelerate in execution to avoid delay and lack of quality " which related to factors leading to defects/errors due to contractor and his staff group in construction stage was ranked in the third position by all respondents with RII of (0.848). This means the maintenance contractors tend to do the job which needs tools or equipment quickly to reduce rental time. In addition they always tend to select cheap quality materials to save money. " insufficient testing procedures during preliminary of water feeding and sewerage networks " which related to factors leading to defects/errors due to lack of inspection in construction stage was ranked in the fourth position by all respondents with RII of (0.848). This emphasizes that, this is the most important factor used by all respondents related to defects/errors due to lack of inspection during construction stage. Poor supervision which is represented by insufficiency in conducting the required tests for plumbing, and sanitary works and poor workmanship which is represented in poor treatment or insulation of underground galvanized water supply system were the main causes of pipe and waterproofing defects. Many supervisors don't give the required
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importance to conduct the necessary tests and inspections for plumbing works. Undoubtedly, implementation of periodic inspection for the plumbing works for each school buildings will show any leaks in plumbing pipes during construction phase. This underlines the role of supervision in minimizing the emergence of such defects in the school buildings. So, all plumping and sanitary works should be carried out under supervision of a mechanical engineer with experience not less than five years, and the contractor should carry out all the required tests to prevent any leaks in the water supply system and plumping works firstly for every floor separately, and after this for all floors in the same time. Among of these tests were : pressure tests and hydrostatic pressures. The obtained results agreed with Al-Farra (2011), who emphasized that this factor is an important factor that in the group related to defects due to lack of periodic checking and monitoring. " Applying of painting layers improperly " which related to factors leading to defects/errors due to civil and architecture was ranked in the fifth position by all respondents with RII of (0.839). Paints are like any chemical products which can be affected with any defect, even if simple. it considered a continuous maintenance item either for redecoration or renewal purposes. But sometimes it can become a major maintenance item if it is performed improperly. Improper paint type selection, manufacturing, storage, and execution will cause the paint defects. As well as, poor handling of wall surfaces may cause the paint defects. Furthermore, moisture or dampness was a major reason for the coming out paints defects. There are many causes of peeling external paint in UNRWA school, among of them were: bad quality of materials due to closure of Palestinian borders, fraud in painting, painting in humid weather, and dampness or water leakage which necessitate complete removal of the original paint and cleaning the surface. Obtained results agreed with Hoe (2009) and who found that, this factor was in the third position in the group related to defects due to structural and architectural construction. Al- Farra ( 2011) emphasized that this factor is an important factor related to defects due to structural and architectural construction. " Lack of periodic inspection and monitoring" which related to factors leading to defects/errors due to lack of inspection in construction stage was ranked in the sixth position by all respondents with RII of (0.839). This emphasizes that, this is the most
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important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance schools in construction stage in this group. This means the importance of this factor where, there is inspection practice in UNRWA school buildings but not periodic due to the pressure of works, if the periodic inspection increases, quality increases. Therefore, the maintenance needed is reduce. Obtained results agreed with Assaf et al.(1996) and Buys & Roux (2014) who emphasized that this factor is an important factor that in the group related to lack of inspection from the viewpoint of the maintenance contractor. " Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards.." related to factors leading to defects/errors due to contractor administration and his staff group in construction stage was ranked in the seventh position by all respondents with RII of (0.756). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance school in construction stage in this group because, at the end of the project duration, the contractor is tray to avoid liquidated damage due to his delays, and this leads to ignore the quality and required time for every activity as in contract specifications. " Choice of substandard materials that have a poor quality of specifications " which related to factors leading to defects/errors due to construction material group in construction stage was ranked in the eighth position by all respondents with RII of (0.750). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance. Cheap or low quality material needs continuous repair and maintenance. Cheaper materials often required more frequent maintenance and may have a shorter working life than the more expensive alternative (arditi and nawakorawit, 1999). " Ignore of owner monitoring and inspection importance)" which related to factors leading to defects/errors due to lack of inspection in construction stage was ranked in the ninth position by all respondents with RII of (0.728). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors affecting on maintenance. As a result of the large number of projects, which are supervised by the ICIP in a short period of time, and with a shortage
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of technical staff of engineers and observers, which is reflected on the importance of monitoring and follow-up, and the quality of work carried out. " The negligence of the periodic maintenance of the equipment " which related to factors leading to defects/errors due to construction equipment group in construction stage was ranked in the tenth position by all respondents with RII of (0.715). This emphasizes that, this is the most important factor of defects/errors used by both UNRWA Eng.'s and maintenance contractors which affecting on maintenance of UNRWA school in construction stage in this group because, periodically inspecting, servicing and cleaning equipment and replacing parts lead to prevent sudden failure and process problems and, increase the period of service for maintenance equipment.
4.4
Part four : Factors related to effects of faulty design and construction on maintenance of UNRWA schools .
This part will show the results of the responding UNRWA engineers and maintenance contractors regarding 8 factors used below:
4.4.1
Factors related to effects of faulty on maintenance of UNRWA schools .
Table 4.19 shows the opinion of respondents about the factors related to effects of faulty design and construction on maintenance of UNRWA schools according to relative importance index ranked from high to low. Table 4.19: Rank and RII of factors related to effects of faulty on maintenance
Factors Increase in maintenance works Increase in maintenance time\duration Increase in maintenance budget Increase in maintenance workforce Increased maintenance frequency Difficulty in maintenance planning Decreased building age Lower maintenance quality All factors
UNRWA Eng.'s
maintenance contractors RII Rank 0.757 3
RII 0.717
Rank 2
0.739
1
0.713
0.656 0.650 0.578 0.611 0.611 0.550 0.639
3 4 7 5 6 8
0.809 0.794 0.735 0.647 0.625 0.618 0.712
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All respondents RII 0.734
Rank 1
5
0.728
2
1 2 4 6 7 8
0.722 0.712 0.646 0.627 0.617 0.579 0.671
3 4 5 6 7 8
As notice in Table 4.19 , all the respondents ranked " Increase in maintenance works " in the first position with RII of (0.734). The responding UNRWA Eng.'s ranked this factor in the second position with RII of (0.717), while the maintenance contractors ranked it in the third position with RII of (0.757). Due to many design and construction defects in UNRWA school buildings will inevitably necessitate a larger scope and volume of maintenance works. The obtained results agreed with Hoe (2009) who emphasized that "increase in maintenance work " was ranked in the most important effects . On the other hand, it is shown that, " Increase in maintenance time\duration " was ranked in the second position by all respondents with RII of (0.728). The responding UNRWA Eng.'s ranked this factor in the first position with RII of (0.739), while the maintenance contractors ranked it in the fifth position with RII of (0.713). This means the respondents also strongly believe that increase in maintenance time/duration to be the consequences of faulty design and construction. This due to severe and complex defects that required longer duration to fix and repair these defects. The obtained results in the first line of Hoe (2009) study. "Increase in maintenance budget" was ranked in the third position by all the respondents with RII of (0.722). Also, the responding UNRWA Eng.'s ranked this factor in the third position with RII of (0.656), while the maintenance contractors ranked it in the first position with RII of (0.809). Because, in addition to need longer duration to fix and repair defects, finances needed to perform maintenance would increase in tandem with building defects as part of the cost for performing maintenance operations, buying materials and equipment's. Finally, it is shown that, " Lower maintenance quality" was ranked in the last position by all respondents with RII of (0.579). Each of them separately ranked it in the last position with RII of (0.550) and (0.618) respectively. This means ignoring this factor by responding. The obtained results of this study agreed with Hoe (2009) study results .
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Spearman rank correlation coefficient: For the group of factors related to the factors related to effects of faulty on maintenance of UNRWA schools, the correlation coefficient equals to 0.970 with P-value (Sig.) = 0.0016. The P-value is less than the level of significance, = 0.05, so there is a total agreement between the UNRWA Eng.'s and maintenance contractors in this group toward the opinions in this study. Other descriptive statistics for the factors related to effects of faulty on maintenance attached in the table 11 at Annex 5.
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5. 5.1
Chapter 5: Interviews And Case Studies
Structured interview
5.1.1 Introduction To explore and identify the most effective factors affecting in maintenance of school buildings, a structured interview related of maintenance and defects concept was conducted. The interviews designed to facilitate flow of ideas. The followings open end questions were listed to give the interviewee an indication of information requested. -
What is the main factors affecting in maintenance of schools building ?
-
What is the main causes of errors /defects which affecting of school building ?
-
What is the main strategies and solution to minimize of design defects which affecting of school building ?
-
What is the main strategies and solution to eliminate of construction defects which affecting of school building? Table 5.1: Profile of interviews
No 1 2 3 4 5
Interviewee Architect engineer Civil engineer Site engineer Site engineer Quantity surveyor Total of interviewee
Interviewee Sector Working in building design Working in structure design Working in construction Working in maintenance Working in building design
No of years experiences 15 20 25 15 25
No of interviews 2 2 3 3 1 11
5.1.2 Interviews finding The collective opinions and inputs relating to number of structured interview, questions are summarized below: All the interviews agreed that there are a different types of defects, some of them not affect on maintenance of schools, but others types of these errors were affected on
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maintenance of schools. Anyway there are common types of defects, among of them : Cracks (in floor, walls and beams), detachment (plaster from walls, paint peeling), Defects in structural concrete, defects in masonry walls, Plaster defects, Paint defects ,Defects in floor components, Blemishes (scaling, honeycomb ), Corrosion (steel ), Water leaks (plumbing ), waterproofing defects, tile defects, Doors, windows and joinery defects. All the interviews agreed that most of maintained school buildings conducted corrective maintenance type which mainly belongs to emergence of various defects such as water leakage, wall dampness, paint peeling, cracks, concrete deterioration . All the interviews agreed that all types of defects/errors can be grouped into four categories : design deficiencies, materials deficiencies, construction deficiencies and subsurface deficiencies. The following of describes the major categories were summarize as follows according to interviewee : • Design deficiencies: Buildings and systems (designed by professionals such as engineers) do not always work as specified; this can result in a defect. Typical design deficiencies relate to building outside the specified code. A typical design defect is roofs that result in water penetration, poor drainage or inadequate structural support. •
Material deficiencies: The use of inferior building materials can cause significant
problems such as windows that leak or fail to perform even when properly installed. • Construction
deficiencies: Poor quality workmanship can result in long lists of defects,
e.g. plumbing leaks. • Subsurface
deficiencies: Many school building are built on hills or other areas where it
is difficult to provide a stable foundation. A lack of a solid foundation may result in cracked foundations or floor slabs as well as other damage to the building. Subsurface conditions that are not properly compacted or prepared . All the interviews agreed that the defects/errors affect on school buildings maintenance cost.
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All the interviews agreed that the design stage is very important phase of the project. Special care should be taken since it has a vital effect on the amount of maintenance woke that will be needed after the building completed. The following suggestions were given for eliminating of design errors/defects: -
Provide technical update to designer.
-
Improve communication between different members of the design, owner, maintenance staff and contractors .
-
Aligning material performance against adverse weather conditions.
-
Preventing impacts from occupants and loads.
-
Preventing water leakage that cause other defects.
-
Improve specifications.
-
Improve design clarity, design details, and layout.
-
The designer must take into account maintenance considerations during the design and supervision stages by choosing of durable materials.
All the respondents agreed that a construction defects as a consequence of wrong decision is one of the most common causes of early deterioration. Construction contractors should be aware about materials selection, construction techniques used and skilled labor hiring. The following suggestions were given for minimizing of construction errors/defects: -
Strict monitoring during construction.
-
Quality controls and quality assurance (QC/QA) program must be improved on the site to achieve an acceptable performance standard and practical specifications.
-
Construction contractors should be aware about materials selection, construction techniques used and skilled labor hiring.
-
maintenance contractor should make sure that all used construction material will serve the buildings intended use and tolerate the environmental conditions.
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-
increase the level of interest in the plumbing and sanitary works as well as in insulation works in school buildings in Gaza Strip .
-
improved training of craftsmen, supervisors , and all members of the team engaged in the construction of buildings to avoid any constructional defects .
-
use suitable materials appropriate to climatic conditions.
5.2 5.2.1
Case studies Introduction
Two UNRWA school projects were selecting for validating the results of this research. These projects were selected, because they are representing the common building types executed by UNRWA. The projects are easily accessible to collect the data to get indepth information about design and construction defects /errors that affecting on maintenance of UNRWA school projects. The details of the two case studies are presented. 5.2.2 Case study (A): School No.1 This project consists of main building with ground floor, first floor, second floor and third floor. With total built up area is 5500 m2. The main building consists of all standard school facilities in addition to canteen, concrete shed, boundary / retaining wall, and landscaping works. The full detail design was prepared by design division . The supervision was carried out by construction division in UNRWA at GS. Other information of project summarized below in Table 5.2 . Table 5.2: Summary of case study No (1) information
Project Name Project Location Starting Date Project duration Age of building Project Supervision Source of fund Project budget contractor
School No. 1(case study A) Construction of kingdom of Bahrain prep . boys school Gaza 2010 44 weeks 5 years UNRWA Bahrain 1,600000 $ Khwaiter company
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Continue - Table 5.2: Summary of case study No (1) information School No. 1(case study A) Corrective maintenance
Type of maintenance
In case study (A) it is noted that the main defects affecting maintenance of school building as followings: Paint peeling from external walls. Plumbing and sanitary (leaks in water supply and sewer systems). Door and lock system. Interior walls Dampness. 5.2.3 Case study (B): School No.2 This project consists of main building with ground floor, first floor, and second floor. With total built up area is 4300 m2. The main building consists of all standard school facilities in addition to canteen, concrete shed, boundary / retaining wall, and landscaping works. The full detail design was prepared by design division. The supervision was carried out by construction division in UNRWA, Gaza. Other information of project summarized in Table 5.3. Table 5.3: Summary of case study No (2) information
Project Name Project Location Starting Date Project duration Age of building Project Supervision Source of fund Project budget contractor Type of maintenance
School No 2 (case study B) Construction of Al-Amal Girls school khanyounis 2006 40 weeks 9 years UNRWA Japan 1,200000 $ Salama company Preventive maintenance
In case study (B) it is noted that the main defects affecting maintenance of school building as followings: Paint peeling from external walls. Plumbing and sanitary (leaks in water supply and sewer systems). Door and lock system.
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Security screen and balustrade. Cracks Defects between walls and structural elements. 5.2.4 Data collection The data were collected through structured interviews with the project team leader, design team, and maintenance team from each project. These participants were selected as they possessed the greatest understanding of type of defects and their effects on maintenance of school building . 5.2.5 The case studies finding It is noted that the two case studies had a difference between the budgeted amount, The building type, location, number of floors, size and area, and type of maintenance which, signify affect on the maintenance of school buildings. The case studies have defects/errors as a result of deferent causes. Among of these causes poor design, bad workmanship, poor materials and equipment. Peeling of external paint defects in external walls of school No.(1) due to many causes of defects, among of them were: Moisture and dampness or water leakage, improper paint type, manufacturing and Fraud in painting, while the main causes of painting defects in school No. (2) were due to aging of building, vandalism and culture of end user, and location of school near to khan younis sea. Obtained results in case study agreed with the survey results which summarized in Table 4.10 and Table 4.18 and include : applying of painting layers improperly, Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards, Selection of material that is unsuitable for existing climatic conditions, selecting of exterior finishing and isolation material not relating to climatic condition in design stage and Lack of technical updating and adequate training of staff and lack of awareness of construction technology. Plumbing and sanitary defects of school No.(2) due to different causes, among of them were : Bad quality of materials used, poor design, lack of periodic inspection and negligence of tests. Obtained results in case study agreed with the top ten factors of the defects causes in survey results which discussed and summarized in Table 4.10 and Table 4.18 and include : Lack of periodic inspection and monitoring, choice of
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substandard materials that have a poor quality of specifications, Not specifying quality assurance &quality control (QA/QC) procedures, Lack of auditing and archiving of approved as-built drawing documents electronically after execution, Inadequate insulation against water and sanitary works and insufficient testing procedures during preliminary of water feeding and sewerage networks. Door and lock system defects of school No.(1) and school No.(2) due to different causes of defects, among of them were : selection of bad quality materials, dampness in the bottom level of panel and frames and poor design for frames and panels. Obtained results in case study agreed with the top ten factors of the defects causes in survey results which discussed and summarized in Table 4.10 and Table 4.18 and include: Lack of periodic inspection and monitoring, Choice of substandard materials that have a poor quality of specifications, Inadequate insulation against water and sanitary works, Lack of local specifications and standards related of requirements of materials and workmanship and inadequate (QA/QC) programs during design stage. Cracks between walls and structural elements defects in school No (1) due to variation of thermal expansion characteristics between concrete and block, weak bond between block and concrete and improper curing. Obtained results in case study agreed with the top ten factors of the defects causes in survey results which discussed and summarized in Table 4.10 and Table 4.18 and include: Lack of attention to the design details and the concrete block walls and the intersection with the structural elements, Remove framework of concrete early before the allowed time, accelerate in execution to avoid delay and lack of quality, and the multi-use of formwork in the construction industry Interior walls Dampness defects of school No.(1) and school No.(2) due to many causes, among of them were : water leakage from plumbing works under the tiles, dripping fixtures like basin, slow drains and poor finishing of external walls and windows lintel. Obtained results in case study agreed with the top ten factors of the defects causes in survey results, which discussed and summarized in Table 4.8 and Table 4.18 and include: Insufficient testing procedures during preliminary of water feeding and sewerage, Lack of periodic inspection and monitoring, Inadequate insulation against water and sanitary works, Selection of material that is unsuitable for existing climatic conditions and Poor communication between the design team and the
140
crew of maintenance / implementation. The summary for other type of defects/errors with possible causes and solution for case studies shown in Table 5.6 . Table (5.4) shows ranking group of factors related to defects/errors in design stage of the interview in the case studies, it was observed that the most important group factors causes defects/errors in design stage were: factors related to defects/errors due to owner administration and his staff with rank equals "1" were ranks equal “2” in the result of survey, factors related to defects/errors in architecture design with rank equals “2’ were ranks equal “3” in the result of survey, factors related to defects/errors due to drawing with rank equals “3’ were ranks equal “1” in the result of survey, factors related to defects/errors in civil/ structural design with rank equals “4’ were ranks equal “5” in the result of survey, factors related to defects/errors due to specification with rank equals “5’ were ranks equal “4” in the result of survey. Table 5.4: Rank group of factors related to defects/errors in design stage (case study) Factors factors related to defects/errors due to drawing factors related to defects/errors due to owner administration and his staff factors related to defects/errors in architecture design factors related to defects/errors due to specification factors related to defects/errors in civil/ structural design
Rank based on Case study 3
Rank based on survey 1
1
2
2
3
5
4
4
5
Table 5.5 shows ranking group of factors related to defects/errors in construction stage of the interview in the case studies were: factors related to defects/errors due to contractor administration and his staff with rank equals "1" were ranks equal “2” in the result of survey, factors related to defects/errors due to lack of periodic checking and monitoring of construction with rank equals “2’ were ranks equal “1” in the result of survey, factors related to defects/errors due to construction material with rank equals “3’ were ranks equal “4” in the result of survey, factors related to defects/errors due to civil/ construction with rank equals “4’ were ranks equal “3” in the result of survey, factors related to defects/errors due to construction equipment with rank equals “5’ and also ranks “5” in survey.
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Table 5.5: Rank group of factors related to defects/errors in construction (case study) Factors
Rank based on Case study
Rank based on survey
2
1
1
2
4
3
3
4
5
5
factors related to defects/errors due to lack of periodic checking and monitoring of construction factors related to defects/errors due to contractor administration and his staff factors related to defects/errors due to civil/ construction factors related to defects/errors due to construction material factors related to defects/errors due to construction equipment
5.2.6 The major findings of the case studies are summarized as follows:There are many type of defects /errors were summarized in these case studies, among of them were: peeling of paint defects, plumbing and sanitary defects, Cracks between walls and structural elements, wooden door frame and panels defects, and dampness of walls. The main causes of defects /errors were summarized in these case studies, among of them were: bad workmanship, bad quality of materials used, poor design and construction . School Buildings characteristics (age of building, size, and number of floors ), vandalism and culture of occupancy other important factors were affects in maintenance of school buildings not covered in this study. 5.2.7 Summary According to findings in the case study, the common recommendation by the designers compared by the results of the questionnaire is as following: -
The designer must take into account maintenance considerations during the design and supervision stages by choosing of durable materials.
-
Preventing water leakage that cause other defects.
-
increase the level of interest in the plumbing and sanitary works as well as in insulation works in school buildings in Gaza Strip.
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-
Construction contractors should be aware about materials selection, construction techniques used and skilled labor hiring.
-
The designers should consider the feedback by the maintenance teams to reduce the repetition of maintenance work.
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Table 5.6:Summary for type of defects/errors with possible causes and solution (case studies)
Defects
Possible Causes
Solution strategies
1.Paint peeling from external walls and Improper paint type, manufacturing and All paint materials must be delivered and Paint peeling from steel windows, doors, and storage. stored in the site with full coordination with steel parts Poor handling of wall surface (execution) supervisor and prior approval must be taken Improper link between coating type and from supervisor, and Paint analysis test and location . certificate of validity of compliance with Moisture and dampness or water leakage. local standards Improper or expired date of materials. External walls should be treated from cracks Quality of material. and holes by using Special pastes and all Fraud in painting . external paints should be moister resistance to Vandalism and culture of end user . aggressive weather. using new cover materials decrease maintenance work (Gargamish paint ) 2. Plumbing and sanitary (leaks in water Bad quality of materials used. Inspection and examination of pipe system supply and sewer systems) Execution procedures. before casting or covering under supervision Poor design (slope, diameter, locations) of mechanical engineer . Unintended mistakes. The contractor should carry out all the Lack of periodic inspection. required tests (pressure and hydraulic water Negligence of required tests . pressure tests . The contractor should provide evidence that equipment has passed the manufacture 's OC tests. procedure in site, approval of sample, and plane for supplied materials. selection specialist design engineers.
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Continue - Table 5.6:Summary for type of defects/errors with possible causes and solution (case stuies)
Defects 3.security screen and balustrade
4. Door and lock system
5. Cracks Defects between walls and structural elements
Possible Causes
Solution strategies
Vandalism, bad usage from end user and culture of end user. Poor design. Poor in execution (fixation ) Fraud in work . Dampness in the bottom level of panel and frames. Poor design of door frame . Vandalism and culture of end user. Using of weak materials . Approved sample of lock and knob. Variation of thermal expansion characteristics between concrete and block. Week bond between block and concrete. Foundation settlement. Weaknesses caused by corrosion/deterioration of materials, weakness of plaster mortar. Improper curing. damage by accidents, or poor design/ construction,
Awareness of end user. Using durable materials . Make spot check. Regular painting.
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Awareness of end use.r Using durable materials (aluminum ). Make preventive maintenance. Clear design details. Approval of samples. Embassies using metal angles in plaster works. details design the infill between concrete and columns must be clear .
Continue - Table 5.6:Summary for type of defects with possible causes and solution (case studies)
Defects 6.Interior walls Dampness
Possible Causes
Solution strategies
Water leakage from plumbing works under the tiles. Dripping fixtures like basin, slow drains Poor finishing of external walls and windows lintel .
Awareness of end user . Using durable materials Make spot check . Regular painting.
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6. Chapter 6: Conclusions and Recommendations 6.1
Introduction
This chapter includes the conclusions and recommendations that would help in improve the performance of UNRWA school buildings maintenance in GS by minimizing the defects of design and construction phase to increase the lifespan of UNRWA schools buildings. The first objective of this study was to identify the main types and causes of defects/errors in design phase that affecting maintenance of UNRWA school buildings . The second objective was to identify the main types and causes of defects/errors in construction phase that affecting maintenance of UNRWA school buildings. The third objective was to study the effects of faulty design and construction to maintenance UNRWA construction building projects at Gaza Strip. The fourth objective was to propose recommendations for solving future maintenance problem related to the school buildings at Gaza Strip.
6.2
Conclusions
This part of the thesis concludes the main findings of the research per objective, based on the opinions of the respondents as follows: 6.2.1 Results related to objective 1 " To identify the main types and causes of defects/errors in design that affecting maintenance of UNRWA school buildings " The design stage is very important phase of the project. Special care should be taken since it has a vital effect on the amount of maintenance woke that will be needed after the building completed. In this study, forty one factors (41), which leading to defects/errors in design stage were identified. Lack of workshops to discuss construction problems between the design, supervision and implementation staff is the most important factor that leading to defects/errors in design stage, the second important factor is inadequate QA/QC programs during design stage, the third factor is Lack of auditing and archiving of approved as-built drawing documents electronically, then the forth factor is dependence on repetition and lack of updating. Selecting of exterior finishing and isolation material not relating to climatic condition was in the fifth
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important factors. Finally, the lowest five factors leading to defects/errors in design stage are, not specifying to the allowable load limits, inadequate concrete cover on structural elements, exceeding the allowable deflection limits, and inadequate experience and expertise to design concrete admixtures. 6.2.2 Results related to objective 2 "To identify the main types and causes of defects/errors in construction phase that affecting maintenance of UNRWA school buildings" A construction defects as a consequence of wrong decision is one of the most common causes of early deterioration. In this study, thirty nine (39) factors which leading to defects/errors in construction stage were identified. contract awarding on lowest bidders price is the most important factor that leading to defects/errors in construction stage, the second important factor is the damage due to the multi-use of formwork in the construction industry. Accelerate in execution to avoid delay and lack of quality is the third important factors. Insufficient testing procedures during preliminary of water feeding and sewerage networks in the fourth. Then in the fifth was applying of painting layers improperly. Finally, the lowest five factors leading to defects/errors in construction stage are, the use of new materials are not known and did not examine the details of their quality in construction before in the local market, inadequate quality performance and quantity of the equipment, use expired material, inaccuracy of dimensions and measurement, and misuse of equipment. 6.2.3 Results related to objective 3 . " To study the effects of faulty design and construction to maintenance UNRWA construction building projects at Gaza Strip." There are three (3) important effects on maintenance of UNRWA school buildings due to the design and construction defects identified earlier and these are: Increased maintenance works, Increased maintenance time/duration, and Increased maintenance budget.
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Figure 6.1: Effects of faulty design and construction on maintenance of UNRWA school buildings
As mentioned above in Figure 6.1, the three (3) most important effects are interrelated, where an increase in maintenance works would therefore sees increase in maintenance time/duration and budget. The same could be applied to maintenance time and budget. To put things into perspective, a building with numerous design and construction defects will inevitably necessitate a larger scope and volume of maintenance works. As a result, this would leads to an increase in maintenance time/duration where defects require longer duration to fix and an increase in maintenance budget where the finances needed to perform maintenance would increase in tandem with building defects as part of the cost for performing maintenance operation, buying materials and equipment's.
6.3 -
Recommendations The designer must take into account maintenance considerations during the design and supervision stages by choosing of durable materials which suitable for sever environmental conditions.
-
Increase the level of interest in the plumbing and sanitary works, insulation works as well as finishing works in school buildings in GS.
149
-
This research recommends that a strict quality assurance & quality control (QA/QC) program be implemented for the designer and contractor to insure they follow the latest economical and practical specifications.
-
It is recommended UNRWA to form quality control unit, which should implement all necessary tasks to achieve the main objectives by having regular visits, carrying out spot checking to various construction sites, raise reports, observation and recommendations to CICIP .
-
Coordination between design, construction, and maintenance branches/divisions should be seen in all aspects of project implementation cycle as much as we can, especially in approval of the material samples.
-
It is recommended that the UNRWA is to developing maintenance a standard checklist and drawing library of good practical details. The maintenance standard checklist considers the lessons-learned that arising from construction and maintenance filed, where it is considered as an important factors that causes maintenance problem.
-
It is recommended UNRWA to plan for workshops or training program for designers engineers, supervisor, and maintenance engineers to avoid maintenance problems, and increase the level of technology information about finishing materials and to improve the quality of plumbing and sanitary works.
-
It is recommended to provide data library and report of defects/errors for different types of UNRWA building projects in Gaza to be used as benchmarking references.
-
The designers should consider the feedback by the maintenance teams to reduce the repetition of maintenance work.
6.4 -
Further Recommended Studies This study focused mainly on the type of defects that appeared during design and construction stage of UNRWA schools buildings in Gaza strip. For future research, it is recommended that main defects types may be various in other type of buildings such as residential buildings, office buildings, hospitals, mosques, training centers,
150
universities, high rise buildings, etc. So, relevant studies should include such buildings in order to determine the preventions measures in such projects. -
It is recommended to make a study similar to this research, but on building's electrical and mechanical defects due to design and construction stage .
-
It is also recommended that, other important factors should be focused and linked with the appearance of defects in construction projects. The most important of these factors is vandalism, building's characteristic. These may be lead to minimize the building defects and to improve the quality of maintenance of the future buildings.
-
Applying this study to the infrastructure project and compare the obtained results and factors.
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UNRWA website (n.d.) Overview UNRWA: Establishment and Missions. Available from: http://www.unrwa.org/etemplate.php Accessed 1/03/02]. Weldon, J. 1998. Housing design and development. In: Balchin, P. & Rhoden, M. (eds). Housing: The essential foundations. London: Routledge , pp.154-208. Xaba, M. I. (2012). A qualitative analysis of facilities maintenance-a school governance function in South Africa. South African Journal of Education, 32(2), 215-226. Zainal Abidin, A., Sharifah Hamimah, S., Ismail, A. R., & Maizam, A. (2009). School building maintenance strategy: A new management approach. Zainol, N. N., Woon, N. B., Ramli, N. A., & Mohammad, I. S. (2013). Barriers of Implementing Green Building Maintenance: A Preliminary Survey. In Proceeding of the Global Conference on Business, Economics and Social Sciences (pp. 425436). Ziara, M., Naser, K., & Touqan, S. (1997). Evaluation of Housing Affordability and Condition in Palestine. Final Report on Grant by the Swedish Government-Sida, Birzeit University, Palestine.. Zietsman, R. 2008. Defects in the South African construction industry now and then. In: Proceedings of the Construction Industry Development Board (CIDB) 5th Post-graduate Conference on Construction Industry Development, 16-18 March, Bloemfontein ، South Africa, pp. 108-114
158
ANNEX 1: QUESTIONNAIRE IN ENGLISH
The Islamic university of Gaza Higher Education Deanship Faculty of engineering Civil Engineering department Construction projects Management
اﻟﺟﺎﻣﻌﺔ اﻹﺳﻼﻣﯾﺔ – ﻏزة ﻋﻣﺎدة اﻟدراﺳﺎت اﻟﻌﻠﯾﺎ ﻛﻠﯾﺔ اﻟﮭﻧدﺳﺔ ﻗﺳم اﻟﮭﻧدﺳﺔ اﻟﻣدﻧﯾﺔ إدارة اﻟﻣﺷﺎرﯾﻊ اﻟﮭﻧدﺳﯾﺔ
Questionnaire for The effects of faulty/errors design and construction on UNRWA school buildings maintenance in Gaza strip Dear Sir / Madam Please fill in the required information in the attached questionnaire that aims to understand the effect of faulty design and construction on UNRWA school buildings maintenance in Gaza strip regarding the following issues:
1.
Types of defects/errors affecting maintenance of UNRWA school buildings in design stage at Gaza strip. 2. Types of defects/errors affecting maintenance of UNRWA school buildings in construction stage at Gaza strip. 3. Effects of faulty design and construction to maintenance UNRWA school building projects at Gaza Strip 4. The suggestion and strategies for solving future maintenance problem related to the school buildings This Research is part of the Master Study in the field of Construction Management at the Islamic University, for the researcher Eng./ Fathi Abu Sabha under the supervision on Dr.Khalid Al HALAQ and. Dr. Bassam Tayeh I appreciate your effort in answering the questions in the questionnaire, knowing that the given information will be used for the purpose of the scientific study only and will be treated confidentially. Thank you for your cooperation. Researcher Eng./ Fathi Abu Sabha November 2014 For any questions, please call Mobile No.: 0599461646, Email:
[email protected]
159
Section One: Respondents' general information 1.1 Type of Organization □ UNRWA Engineers
□ maintenance contractor
□ Other
1.2 Experience of the organization in maintenance work . □ less than 5 years □ (5- less 10) years □ ( 10- less15) years □ (15 and above) years 1.3 organization size (number of employees ) □ from(1-4)
□ from (5-20)
□ more than 20
1.4 Value of projects implemented during the last five years (Million Dollars) □ less than 5
□ from 5 to less than 10 □ from 10 to less than 15 □ 15 and above .
1.5 Job title of the person filling the questionnaire : □ Company Owner □ Project Manager □ Maintenance Engineer □ Other
□ Site/Office Eng.
□ Design Engineer
1.6 Education level of the person filling the questionnaire : □ Board examination exam (Tawjihi) or less
□ Diploma
□ Bachelor
□ Postgraduate Studies 1.7 years of experience of the person filling the questionnaire in maintenance work . □ (less than 3) years □ (5 –less than 10) years
□ (3 – less than 5) years □ (10 and above ) years
1.8 Gained qualification of the person filling the questionnaire : □ Experience
□ tertiary education
□ on – job training
160
□ Other
Section two : Defects/Errors in design stage affecting maintenance of UNRWA school buildings at Gaza strip Please tick (X) and select the appropriate item that you Strongly Agree (SA), AGree (AG), DisAgree (DA), Strongly Disagree (SD), Don't Know (DK) the statements as below:
# DK
Defects/Errors group 1
Defects in civil design
1.1
Ignore design of expansion / contraction / settlement joint and special construction joint Ignore the effects of the environment and the loads on structural elements and weather conditions on the materials used Using of type of foundations inappropriate to soil characteristics Ignore the difference in the adjacent soil layers and variation in soil conditions Ignore prepare soil tests in the projects and the depending on previous experience Ignoring the dynamic loads effects on the stability of the building (elevators, air conditioners and generators) Exceeding the allowable deflection limits Ignoring the design for wind effects and design for earthquakes loads effects on the structure Inadequate concrete cover on structural elements
1.2
1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11
Improperly locating conduits and pipe openings at critical structural locations (sleeves) Lack of attention to the design details and the concrete block walls and the intersection with the structural elements
2
Defects in architectural design
2.1
Designing narrow stairs, passage and doors that obstruct the transfer of equipment and maintenance work process Selecting of exterior finishing material not relating to climatic condition Ignore the effect of local weather conditions at the building site for the design of the external shapes Designing inadequate expansions joint which don't lead to required purpose between finished faces ,ceiling and wall Architectural design not integrated with the other project drawings Unclearness of architectural detail design
2.2 2.3 2.4
2.5 2.6
161
Application Degree SD DA AG
SA
# DK
Defects/Errors group 3
Defects due to owner firm administration and his staff
3.1 3.2
Inadequate (QA/QC) programs during design stage Lack of technical updating and adequate training of staff and lack of awareness of construction technology The lack of clarity and integrity and to provide full information to the designer by the owner Lack of adequate budget for maintenance work Lack of technical background and experience of the designer Ignore the designer to the properties, characteristics and behaviors of materials Misjudgment of environmental and climatic conditions Lack of documentation and archiving of the previous maintenance Poor communication between the design team and the crew of maintenance / implementation lack of workshops to discuss construction problems between the design, supervision and implementation Not be assigned to the engineer designing the parts that belonged to Staff pressure to accomplish works times less than the required period
3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12
4
Defects due drawings
4.1 4.2
Lack of references (cross sections and detailed) Conflicts of architectural and civil drawings
4.3
Poor and inaccurate details (detailed sections)
4.4
Lack of auditing and archiving of approved as-built drawing documents electronically dependence on repetition and lack of updating
4.5
5
Defects due specification
5.1
The specification is unclear and unrealistic
5.2
Not specifying to appropriate materials and specifications Not specifying quality assurance & quality control procedures (QA/QC) Not specifying to the allowable load limits
5.3 5.4 5.5 5.6 5.7
Inadequate experience and expertise to design concrete admixtures Absence of laws to building maintenance items and specifications (manual or code) Lack of local specifications and standards related of requirements of materials and workmanship
162
Application Degree SD DA AG
SA
Section three : Defects/Errors in construction stage affecting maintenance of UNRWA school buildings at Gaza strip .
# DK
Defects/Errors group
Application Degree SD DA AG SA
1
Defects due to lack of periodic checking and monitoring of construction
1.1 1.2
Lack of periodic inspection and monitoring
1.3 1.4
1.5
Lack of experience and qualification of inspector Ignore of owner monitoring and checking importance Weakness of inspection rule in implementing corrective actions during construction and not to give full powers to the inspector Insufficient testing procedures during preliminary of water feeding and sewerage
2
Defects due contractor administration and his staff
2.1 2.2 2.3
Non-compliance with specifications The contractor engineer not resident fully in the site Lack of contractor communication with the designer and owner Lack of efficiency and expertise of the contractor engineers and inability to read drawing
2.4 2.5
Accelerate in execution to avoid delay and lack of quality
2.6 2.7
2.8
Lack of workers experience and bad workmanship Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards. contract awarding on lowest bidders price
3
Defects due civil and architecture construction
3.1
Inaccuracy of dimensions and measurement
3.2 3.3
Lack of soil compaction Excavations with mechanical excavations tools near the existing building: The damage due to the multi-use of formwork in the construction industry insufficient applying of painting layers improperly
3.4 3.5 3.6 3.7 3.8
Inadequate insulation against water and sanitary works
3.9
Weakness contiguity and coherence between materials
3.10
Remove framework of concrete early before the time allowed Inadequate curing the casted parts well
3.11
Inadequate concrete cover for reinforced concrete Cold spacers between the new and old concrete
163
Application Degree
# DK
Defects/Errors group
3.12
Lack of sufficient vibration
3.13
Weakness and lack of homogeneity of concrete mix component or lack of compliance with the specifications components (in case of casting at the site)
4
Defects due to construction equipment
4.1
Misuse of equipment Inadequate quality performance and quantity of the equipment The lack of the required spare parts elements of the equipment Not taking into mind the availability of the equipment used in the maintenance in the local market during implementing The negligence of the periodic maintenance of the equipment
4.2 4.3 4.4
4.5
5
Defects due to construction materials
5.1
Selection of material that is unsuitable for existing climatic conditions Ignore the basic physical and chemical properties of materials use of non-durable materials (which does not stand up)
5.2 5.3 5.4 5.5
5.6 5.7 5.8
Use expired material The use of new materials are not known and did not examine the details of their quality in construction before in the local market Choice of substandard materials that have a poor quality of specifications Ignore determine the time and duration of storage and handling of materials and choosing the appropriate places Selection of cheap finishing materials price due to lack of fund
164
SD
DA
AG
SA
Section four : Effects of faulty design and construction to maintenance UNRWA school building projects at Gaza Strip. Please tick (X) and select the appropriate item that you Strongly Agree (SA), AGree (AG), DisAgree (DA), Strongly Disagree (SD), Don't Know (DK) the statements as below: Application Degree # Effects of faulty on maintenance DK SD DA AG SA
3.1 3.2 3.3 3.4 3.5
Increase in maintenance budget Increase in maintenance workforce Increase in maintenance works Increase in maintenance time\duration Lower maintenance quality
3.6
Difficulty in maintenance planning
3.7
Increased maintenance frequency
3.8
Decreased building age
Thank you for your cooperation
165
ANNEX 2: QUESTIONNAIRE IN ARABIC
The Islamic university of Gaza Higher Education Deanship Faculty of engineering Civil Engineering department Construction projects Management
اﻟﺟﺎﻣﻌﺔ اﻹﺳﻼﻣﯾﺔ – ﻏزة ﻋﻣﺎدة اﻟدراﺳﺎت اﻟﻌﻠﯾﺎ ﻛﻠﯾﺔ اﻟﮭﻧدﺳﺔ ﻗﺳم اﻟﮭﻧدﺳﺔ اﻟﻣدﻧﯾﺔ إدارة اﻟﻣﺷﺎرﯾﻊ اﻟﮭﻧدﺳﯾﺔ
اﺳﺗﺑﺎﻧﮫ ﺣول دراﺳﺔ ﺗﺄﺛﯿﺮ اﻷﺧﻄﺎء واﻟﻌﯿﻮب اﻟﺘﺼﻤﯿﻤﯿﺔ واﻟﺘﻨﻔﯿﺬﯾﺔ ﻋﻠﻰ ﺻﯿﺎﻧﺔ ﻣﺒﺎﻧﻲ ﻣﺪارس اﻻوﻧﺮوا ﻓﻲ ﻗﻄﺎع ﻏﺰة اﻟﺳﯾد /اﻟﺳﯾدة ﯾرﺟﻰ ﻣلء اﻟﻣﻌﻠوﻣﺎت اﻟﻣطﻠوﺑﺔ ﻓﻲ اﻻﺳﺗﺑﺎﻧﺔ اﻟﻣرﻓﻘﺔ واﻟﺗﻲ ﺗﮭدف إﻟﻰ ﺗﺣﺳﯾن اداء اﻟﺻﯾﺎﻧﺔ ﻓﻲ ﻣدارس ااﻷوﻧروا ﻓﻲ ﻗطﺎع ﻏزة ﻓﯾﻣﺎ ﯾﺗﻌﻠق ﺑﺎﻟﻘﺿﺎﯾﺎ اﻟﺗﺎﻟﯾﺔ : -١ -٢ -٣ -٤
اﻷﺧطﺎء/اﻟﻌﯾوب اﻟﺗﻲ ﺗﺣدث ﻓﻲ ﻣرﺣﻠﺔ اﻟﺗﺻﻣﯾم و اﻟﺗﻲ ﺗؤﺛر ﻋﻠﻰ ﺻﯾﺎﻧﺔ ﻣدارس اﻷوﻧروا ﻓﻲ ﻗطﺎع ﻏزة اﻷﺧطﺎء/اﻟﻌﯾوب اﻟﺗﻲ ﺗﺣدث ﻓﻲ ﻣرﺣﻠﺔ اﻟﺗﻧﻔﯾذ واﻟﺗﻲ ﺗؤﺛر ﻋﻠﻰ ﺻﯾﺎﻧﺔ ﻣدارس اﻷوﻧروا ﻓﻲ ﻗطﺎع ﻏزة ﺗﺄﺗﯾر اﻟﺗﺻﻣﯾم واﻟﺗﻧﻔﯾذ اﻟﺧﺎطﺊ ﻋﻠﻰ ﺻﯾﺎﻧﺔ ﻣﺷﺎرﯾﻊ ﻣدارس اﻻوﻧروا ﻓﻲ ﻗطﺎع ﻏزة ﺗﻘدﯾم اﻻﻗﺗراﺣﺎت واﻻﺳﺗراﺗﯾﺟﯾﺎت ﻟﺣل اﻟﻣﺷﺎﻛل اﻟﻣﺳﺗﻘﺑﻠﯾﺔ اﻟﻣﺗﻌﻠﻘﺔ ﺑﺻﯾﺎﻧﺔ ﻣدارس اﻻوﻧروا
ﻋﻠﻣﺎ ﺑﺄن ھذه اﻟدراﺳﺔ ھﻲ ﺟزء ﻣن اﻟﺑﺣث اﻟﺗﻛﻣﯾﻠﻲ ﻟﻧﯾل درﺟﺔ اﻟﻣﺎﺟﺳﺗﯾر ﻓﻲ إدارة اﻟﻣﺷﺎرﯾﻊ اﻟﮭﻧدﺳﯾﺔ ﻓﻲ اﻟﺟﺎﻣﻌﺔ اﻹﺳﻼﻣﯾﺔ ﻟﻠﺑﺎﺣث اﻟﻣﮭﻧدس /ﻓﺗﺣﻲ ﺣﺳن أﺑو ﺻﺑﺣﮫ ﺗﺣت اﺷراف ﻛﻼ ﻣن اﻟدﻛﺗور ﺧﺎﻟد اﻟﺣﻼق واﻟدﻛﺗور ﺑﺳﺎم ﺗﺎﯾﮫ. ﻛﻣﺎ ﯾرﺟﻰ ﻣن ﺳﯾﺎدﺗﻛم اﻻﺟﺎﺑﺔ ﻋﻠﻰ ﺟﻣﯾﻊ اﻻﺳﺋﻠﺔ ﻣﺎ اﻣﻛن .ﻛﻣﺎ ﯾﻣﻛن اﺿﺎﻓﺔ ﻋواﻣل اﺧرى ان ﻛﺎﻧت ﺿرورﯾﺔ او اﺿف اﻟﺗﻌﻠﯾق اﻟﻣﻧﺎﺳب ﻋﻧد اﻟﻠزوم . وإﻧﻧﻲ أﺛﻣن ﺟﮭدﻛم وإﺟﺎﺑﺎﺗﻛم ﻋﻠﻰ اﻷﺳﺋﻠﺔ اﻟﻣطروﺣﺔ ﻓﻲ اﻻﺳﺗﺑﯾﺎن ﻋﻠﻣﺎ ﺑﺎن ﺟﻣﯾﻊ اﻟﻣﻌﻠوﻣﺎت اﻟﺗﻲ ﯾﺗم اﻟﺣﺻول ﻋﻠﯾﮭﺎ ﻣن ﺳﯾﺎدﺗﻛم ﺳوف ﺗﺳﺗﺧدم ﻟﻐرض اﻟدراﺳﺔ اﻟﻌﻠﻣﯾﺔ اﻟﺑﺣﺗﺔ ﺑﮭدف اﻟﺗطوﯾر وﺳوف ﺗﻌﺎﻣل ﺑﺳرﯾﺔ . أﺷﻛر ﺳﯾﺎدﺗﻛم ﻋﻠﻰ اﻟﺗﻌﺎون وﺗﻘﺑﻠوا ﻓﺎﺋق اﻻﺣﺗرام واﻟﺗﻘدﯾر اﻟﺑﺎﺣث :م ﻓﺗﺣﻲ ﺣﺳن أﺑو ﺻﺑﺣﮫ ﻧوﻓﻣﺑر 2014 )ﻟﻼﺳﺗﻔﺳﺎر ﯾﻣﻛن اﻻﺗﺻﺎل ﻋﻠﻰ اﻟﺟوال f.abu- ،
[email protected] ، 0599461646/ (
[email protected]
166
اﻟﺠﺰء اﻷول :ﻣﻌﻠﻮﻣﺎت ﻋﺎﻣﺔ ﺑﺎﻟﺠﮭﺔ اﻟﻤﺴﺘﮭﺪﻓﺔ 1.1طﺑﯾﻌﺔ اﻟﻌﻣل □ ﻗﺴﻢ اﻟﮭﻨﺪﺳﺔ ﺑﺎﻻوﻧﺮوا □ ﻣﻘﺎول ﺻﯿﺎﻧﺔ ﺑﺎﻷوﻧﺮوا □ ﻏﯿﺮ ذﻟﻚ 1.2ﺧﺑرة اﻟﻣؤﺳﺳﺔ ﻓﻲ اﻋﻣﺎل اﻟﺻﯾﺎﻧﺔ □ اﻗﻞ ﻣﻦ 5ﺳﻨﻮات □ ﻣﻦ ) -5اﻗﻞ ( 10ﺳﻨﻮات □ ﻣﻦ ) -10اﻗﻞ ( 15ﺳﻨﺔ □ 15ﺳﻨﺔ ﻓﺄﻛﺜﺮ 1.3ﺣﺟم اﻟﻣؤﺳﺳﺔ ) ﻋدد اﻟﻣوظﻔﯾن ( □ ﻣﻦ )( 4-1
□ ﻣﻦ )(20 - 5
□ اﻛﺜﺮ ﻣﻦ 20
1.4ﻗﯾﻣﺔ اﻟﻣﺷﺎرﯾﻊ اﻟﻣﻧﻔذة ﺧﻼل آﺧر ﺧﻣس ﺳﻧوات )ﻣﻠﯾون دوﻻر( □ اﻗﻞ ﻣﻦ5
□ ﻣﻦ ) - 5اﻗﻞ ﻣﻦ (10
□ ﻣﻦ ) - 10اﻗﻞ ﻣﻦ 15 □ ( 15ﻓﺄﻛﺜﺮ
1.5اﻟوظﯾﻔﺔ اﻹدارﯾﺔ ﻟﻣﺎﻟﺊ اﻻﺳﺗﺑﺎﻧﺔ □ﺻﺎﺣﺐ ﺷﺮﻛﺔ
□ﻣﺪﯾﺮ ﻣﺸﺮوع
□ ﻣﮭﻨﺪس ﻣﻜﺘﺐ/ﻣﻮﻗﻊ
□ﻣﮭﻨﺪس ﺗﺼﻤﯿﻢ
□ﻣﮭﻨﺪس ﺻﯿﺎﻧﺔ 1.6اﻟﻣﺳﺗوى اﻟﺗﻌﻠﯾﻣﻲ ﻟﻣﺎﻟﺊ اﻻﺳﺗﺑﺎﻧﺔ □ﺗﻮﺟﯿﮭﻲ ﻓﺎﻗﻞ
□ دﺑﻠﻮم
□ﺑﻜﺎﻟﻮرﯾﻮس
□ دراﺳﺎت ﻋﻠﯿﺎ )ﻣﺎﺟﺴﺘﯿﺮ أو دﻛﺘﻮراه (
1.7ﻋدد ﺳﻧوات ﺧﺑرة ﻟﻣﺎﻟﺊ اﻻﺳﺗﺑﺎﻧﺔ ﻓﻲ أﻋﻣﺎل اﻟﺻﯾﺎﻧﺔ □)اﻗﻞ ﻣﻦ (3ﺳﻨﻮات □ )-3ﻷﻗﻞ ﻣﻦ ( 5ﺳﻨﻮات □ )-5ﻷﻗﻞ ﻣﻦ ( 10ﺳﻨﻮات □ 10ﺳﻨﻮات ﻓﺄﻛﺜﺮ 1.8ﺳﺑل اﻛﺗﺳﺎب اﻟﻛﻔﺎءة ﻟﺷﺧص ﻣﺎﻟﺊ اﻻﺳﺗﺑﺎﻧﺔ ﻓﻲ أﻋﻣﺎل اﻟﺻﯾﺎﻧﺔ □اﻟﺨﺒﺮة
□اﻟﺘﻌﻠﯿﻢ
□اﻟﺘﺪرﯾﺐ
167
□ ﻏﯿﺮ ذﻟﻚ
اﻟﺠﺰء اﻟﺜﺎﻧﻲ :اﻟﻌﯿﻮب /اﻷﺧﻄﺎء اﻟﺘﻲ ﺗﺤﺪث ﻓﻲ ﻣﺮﺣﻠﺔ اﻟﺘﺼﻤﯿﻢ و ﺗﺆﺛﺮ ﻋﻠﻰ ﺻﯿﺎﻧﺔ اﻟﻤﺒﺎﻧﻲ اﻟﻤﺪرﺳﯿﺔ ﺑﻮﻛﺎﻟﺔ اﻟﻐﻮث ﻓﻲ ﻗﻄﺎع ﻏﺰة اﻟﺮﺟﺎء وﺿﻊ إﺷﺎرة ) (Xواﺧﺘﯿﺎر اﻟﺪرﺟﺔ اﻟﻤﻨﺎﺳﺒﺔ ﻟﻜﻞ ﻣﻦ اﻟﻌﺒﺎرات اﻟﺘﺎﻟﯿﺔ: درﺟﺔ اﻟﺘﻄﺒﯿﻖ
1.5 1.6 1.7 1.8 1.9 1.10 1.11 2 2.1 2.2 2.3 2.4 2.5 2.6
ﻻ أواﻓﻖ ﺑﺸﺪة
1.3 1.4
168
اﺣﯿﺎﻧﺎ
1.2
أواﻓﻖ
1.1
ﺗﺠﺎھﻞ ﺗﺼﻤﯿﻢ ﻓﻮاﺻﻞ ﺗﻤﺪد /اﻧﻜﻤﺎش/ھﺒﻮط و ﻓﻮاﺻﻞ اﻧﺸﺎﺋﯿﺔ ﺧﺎﺻﺔ ﺗﺠﺎھﻞ ﺗﺄﺛﯿﺮات اﻟﺒﯿﺌﺔ وأﺣﻤﺎﻟﮭﺎ ﻋﻠﻰ اﻟﻌﻨﺎﺻﺮ اﻹﻧﺸﺎﺋﯿﺔ وظﺮوف اﻟﻄﻘﺲ واﻟﻤﻨﺎخ ﻟﻠﻤﻮاد اﻟﻤﺴﺘﺨﺪﻣﺔ اﺳﺘﺨﺪام أﻧﻮاع ﻗﻮاﻋﺪ ﻏﯿﺮ ﻣﻨﺎﺳﺒﺔ ﻟﺨﺼﺎﺋﺺ اﻟﺘﺮﺑﺔ ﺗﺠﺎھﻞ اﻻﺧﺘﻼف ﻓﻲ طﺒﻘﺎت اﻟﺘﺮﺑﺔ اﻟﻤﺠﺎورة ﺗﺠﺎھﻞ ﻋﻤﻞ ﻓﺤﺺ ﻟﻠﺘﺮﺑﺔ ﺑﺎﻟﻤﺸﺮوع واﻻﻋﺘﻤﺎد ﻋﻠﻰ اﻟﺨﺒﺮات اﻟﺴﺎﺑﻘﺔ ﺗﺠﺎھﻞ ﺗﺄﺛﯿﺮ اﻷﺣﻤﺎل اﻟﺪﯾﻨﺎﻣﯿﻜﯿﺔ ﻋﻠﻰ اﺗﺰان اﻟﻤﺒﻨﻰ )اﻟﻤﺼﺎﻋﺪ واﻟﻤﻜﯿﻔﺎت واﻟﻤﻮﻟﺪات ( ﺗﺠﺎوز اﻻﻧﺤﻨﺎء اﻟﻤﺴﻤﻮح ﺑﮫ )(Deflection ﺗﺠﺎھﻞ أو ﻗﺼﻮر ﺗﺼﻤﯿﻢ ﺗﺄﺛﯿﺮ ﻗﻮى اﻟﺮﯾﺎح ﻋﻠﻰ اﻟﻤﻨﺸﺄ وأﺣﻤﺎل اﻟﺰﻻزل . ﻋﺪم وﺟﻮد ﻏﻄﺎء ﺧﺮﺳﺎﻧﻲ ﻛﺎﻓﻲ ﻓﻲ اﻟﻌﻨﺎﺻﺮ اﻟﺨﺮﺳﺎﻧﯿﺔ ﻋﺪم اﺧﺘﯿﺎر اﻷﻣﺎﻛﻦ اﻟﻤﻨﺎﺳﺒﺔ ﻟﻔﺘﺤﺎت اﻟﻤﻮاﺳﯿﺮ ﻓﻲ اﻷﻣﺎﻛﻦ اﻟﺤﺮﺟﺔ ﻓﻲ اﻟﻤﻨﺸﺄ )(Sleeves ﻋﺪم اﻻھﺘﻤﺎم ﺑﺘﺼﻤﯿﻢ وﺗﻔﺎﺻﯿﻞ ﺣﻮاﺋﻂ اﻟﺒﻠﻮك اﻻﺳﻤﻨﺘﻲ وﺗﻘﺎطﻌﮭﺎ ﻣﻊ اﻟﻌﻨﺎﺻﺮ اﻹﻧﺸﺎﺋﯿﺔ ﻋﯿﻮب ﻓﻲ اﻟﺘﺼﻤﯿﻢ اﻟﻤﻌﻤﺎري ﺗﺼﻤﯿﻢ اﻟﺴﻼﻟﻢ واﻟﻤﻤﺮات واﻷﺑﻮاب اﻟﻀﯿﻘﺔ اﻟﺘﻲ ﺗﻌﺮﻗﻞ ﻋﻤﻠﯿﺔ ﻧﻘﻞ اﻟﻤﻌﺪات واﻟﻘﯿﺎم ﺑﺄﻋﻤﺎل اﻟﺼﯿﺎﻧﺔ ﻋﺪم اﺧﺘﯿﺎر ﻣﻮاد اﻟﻌﺰل اﻟﺨﺎرﺟﯿﺔ اﻟﻤﻨﺎﺳﺒﺔ )دھﺎن ﻻ ﯾﻘﺎوم اﻟﺮطﻮﺑﺔ واﻟﺤﺮارة( ﺗﺠﺎھﻞ ﺗﺄﺛﯿﺮ اﻟﻈﺮوف اﻟﻤﻨﺎﺧﯿﺔ اﻟﻤﺤﻠﯿﺔ ﻟﻤﻮﻗﻊ اﻟﻤﺒﻨﻰ ﻋﻨﺪ ﺗﺼﻤﯿﻢ اﻷﺷﻜﺎل اﻟﺨﺎرﺟﯿﺔ ﻛﺎﻟﻘﺮب ﻣﻦ اﻟﻤﻨﺎطﻖ اﻟﺴﺎﺣﻠﯿﺔ وﺗﺄﺛﯿﺮھﺎ ﻋﻠﻰ اﻟﻤﺒﺎﻧﻲ واﻟﺘﺸﻄﯿﺒﺎت اﻟﺨﺎرﺟﯿﺔ وأﻧﻮاع اﻟﺤﺪﯾﺪ اﺳﺘﺨﺪام ﻓﻮاﺻﻞ ﺗﻤﺪد ﻏﯿﺮ ﻛﺎﻓﯿﺔ وﻻ ﺗﺆدي اﻟﻐﺮض اﻟﻤﻄﻠﻮب ﺑﯿﻦ اﻷوﺟﮫ اﻟﻤﺸﻄﺒﺔ أو اﻷﺳﻘﻒ واﻟﺤﻮاﺋﻂ . ﻋﺪم ﺗﻜﺎﻣﻞ اﻟﺘﺼﻤﯿﻢ اﻟﻤﻌﻤﺎري ﻣﻊ ﺑﺎﻗﻲ ﻣﺨﻄﻄﺎت اﻟﻤﺸﺮوع ﻋﺪم وﺿﻮح اﻟﺘﻔﺎﺻﯿﻞ اﻟﻤﻌﻤﺎرﯾﺔ اﻟﺘﺼﻤﯿﻤﯿﺔ ﻛﻌﺰل اﻻﺳﻘﻒ
أواﻓﻖ ﺑﺸﺪة
1
ﻋﯿﻮب ﻓﻲ اﻟﺘﺼﻤﯿﻢ اﻹﻧﺸﺎﺋﻲ
ﻻ أواﻓﻖ
م
ﻣﺠﻤﻮﻋﺎت اﻟﻌﯿﻮب واﻷﺧﻄﺎء
درﺟﺔ اﻟﺘﻄﺒﯿﻖ
3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 4 4.1 4.2 4.3 4.4 4.5 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7
ﻻ أواﻓﻖ ﺑﺸﺪة
3.3
169
اﺣﯿﺎﻧﺎ
3.2
أواﻓﻖ
3.1
ﻧﻘﺺ ﺑﺮاﻣﺞ ﺗﺄﻛﯿﺪ اﻟﺠﻮدة واﻟﺘﺤﻜﻢ ﺑﮭﺎ ﺧﻼل اﻟﺘﺼﻤﯿﻢ ﻧﻘﺺ اﻟﺘﺤﺪﯾﺚ اﻟﻔﻨﻲ واﻟﺘﺪرﯾﺐ اﻟﻜﺎﻓﻲ ﻟﻠﻤﻮظﻔﯿﻦ وﻋﺪم اﻟﻮﻋﻲ ﺑﺘﻜﻨﻮﻟﻮﺟﯿﺎ اﻟﺒﻨﺎء ﻋﺪم وﺿﻮح وﺗﻜﺎﻣﻞ و ﺗﻮﻓﯿﺮ اﻟﻤﻌﻠﻮﻣﺎت اﻟﻜﺎﻣﻠﺔ ﻟﻠﻤﺼﻤﻢ ﻣﻦ ﻗﺒﻞ اﻟﻤﺎﻟﻚ ﻋﺪم وﺟﻮد ﻣﯿﺰاﻧﯿﺔ ﻛﺎﻓﯿﺔ ﻷﻋﻤﺎل اﻟﺼﯿﺎﻧﺔ ﻧﻘﺺ اﻟﺨﻠﻔﯿﺔ اﻟﻔﻨﯿﺔ ﻟﻠﻤﺼﻤﻢ وﻛﺬﻟﻚ اﻟﺨﺒﺮة ﺗﺠﺎھﻞ اﻟﻤﺼﻤﻢ ﻟﺨﻮاص وﺧﺼﺎﺋﺺ وﺗﺼﺮف اﻟﻤﻮاد ﺳﻮء اﻟﺘﻘﺪﯾﺮ ﻟﻠﻈﺮوف اﻟﺒﯿﺌﯿﺔ اﻟﻤﺤﯿﻄﺔ ﻟﻠﻤﺠﺎري واﻟﺼﺮف ﻧﻘﺺ اﻟﺘﻮﺛﯿﻖ واﻷرﺷﻔﺔ ﻷﻋﻤﺎل اﻟﺼﯿﺎﻧﺔ اﻟﺴﺎﺑﻘﺔ ﺿﻌﻒ اﻟﺘﻮاﺻﻞ ﺑﯿﻦ ﻓﺮﯾﻖ اﻟﺘﺼﻤﯿﻢ وطﺎﻗﻢ اﻟﺼﯿﺎﻧﺔ/اﻟﺘﻨﻔﯿﺬ ﻧﻘﺺ ﻋﻤﻞ ورﺷﺎت ﻋﻤﻞ ﻟﻤﻨﺎﻗﺸﺔ ﻣﺸﺎﻛﻞ اﻟﺘﻨﻔﯿﺬ ﺑﯿﻦ اﻟﺘﺼﻤﯿﻢ واﻹﺷﺮاف واﻟﺘﻨﻔﯿﺬ ﻋﺪم ﺗﻜﻠﯿﻒ اﻟﻤﮭﻨﺪس اﻟﻤﺨﺘﺺ ﺑﺘﺼﻤﯿﻢ اﻻﺟﺰاء اﻟﺘﻲ ﺗﺨﺼﮫ ﺿﻐﻂ اﻟﻤﻮظﻔﯿﻦ ﻹﻧﺠﺎز اﻻﻋﻤﺎل ﺑﺄوﻗﺎت اﻗﻞ ﻣﻦ اﻟﻤﺪة اﻟﻤﻄﻠﻮﺑﺔ ﻋﯿﻮب ﺑﺴﺒﺐ اﻟﻤﺨﻄﻄﺎت ﻧﻘﺺ اﻟﻤﺮاﺟﻊ )ﻣﻘﺎطﻊ ﻋﺮﺿﯿﺔ وﺗﻔﺼﯿﻠﯿﺔ( ﺗﻀﺎرب اﻟﻤﺨﻄﻄﺎت اﻟﻤﻌﻤﺎرﯾﺔ واﻹﻧﺸﺎﺋﯿﺔ اﻟﺘﻔﺎﺻﯿﻞ ﻏﯿﺮ اﻟﺪﻗﯿﻘﺔ ) اﻟﻤﻘﺎطﻊ اﻟﻌﺮﺿﯿﺔ واﻟﺘﻔﺼﯿﻠﯿﺔ ( ﻋﺪم ﺗﻮﺛﯿﻖ وﺗﺪﻗﯿﻖ اﻟﻤﺨﻄﻄﺎت ﺑﻌﺪ اﻟﺘﻨﻔﯿﺬ اﻻﻋﺘﻤﺎد ﻋﻠﻰ اﻟﺘﻜﺮار وﻋﺪم اﻟﺘﺤﺪﯾﺚ ﻋﯿﻮب ﺑﺴﺒﺐ اﻟﻤﻮاﺻﻔﺎت ﻋﺪم وﺿﻮح اﻟﻤﻮاﺻﻔﺎت وﻋﺪم واﻗﻌﯿﺘﮭﺎ ﻻ ﯾﻮﺟﺪ ﺗﺤﺪﯾﺪ ﻟﻠﻤﻮاد اﻟﻤﻨﺎﺳﺒﺔ وﻣﻮاﺻﻔﺎﺗﮭﺎ ﻻ ﯾﻮﺟﺪ ﺗﺤﺪﯾﺪ ﻹﺟﺮاءات ﺿﺒﻂ اﻟﺠﻮدة وﺗﺄﻛﯿﺪھﺎ ﻻ ﯾﻮﺟﺪ ﺗﺤﺪﯾﺪ ﻟﺤﺪود اﻷﺣﻤﺎل اﻟﻤﺴﻤﻮح ﺑﮭﺎ ﻻ ﯾﻮﺟﺪ ﺧﺒﺮة ودراﯾﺔ ﻛﺎﻓﯿﺔ ﻟﺘﺼﻤﯿﻢ اﻟﺨﻠﻄﺎت اﻟﺨﺮﺳﺎﻧﯿﺔ ﻋﺪم وﺟﻮد ﻗﻮاﻧﯿﻦ ﻟﺒﻨﻮد اﻟﺼﯿﺎﻧﺔ وﻣﻮاﺻﻔﺎﺗﮭﺎ )ﻣﺎﻧﯿﻮل او ﻛﻮد ( ﻧﻘﺺ اﻟﻤﺮاﺟﻊ ﻟﺘﻮﺿﯿﺢ اﻟﻤﻮاﺻﻔﺎت اﻟﺤﺪﯾﺜﺔ واﻟﻤﻌﺎﯾﯿﺮ اﻟﻤﺤﻠﯿﺔ اﻟﺨﺎﺻﺔ ﺑﻤﺘﻄﻠﺒﺎت اﻟﻤﻮاد واﻟﻤﺼﻨﻌﯿﺔ
أواﻓﻖ ﺑﺸﺪة
3
ﻋﯿﻮب ﻧﺎﺗﺠﺔ ﻋﻦ إدارة ﻣﺆﺳﺴﺔ اﻟﻤﺎﻟﻚ
ﻻ أواﻓﻖ
م
ﻣﺠﻤﻮﻋﺎت اﻟﻌﯿﻮب واﻷﺧﻄﺎء
اﻟﺠﺰء اﻟﺜﺎﻟﺚ :اﻟﻌﯿﻮب /اﻷﺧﻄﺎء اﻟﺘﻲ ﺗﺤﺪث ﻓﻲ ﻣﺮﺣﻠﺔ اﻟﺘﻨﻔﯿﺬ و ﺗﺆﺛﺮ ﻋﻠﻰ ﺻﯿﺎﻧﺔ اﻟﻤﺒﺎﻧﻲ اﻟﻤﺪرﺳﯿﺔ ﺑﻮﻛﺎﻟﺔ اﻟﻐﻮث ﻓﻲ ﻗﻄﺎع ﻏﺰة درﺟﺔ اﻟﺘﻄﺒﯿﻖ
2.5 2.6 2.7 2.8 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13
ﻻ أواﻓﻖ ﺑﺸﺪة
2.4
170
اﺣﯿﺎﻧﺎ
1.5 2 2.1 2.2 2.3
أواﻓﻖ
1.4
أواﻓﻖ ﺑﺸﺪة
1 1.1 1.2 1.3
ﻋﯿﻮب ﺑﺴﺒﺐ ﻧﻘﺺ اﻟﻔﺤﺺ واﻟﺘﻔﺘﯿﺶ واﻟﻤﺮاﻗﺒﺔ اﻟﺪورﯾﺔ ﻟﻠﺘﺸﯿﯿﺪ ﻧﻘﺺ اﻟﺘﻔﺘﯿﺶ واﻟﻔﺤﺺ واﻟﻤﺮاﻗﺒﺔ اﻟﺪورﯾﺔ ) ﻏﯿﺮ ﻛﺎﻓﻲ( ﻗﻠﺔ ﺧﺒﺮة اﻟﻤﺮاﻗﺐ وﻋﺪم ﺗﺄھﯿﻠﮫ إھﻤﺎل أھﻤﯿﺔ اﻟﻤﺮاﻗﺒﺔ واﻟﻔﺤﺺ ﻣﻦ ﻗﺒﻞ اﻟﻤﺎﻟﻚ. ﺿﻌﻒ ﻗﻮاﻧﯿﻦ اﻟﻔﺤﺺ واﻟﻤﺮاﻗﺒﺔ ﻓﻲ اﺗﺨﺎذ اﻹﺟﺮاءات اﻟﺘﺼﺤﯿﺤﯿﺔ ﺧﻼل ﻋﻤﻠﯿﺔ اﻟﺘﻨﻔﯿﺬ وﻋﺪم إﻋﻄﺎء اﻟﺼﻼﺣﯿﺎت اﻟﻜﺎﻣﻠﺔ ﻟﻠﻤﻔﺘﺶ . ﻧﻘﺺ اﺟﺮاء اﻟﻔﺤﻮﺻﺎت اﺛﻨﺎء اﻋﻤﺎل اﻟﺘﺄﺳﯿﺲ اﻟﺼﺤﻲ ﻋﯿﻮب ﺑﺴﺒﺐ إدارة اﻟﻤﻘﺎول وطﺎﻗﻤﮫ ﻋﺪم اﻻﻟﺘﺰام ﺑﺎﻟﻤﻮاﺻﻔﺎت ﻋﺪم ﺗﻔﺮغ ﻣﮭﻨﺪس اﻟﻤﻘﺎول ﺑﺎﻟﻤﻮﻗﻊ ﺑﺸﻜﻞ ﻛﺎﻣﻞ ﻗﻠﺔ اﻟﺘﻮاﺻﻞ ﻣﻊ اﻟﻤﺼﻤﻢ واﻟﻤﺎﻟﻚ ﻧﻘﺺ ﻛﻔﺎءة وﺧﺒﺮات ﻣﮭﻨﺪﺳﻲ اﻟﻤﻘﺎول و ﻋﺪم اﻟﻘﺪرة ﻋﻠﻰ ﻗﺮاءة اﻟﻤﺨﻄﻄﺎت اﻟﺴﺮﻋﺔ ﻓﻲ اﻻﻧﺠﺎز ﻟﺘﻔﺎدي اﻟﺘﺄﺧﯿﺮ وﻗﻠﺔ ﺟﻮدة اﻟﻌﻤﻞ ﻧﻘﺺ ﺧﺒﺮة اﻟﻘﻮى اﻟﻌﺎﻣﻠﺔ وﺳﻮء ﻣﺼﻨﻌﺘﯿﮭﺎ ﺗﺪاﺧﻞ اﻋﻤﺎل اﻟﺘﺸﻄﯿﺐ ﺑﺸﻜﻞ ﻣﺘﺴﺎرع وﻣﺘﺘﺎﻟﻲ دون اﻋﻄﺎء ﻛﻞ ﻧﺸﺎط زﻣﻨﮫ اﻟﻜﺎﻓﻲ ﺣﺴﺐ اﻻﺻﻮل اﻟﮭﻨﺪﺳﯿﺔ ﺗﺮﺳﯿﮫ اﻟﻌﻄﺎءات ﻋﻠﻰ اﻗﻞ اﻻﺳﻌﺎر ﻋﯿﻮب ﺑﺴﺒﺐ اﻟﺘﺸﯿﯿﺪ اﻟﻤﻌﻤﺎري واﻹﻧﺸﺎﺋﻲ ﻋﺪم دﻗﺔ اﻟﻤﻘﺎﺳﺎت واﻷﺑﻌﺎد ﻋﺪم دﻣﻚ اﻟﺘﺮﺑﺔ ﺟﯿﺪا اﻟﺤﻔﺮﯾﺎت ﺑﺄدوات اﻟﺤﻔﺮ اﻟﻤﯿﻜﺎﻧﯿﻜﯿﮫ ﻗﺮب ﻣﺒﻨﻰ ﻗﺎﺋﻢ ﺗﻠﻒ وﻋﯿﻮب ﺑﻘﻮاﻟﺐ اﻟﻄﻮﺑﺎر ﻧﻈﺮا ﻟﻘﺪﻣﮭﺎ وﻋﺪم ﺗﺠﺪﯾﺪھﺎ وﺗﻌﺪد اﺳﺘﺨﺪاﻣﮭﺎ ﺗﻨﻔﯿﺬ اﻟﺪھﺎن ﺑﺸﻜﻞ ﻏﯿﺮﺻﺤﯿﺢ ﻋﺪم ﻛﻔﺎﯾﺔ اﻟﻌﺰل ﻟﻸﺳﻄﺢ اﻟﻨﮭﺎﺋﯿﺔ ﺿﺪ اﻟﻤﯿﺎه واﻟﺼﺮف اﻟﺼﺤﻲ ﻋﺪم ﻛﻔﺎﯾﺔ ﻏﻄﺎء ﺧﺮﺳﺎﻧﻲ ﻟﻠﺨﺮﺳﺎﻧﺔ اﻟﻤﺴﻠﺤﺔ اﺧﺘﯿﺎر اﻣﺎﻛﻦ ﻏﯿﺮ ﻣﻨﺎﺳﺒﺔ ﻟﻔﻮاﺻﻞ اﻟﺼﺐ وﻋﺪم اﻻھﺘﻤﺎم ﺑﻤﻌﺎﻟﺠﺔ ﻓﻮاﺻﻞ اﻟﺼﺐ ﺑﻄﺮﯾﻘﺔ ﺻﺤﯿﺤﺔ ﺿﻌﻒ اﻟﺘﻼﺻﻖ واﻟﺘﻤﺎﺳﻚ ﺑﯿﻦ اﻟﻤﻮاد )اﻟﺨﺮﺳﺎﻧﺔ واﻟﺒﻠﻮك( ﻓﻚ طﻮﺑﺎر اﻟﺒﺎطﻮن ﻣﺒﻜﺮا ﻗﺒﻞ اﻟﻮﻗﺖ اﻟﻤﺴﻤﻮح ﻋﺪم ﻣﻌﺎﻟﺠﺔ اﻷﺟﺰاء اﻟﻤﺼﺒﻮﺑﺔ ﺟﯿﺪا ﻋﺪم ﺗﻮﻓﺮ اﻟﺮج اﻟﻜﺎﻓﻲ ﻋﺪم ﺗﺠﺎﻧﺲ ﻣﻜﻮﻧﺎت اﻟﺨﻠﻂ وﺿﻌﻔﮭﺎ أو ﻋﺪم ﻣﻄﺎﺑﻘﺘﮭﺎ ﻟﻠﻤﻮاﺻﻔﺎت )ﻓﻲ ﺣﺎل اﻟﺨﻠﻂ ﻓﻲ اﻟﻤﻮﻗﻊ (
ﻻ أواﻓﻖ
م
ﻣﺠﻤﻮﻋﺎت اﻟﻌﯿﻮب واﻷﺧﻄﺎء
درﺟﺔ اﻟﺘﻄﺒﯿﻖ
5.6 5.7 5.8
ﻻ أواﻓﻖ ﺑﺸﺪة
5.5
ﻻ أواﻓﻖ
4.5 5 5.1 5.2 5.3 5.4
اﺣﯿﺎﻧﺎ
4.4
أواﻓﻖ
4 4.1 4.2 4.3
ﻋﯿﻮب ﺑﺴﺒﺐ ﻣﻌﺪات اﻹﻧﺸﺎء اﻻﺳﺘﺨﺪام اﻟﺴﯿﺊ واﻟﻐﯿﺮ ﺳﻠﯿﻢ ﻟﻠﻤﻌﺪات ﻋﺪم ﻛﻔﺎﯾﺔ وﺟﻮدة أداء اﻟﻤﻌﺪات ﻧﻘﺺ اﻟﻌﻨﺎﺻﺮ اﻟﻤﻄﻠﻮﺑﺔ ﻣﻦ اﻟﻤﻌﺪات ﻋﺪم اﻷﺧﺬ ﺑﻌﯿﻦ اﻻﻋﺘﺒﺎر ﺗﻮﻓﺮ اﻟﻤﻌﺪات اﻟﻤﺴﺘﺨﺪﻣﺔ ﻓﻲ اﻟﺼﯿﺎﻧﺔ ﻓﻲ اﻟﺴﻮق اﻟﻤﺤﻠﯿﺔ ﻋﻨﺪ اﻟﺘﻨﻔﯿﺬ اھﻤﺎل اﻟﺼﯿﺎﻧﺔ اﻟﺪورﯾﺔ ﻟﻠﻤﻌﺪات ﻋﯿﻮب ﺑﺴﺒﺐ ﻣﻮاد اﻹﻧﺸﺎء اﺧﺘﯿﺎر اﻟﻤﻮاد اﻟﻐﯿﺮ ﻣﻨﺎﺳﺒﺔ ﻟﻠﻈﺮوف اﻟﻤﻨﺎﺧﯿﺔ ﺗﺠﺎھﻞ ﺧﺼﺎﺋﺺ اﻟﻤﻮاد اﻟﻔﯿﺰﯾﺎﺋﯿﺔ واﻟﻜﯿﻤﯿﺎﺋﯿﺔ اﻷﺳﺎﺳﯿﺔ اﺳﺘﺨﺪام اﻟﻤﻮاد اﻟﻐﯿﺮ ﻣﻌﻤﺮة ) اﻟﺘﻲ ﻻ ﺗﺼﻤﺪ ( اﺳﺘﺨﺪام اﻟﻤﻮاد اﻟﻤﻨﺘﮭﯿﺔ اﻟﺼﻼﺣﯿﺔ اﺳﺘﺨﺪام ﻣﻮاد ﺟﺪﯾﺪة ﻟﯿﺴﺖ ﻣﻌﺮوﻓﺔ اﻟﻤﺼﺪر واﻟﺘﻔﺎﺻﯿﻞ وﻟﻢ ﺗﻔﺤﺺ ﻣﺪى ﺟﻮدﺗﮭﺎ ﻣﻦ ﻗﺒﻞ ﻓﻲ اﻟﺒﻨﺎء ﻓﻲ اﻟﺴﻮق اﻟﻤﺤﻠﯿﺔ اﺧﺘﯿﺎر ﻣﻮاد ﺑﻤﻮاﺻﻔﺎت ردﯾﺌﺔ اﻟﺠﻮدة أو دون اﻟﻤﺴﺘﻮى وﻏﯿﺮ ﻣﻄﺎﺑﻘﺔ ﻟﻠﻤﻮاﺻﻔﺎت ﺗﺠﺎھﻞ ﺗﺤﺪﯾﺪ زﻣﻦ وﻣﺪة ﺗﺸﻮﯾﻦ اﻟﻤﻮاد واﺧﺘﯿﺎر اﻻﻣﺎﻛﻦ اﻟﻤﻨﺎﺳﺒﺔ اﺧﺘﯿﺎر ﻣﻮاد ﺗﺸﻄﯿﺒﺎت رﺧﯿﺼﺔ اﻟﺜﻤﻦ ﺑﺤﺠﺔ ﻣﺤﺪودﯾﺔ اﻟﺘﻤﻮﯾﻞ
أواﻓﻖ ﺑﺸﺪة
م
ﻣﺠﻤﻮﻋﺎت اﻟﻌﯿﻮب واﻷﺧﻄﺎء
اﻟﺠﺰء اﻟﺮاﺑﻊ :ﺗﺄﺛﯿﺮ أﺧﻄﺎء وﻋﯿﻮب اﻟﺘﺼﻤﯿﻢ واﻟﺘﻨﻔﯿﺬ ﻋﻠﻰ ﺻﯿﺎﻧﺔ ﻣﺒﺎﻧﻲ ﻣﺪارس وﻛﺎﻟﺔ اﻟﻐﻮث ﻓﻲ ﻗﻄﺎع ﻏﺰة درﺟﺔ اﻟﺘﻄﺒﯿﻖ
ﻻ أواﻓﻖ ﺑﺸﺪة
اﺣﯿﺎﻧﺎ
171
أواﻓﻖ
ﺷﻜﺮا ﻋﻠﻰ ﺣﺴﻦ ﺗﻌﺎوﻧﻜﻢ
أواﻓﻖ ﺑﺸﺪة
3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8
اﻟﺰﯾﺎدة ﻓﻲ ﻣﯿﺰاﻧﯿﺔ اﻟﺼﯿﺎﻧﺔ اﻟﺰﯾﺎدة ﻓﻲ اﻟﻘﻮى اﻟﻌﺎﻣﻠﺔ ﻟﻠﺼﯿﺎﻧﺔ اﻟﺰﯾﺎدة ﻓﻲ أﻋﻤﺎل اﻟﺼﯿﺎﻧﺔ اﻟﺰﯾﺎدة ﻓﻲ ﻓﺘﺮة وﻣﺪة زﻣﻦ اﻟﺼﯿﺎﻧﺔ ﺗﻘﻠﯿﻞ ﺟﻮدة اﻟﺼﯿﺎﻧﺔ ﺻﻌﻮﺑﺔ ﻓﻲ اﻟﺘﺨﻄﯿﻂ ﻟﻠﺼﯿﺎﻧﺔ زﯾﺎدة ﺗﻜﺮار أﻋﻤﺎل اﻟﺼﯿﺎﻧﺔ ﺗﻘﻠﯿﻞ ﻋﻤﺮ اﻟﻤﺒﻨﻰ
ﻻ أواﻓﻖ
م
ﺗﺄﺛﯿﺮ اﻟﻌﯿﻮب ﻓﻲ اﻟﺼﯿﺎﻧﺔ
ANNEX 3: DESCRIPTIVE STATISTICS OF ALL FACTORS RELATED TO DEFECTS IN DESIGN STAGE
0.763
1
10
1.06
0.155
0.000
0.753
2
11
1.03
0.254
0.000
0.551
3
25
0.56
0.0011
0.000
0.500
4
31
0.65
0.540
0.000
0.494
5
32
0.62
0.887
0.000
0.484
6
33
0.58
0.232
0.000
0.465
7
34
0.68
0.539
0.000
0.459
8
35
1.06
0.757
0.000
0.456
9
36
0.85
0.736
0.000
0.446
10
38
0.76
0.716
0.000
0.379
11
40
0.83
0.463
0.000
172
P-value
SD
Person correlation
Rank with over all
Lack of attention to the design details and the concrete block walls and the intersection with the structural elements Improperly locating conduits and pipe openings at critical structural locations (sleeves) Ignore prepare soil tests in the projects and the depending on previous experience Ignore design of expansion / contraction / settlement joint and special construction joint Ignore the effects of the environment and the loads on structural elements and weather conditions on the materials used Inadequate concrete cover on structural elements Using of type of foundations inappropriate to soil characteristics Ignoring the dynamic loads effects on the stability of the building (elevators, air conditioners and generators) Ignoring the design for wind effects and design for earthquakes loads effects on the structure Ignore the difference in the adjacent soil layers and variation in soil conditions Exceeding the allowable deflection limits
RII
Factors
Rank with group
Table 1: Descriptive statistics of factors related to defects/errors in structural design
Selecting of exterior finishing and insulation material not relating to climatic condition Ignore the effect of local weather conditions at the building site for the design of the external shapes Unclearness of architectural detail design Architectural design not integrated with the other project drawings Designing inadequate expansions joint which don't lead to required purpose between finished faces ,ceiling and wall Designing narrow stairs ,passage and doors that obstruct the transfer of equipment and maintenance work process
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
Table 2: Descriptive statistics of factors related to defects/errors in architectural design
0.801
1
6
1.23
0.753
0.0003
0.788
2
7
1.24
0.723
0.0004
0.629
3
17
0.76
0.857
0.0005
0.529
4
27
1.33
0.447
0.0009
0.519
5
30
1.02
0.557
0.0007
0.453
6
37
0.90
0.135
0.0018
Table 3: Descriptive statistics of factors related to defects/errors due to owner
lack of workshops to discuss construction problems between the design, supervision and implementation Inadequate QA/QC programs during design stage Lack of technical updating and adequate training of staff and lack of awareness of construction technology Poor communication between the design team and the crew of maintenance / implementation
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
administration and his staff
0.873
1
1
1.64
0.410
0.0008
0.854
2
2
1.50
0.596
0.0007
0.779
3
9
1.10
0.719
0.0007
0.689
4
12
1.08
0.926
0.0006
173
Continue - Table 3: Descriptive statistics of factors related to defects/errors due to owner
0.629
5
16
1.02
0.781
0.0007
0.620
6
18
0.99
0.878
0.0006
0.617
7
19
1.04
0.741
0.0007
0.611
8
20
0.93
0.832
0.0007
0.585
9
22
0.82
0.844
0.0007
0.576
10
23
1.12
0.788
0.0006
0.554
11
24
1.00
0.656
0.0008
0.522
12
29
1.10
0.545
0.0008
P-value
SD
Person correlation
Rank with over all
Lack of documentation and archiving of the previous maintenance Lack of adequate budget for maintenance work Staff pressure to accomplish works times less than the required period The lack of clarity and integrity and to provide full information to the designer by the owner Lack of technical background and experience of the designer Misjudgment of environmental and climatic conditions Not be assigned to the engineer designing the parts that belonged to Ignore the designer to the properties, characteristics and behaviors of materials
RII
Factors
Rank with group
administration and his staff
Lack of auditing and archiving of approved as-built drawing documents electronically Dependence on repetition and lack of updating Poor and inaccurate details (detailed sections) Conflicts of architectural and civil drawings Lack of references (cross sections and detailed)
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
Table 4: Descriptive statistics of factors related to defects/errors due to drawing
0.832
1
3
1.43
0.844
0.0005
0.829
2
4
1.38
0.879
0.0004
0.674
3
13
0.73
0.963
0.0011
0.661
4
14
0.76
0.877
0.0012
0.529
5
28
1.08
0.273
0.0029
174
Not specifying quality assurance &control procedures (QA/QC) Lack of local specifications and standards related of requirements of materials and workmanship The specification is unclear and unrealistic Absence of laws to building maintenance items and specifications (manual or code) Not specifying to appropriate materials and specifications Not specifying to the allowable load limits Inadequate experience and expertise to design concrete admixtures
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
Table 5: Descriptive statistics of factors related to defects/errors due to specification
0.801
1
6
1.23
0.502
0.0001
0.788
2
8
1.17
0.475
0.0001
0.655
3
15
0.85
0.914
0.0001
0.589
4
21
1.00
0.826
0.0001
0.544
5
26
0.89
0.759
0.0001
0.418
6
39
1.11
0.424
0.0002
0.342
7
41
1.23
0.215
0.0003
ANNEX 4: DESCRIPTIVE STATISTICS OF ALL FACTORS RELATED TO DEFECTS IN CONSTRUCTION STAGE
Insufficient testing procedures during preliminary of water feeding and sewerage Lack of periodic inspection and monitoring Ignore of owner monitoring and checking importance Lack of experience and qualification of inspector Weakness of inspection rule in implementing corrective actions .
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
Table 6: Descriptive statistics of factors related to defects due to lack of inspection
0.848
1
4
1.45
0.902
0.0005
0.839
2
6
1.40
0.929
0.0005
0.728
3
9
1.04
0.930
0.0009
0.589
4
19
0.78
0.350
0.0033
0.551
5
26
1.06
0.359
0.0031
175
Table 7: Descriptive statistics of factors related to defects due to contractor administration
contract awarding on lowest bidders price Accelerate in execution to avoid delay and lack of quality Overlapping of finishing works quickly without giving every activity is suitable duration depending on engineering standards. Lake of workers experience and bad workmanship Lack of efficiency and expertise of contractor engineers Non-compliance with specifications The contractor engineer not resident fully in the site Lack of communication between the designer and owner.
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
and his staff
0.896
1
1
1.83
0.659
0.0005
0.848
2
3
1.49
0.765
0.0005
0.756
3
7
1.16
0.795
0.0006
0.639
4
13
1.31
0.594
0.0008
0.620
5
14
1.02
0.649
0.0009
0.617
6
15
0.940
0.670
0.0009
0.611
7
17
0.74
0.693
0.0010
0.573
8
23
0.97
0.492
0.0011
Table 8: Descriptive statistics of factors related to defects due architectural /structural
The damage due to the multi-use of formwork in the construction industry insufficient applying of painting layers improperly Inadequate insulation against water and sanitary works Inadequate curing the casted parts well Weakness and lack of homogeneity of concrete mix component or lack of compliance with the specifications components Remove framework of concrete early before the allowed time
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
construction
0.861
1
2
1.52
0.272
0.0002
0.839
2
5
1.43
0.283
0.0002
0.709
3
11
0.83
0.684
0.0001
0.592
4
18
1.05
0.880
0.0001
0.582
5
20
1.00
0.888
0.0001
0.573
6
22
1.03
0.861
0.0001
176
Continue -Table 8: Descriptive statistics of factors related to defects due architectural
SD
Lack of sufficient vibration Weakness contiguity and coherence between materials (syrups) Excavations with mechanical excavations tools near the existing building Inadequate concrete cover for reinforced concrete Lake of soil compaction Cold spacers between the new and old concrete Inaccuracy of dimensions and measurement
0.548
7
28
1.12
0.846
0.0001
0.529
8
29
0.76
0.818
0.0001
0.525
9
30
1.17
0.711
0.0001
0.522
10
31
0.83
0.151
0.0002
0.519
11
32
0.65
0.725
0.0001
0.516
12
34
0.74
0.751
0.0001
0.456
13
38
0.85
0.417
0.0002
P-value
Rank with over all
Person correlation
Factors
RII
Rank with group
/structural construction
0.715
1
10
0.98
0.416
0.0004
0.617
2
16
0.67
0.822
0.0002
0.519
3
33
0.62
0.863
0.0002
0.481
4
36
1.12
0.840
0.0001
0.434
5
39
1.01
0.704
0.0001
P-value
SD
Person correlation
Rank with over all
The negligence of the periodic maintenance of the equipment The lack of the required spare parts elements of the equipment Not taking into mind the availability of the equipment used in the maintenance in the local market during implementing Inadequate quality performance and quantity of the equipment Misuse of equipment
RII
Factors
Rank with group
Table 9: Descriptive statistics of factors related to defects due construction equipment
Choice of substandard materials that have a poor quality of specifications
0.750
1
177
8
0.99
0.499
P-value
Person correlation
SD
Rank with over all
Rank with group
Factors
RII
Table 10: Descriptive statistics of factors related to defects due construction materials
0.0010
Continue - Table 10: Descriptive statistics of factors related to defects due construction
2
12
1.14
0.529
0.0009
0.582
3
21
0.88
0.967
0.0006
0.563
4
24
1.19
0.922
0.0004
0.560
5
25
0.83
0.948
0.0006
0.551
6
27
0.90
0.915
0.0006
0.503
7
35
1.27
0.771
0.0005
0.478
8
37
1.00
0.602
0.0009
P-value
SD
Selection of material that is unsuitable for existing climatic conditions Selection of cheap finishing materials price due to lack of fund Ignore determine the time and duration of storage and handling of materials and choosing the appropriate places Ignore the basic physical and chemical properties of materials use of non-durable materials (which does not stand up) The use of new materials are not known and did not examine the details of their quality in construction before in the local market Use expired material
Person correlation
Rank with over all
0.703
RII
Factors
Rank with group
materials
ANNEX 5: DESCRIPTIVE STATISTICS OF FACTORS RELATED TO EFFECTS OF FAULTY ON MAINTENANCE
0.734 0.728 0.722 0.712 0.646 0.627 0.617 0.579
178
1.19 1.17 0.93 1.08 1.12 0.98 0.90 0.89
0.902 0.852 0.840 0.845 0.836 0.760 0.904 0.853
P-value
1 2 3 4 5 6 7 8
Person correlation
SD
Increase in maintenance works Increase in maintenance time\duration Increase in maintenance budget Increase in maintenance workforce Increased maintenance frequency Difficulty in maintenance planning Decreased building age Lower maintenance quality
Rank with group
Factors
RII
Table 11: Descriptive statistics of factors related to effects of faulty on maintenance
0.0012 0.0013 0.0016 0.0014 0.0014 0.0017 0.0015 0.0016
