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0000073525PROBLEMS OF BUILDING DEFECTS AFTER HANDING OVER THE KEY
NUR DARWANI BINTI ABD RAHMAN
A report submitted in partial fulfillment of the requirements for the award of degree of
Bachelor of Civil Engineering
FACULTY OF CIVIL ENGINEERING & EARTH RESOURCES UNIVERSITY MALAYSIA PAHANG
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ABSTRACT
Building defects can be considered as a normal issue arises in the construction industry in Malaysia. Small defects could lead to serious defects. These building defects can lead to accidents, injury, and time to complete a project longer and costs will be higher. The main purpose of this study was to identify the types of common defects in buildings and main causes for each of the types of defects in the building, to understand the concepts of Defects Liability Period, and to study and identify the rational method for rectifying the building defects. In relation to the objectives, the scope of this study will focus on housing that has been occupied for less than ten (10) years where the buildings are reinforced concrete. Questionnaire session conducted with contractors and owners which are housing residents and were focused around Pahang and Kelantan. Data were analyzed using Average Index Percentage through Microsoft Excel. The study found that seven (7) defect that usually occurs in the building which are wall cracking, plumbing defects, cracked tiles, erosion of mortar joint, roof defects, dampness and unstable foundations. Building defects are caused by shrinkage, water pressure, poor quality materials, movement building, fungal decay, rain water and landslides. The main concept of Defect Liability Period is purposed to rectify the defects in certain period which have been agreed by the contractor and owner. Contractor has their own responsibility and the owner has their own right when the defect occurs. Rational methods were identified to rectify the defects, such as through compressible filler, install the equipment properly, replace with new tile, using suitable mortar, remove and replace the damaged roof with new one, using water repellent treatment and underpinning. Types of defects in the building and the causes should be identified first so that the defects can be rectified with proper and effective methods. The responsible party should give more attention to this problem as serious defects can be avoided.
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ABSTRAK
Kecacatan bangunan merupakan perkara yang biasa diperkatakan dalam industri pembinaan di Malaysia. Kecacatan bangunan yang kecil boleh membawa kepada kecacatan yang lebih serius yang boleh mengakibatkan kemalangan, penambahan jangka masa projek serta peningkatan kos. Tujuan utama kajian ini adalah untuk mengenalpasti jenis kecacatan yang kerap berlaku dalam bangunan dan punca utama untuk setiap kecacatan tersebut, untuk memahami konsep Defect Liability Period serta mengkaji kaedah untuk membaiki kecacatan bangunan. Skop kajian ini tertumpu pada perumahan bangunan konkrit yang telah diduduki kurang daripada sepuluh (10) tahun. Sesi soal selidik dijalankan dengan pihak kontraktor dan penduduk perumahan dan tertumpu di sekitar Pahang dan Kelantan. Data kajian dianalisis menggunakan kaedah Percentage and Average Index melalui Microsoft Excel. Hasil kajian mendapati tujuh (7) kecacatan yang biasanya berlaku dalam bangunan iaitu keretakan dinding, masalah perpaipan, jubin retak, hakisan sendi mortar, kecacatan bumbung, kelembapan dan juga ketidakstabilan asas. Penyebab utamanya adalah pengecutan, tekanan air, bahan kurang berkualiti, pergerakan bangunan, pereputan kulat, air hujan serta tanah runtuh. Konsep utama Defect Liability Period untuk membaiki kecacatan dalam tempoh tertentu yang telah dipersetujui oleh kontraktor dan pemilik. Kontraktor mempunyai tanggungjawab mereka sendiri dan pemilik mempunyai hak mereka. Beberapa langkah dikenalpasti untuk membaiki kecacatan tersebut seperti melalui mampatan, memasang peralatan dengan betul, menggantikan jubin baru, menggunakan mortar yang sesuai, menanggalkan atap yang rosak dan menggantikan yang baru, menggunakan kaedah water repellent serta stripping. Jenis dan punca kecacatan perlu dikenalpasti terlebih dahulu supaya kecacatan boleh dibaiki melalui kaedah yang betul dan berkesan. Pihak yang bertanggungjawab perlu memberi lebih perhatian terhadap masalah sebegini supaya kecacatan yang lebih serius dapat dielakkan.
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TABLE OF CONTENT
CHAPTER TITLE PAGE
1 INTRODUCTION 1 1.1 Introduction 1 1.2 Problem Statement 2 1.3 Objectives 4 1.4 Scope of Study 4 1.5 Methodology 5 1.6 Significance of Study 6 2 LITERATURE REVIEW 7 2.1 Introduction 7 2.2 Definitions 8 2.3 Type of Defects 9
2.4 Common Defects Found in Building 11
2.4.1 Dampness 11
2.4.2 Wall Cracking 12
2.4.3 Erosion of Mortar Joints 13
2.4.4 Roof Defects 13
2.4.5 Cracked Tiles 14
2.4.6 Unstable Foundations 15
2.4.7 Plumbing Defects 16
2.5 Common Causes of Building Defects 17 2.5.1 Quality of Building Materials 17 2.5.2 Quality of Workmanship 17
2.5.3 Standard of Design 17
2.6 Factors of Building Defects 18
2.6.1 Dampness 18
2.6.1.1 Leak in Plumbing 18
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2.6.2 Wall Cracking 19
2.6.2.1 Settling 19
2.6.2.2 Shrinkage 19
2.6.3 Erosion of Mortar Joints 20
2.6.3.1 Weather 20 2.6.3.2 Building Movement 21 2.6.4 Roof Defects 21 2.6.4.1 Fungal Decay 21 2.6.4.2 Inadequate Timber 22 2.6.5 Cracked Tiles 22 2.6.5.1 Wall Size Changes 22
2.6.5.2 Poor Material 22
2.6.6 Unstable Foundation 23
2.6.6.1 Shrinking Clay Soil 23
2.6.6.2 Landslides 23
2.6.7 Plumbing Defects 24
2.6.7.1 Water Pressure 24 2.6.7.2 Improperly Installation 24
of Backwater Valve
2.7 Defect Liability Period 25
2.7.1 Liability for Defects 25
2.7.1.1 Construction Period 25 2.7.1.2 Defects Liability Period 26 2.7.1.3 Final Certificate 27 2.7.2 Defects Liability Period Flow 27
2.7.3 Contractor Obligations 29
after Completion
2.7.4 Standard Form of Contracts 30 2.8 Rational Defect Repair Method 32
2.8.1 Dampness . 33
2.8.1.1 Cement Slurry 33
2.8.1.2 Water Repellent 34
Treatment
2.8.2 Wall Cracking 35
2.8.2.1 Rebuild Part of the Wall 35 2.8.2.2 Compressible Filler 35 2.8.3 Erosion of Mortar Joints 36 2.8.3. l Refilling with Suitable 36
Mortar
2.8.3.2 Seal Surface 37
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2.8.4.1
Stripping38
2.8.5
Cracked Tiles39
2.8.5.1
Replaced New Tiles39
2.8.6
Unstable Foundation40
2.8.6.1
Underpinning40
2.8.7
Plumbing Defect41
2.8.7.1
Pressure Regulator41
2.8.7.2
Backwater Valve41
3 METHODOLOGY 423.1
Introduction42
3.2
Identify Problem and Issue42
3.3
Decide the Topic43
3.4
Define Objectives43
3
.
5
Gathering Data and Information44
3.5
.
1
Questionnaire Design44
3.6
Processing or Analyzing Data and Result45
3.7
Conclusion and Recommendation45
4 RESULT AND DATA ANALYSIS 46
4.1
Introduction46
4.2
Data Collection47
4.3
Data Analysis and Results Section A49
4.3.l
Respondent's Gender49
4.3.2
Respondent's Age50
4.3
.
3
Respondent's Profession51
4.3.4
Experience in Construction52
Industry4.3.5
Source of Information on53
Building Defect4.4
Data Analysis and Results Section B54
4.4.1
Types of Building Defects54
4.4.2
Factors of Building Defects56
4.4.2.1
Dampness59
4.4.2.2
Wall Cracking59
4.4
.
2.3
Erosion of Mortar Joints59
4.4.2.4
Roof Defects60
4.4.2.5
Cracked Tiles60
4.4.2.6
Unstable Foundations60
4.4.2.7
Plumbing Defects61
4
.
5
Data Analysis and Results Section C61
x 4.5.l Experiences in Defect 62
Liability Period
4.5.2 Source of Information on 63 Defect Liability Period
4.5.3 Opinion on Purpose of Defect 64 Liability Period
4.5.4 Opinion on Defect Liability Period 65 4.5.5 Parties Involved in Defect 66
Liability Period
4.5.6 Contractor Responsibility 67
4.5.7 Owner Rights 68
4.6 Data Analysis and Results Section D 69 4.6.1 Rational Defect Repair Methods 69
4.6.1.1 Dampness 72
4.6.1.2 Wall Cracking 72 4.6.1.3 Erosion of Mortar Joints 72
4.6.1.4 Roof Defects 73
4.6.1.5 Cracked Tiles 73 4.6.1.6 Unstable Foundations 74 4.6.1.7 Plumbing Defects 74
5 CONCLUSION AND RECOMMENDATION 75
5.1 Introduction 75
5.2 Conclusion 76
5.2.1 Objective 1: Study Types 76
& Factors of Building Defects
5.2.2 Objective 2: Understand the 78 Concept of Defect Liability Period
5.2.3 Objective 3: Analyze the Rational 79 Defect Repair Methods
5.3 Recommendation 80
REFERENCES 81
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LIST OF TABLES
TABLE NO. TITLE PAGE
4.1
List of Contractor and Housing48
4.2
Scale rating54
4
.
3
Analysis on types of building defects55
4.4
Scale rating56
4.5
Analysis on factors of building defects57
4.6
Scale rating69
4
.
7
Analysis on rational repair methods70
5.1
Types of defects and average index76
5.2
Ranking of types and factors of building77
defects5.3
Ranking of types and rational repair methods79
of building defectsXU
LIST OF FIGURES
TABLE NO. TITLE PAGE
1.1
Flowchart of Methodology5
2.1
Dampness defect12
2.2
Wall cracking defect12
2.3
Erosion of mortar joints defect13
2.4
Roof defects14
2.5
Roof truss defecs14
2.6
Cracked tile defects15
2.7
Unstable foundation15
2.8
Plumbing defects16
2.9
Cement slurry being applied to floor33
2.10
Durable water repellent34
2.11
Progress of rebuilt part of cracking wall35
2.12
Compressible filler36
2.13
Refill the joints with mortar37
2.14
Seal surface of mortar joints37
2.15
Stripping the roof38
2.16
Replacing a new tile39
2.17
Underpinning repair of existing structures40
4.1
Distribution of respondent's gender49
4.2
Distribution of respondent's age50
4.3
Distribution of profession that51
responded to the questionnaires
4.4
Distribution of respondent's52
experience in construction industry
4.5
Distribution of source of53
information on building defects
4.6
Analysis on types of building defects55
4.7 Analysis on factors of building defects 58xiii
4.8
Distribution of respondent's62
experience in Defect Liability Period
4
.
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Defect Liability Period of information sources63
4.10
Distribution of opinion on64
Defect Liability Period purpose
4.11
Respondent's opinion on period of65
Defect Liability Period
4.12
Distribution of opinion on parties involved66
4.13
Distribution of respondent's67
opinion in contractor responsibility
4.14
Distribution of respondent's68
opinion on owner rights
4.15 Analysis on rational repair methods of building 71 defects
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LIST OF APPENDICES
APPENDIX TITLE PAGE
A New Strait Times, 6 April 2010 83
B New Strait Times, 1 May 2007 87
c
New Strait Times, 2 November 2007 88 D New Strait Times, 5 November 2004 91E New Strait Times, 17 June 2007 92
CHAPTER I
INTRODUCTION
1.1 Introduction
An imperfection or flaws are the meaning of defect. Building defects can be
a vexing problem for new home owners. A new home that full with defects is a bad
package for new home owners which could be say that they buying a house that was already occupied. These defects will arise many implications as it shows negligence and lack of concern towards the important part in construction.
Housing building is a complex process, generally involves a broad field of materials and number of subcontractors to complete such as roofers, plumbers,
electricians and the others. In housing, mistakes can and do occur in defect results.
Minor defects can lead to serious defects that bring to some very critical
complications. Cost of repair project will be higher if the defects detected after the
building finished and also the longer building defects are left in place the more dangerous the building becomes too if the defects in serious case. It is never a good idea to hire a contractor of dubious skill just only to save the budget.
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Usually the condition of construction is constantly changing. Companies
must develop and improve continuously to become succeed. Changes must be based on knowledge of both the environment and one's own work. In this situation
knowledge of defects nature that has occurred is necessary and very important.
Effective actions can be taken to improve the process with this knowledge
(P.-E.Josephson & Y.Hammarlund, 1998).
1.2 Problem Statement
As Malaysian Institute of Engineers President, Datuk Keizrul Abdullah said
in New Straits Times 6th April 2010 that "It's only when a building collapses that
everybody wakes up. Then we forget about it until the next problem arises. In some
cases, it is necessary to have rules, regulations and laws"(Appendix A). Mostly
small defects occurred will be assumed as nothing happen in the building. But there will be a huge confusion when serious damages detected.
Small defect classified as zero problem. But when big defect occured, there will be disputation as the defects will give bad effect and affect the human safety. This approved by this statement, "Serious infrastructure defects such as cracking walls and beams may lead to possible building collapse and jeopardise the safety of
our children." This statement was issued by Cheah Chee Ho in New Straits Times
5th Nov 2004 (Appendix D).
In New Straits Times 151 May 2007, Datuk Seri Abdullah Ahmad Badawi said
that "Maintainence is very important. I have said this many times but these people,
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building need to be checked details to detect any defects even the small one so that if any defects occured it can be avoided early and also easy to solve.
As stated in New Straits Times 2nd Nov 2007 by European Construction community, "Had defects occurred during construction, the contractor may have to
spend a whopping 16 per cent (16%) in construction costs to rectify the defects,
which can easily wipe out all his profits. Poor quality and defects lend the
impression that the construction sector does not seem to care about its customers"
(Appendix C). This shows that defects only give more problem once it occured such
need to spend money to rectify these poor quality and give bad impression to the customers and the future customers.
Elizabeth John wrote in the New Straits Times 17 Jun 2007 that "One
building defect after another and we are suddenly asking where all the good
workmen have gone" (Appendix E). Nowadays, there are many defects issues
appeared and make people wondering why is it happen and start asking about the quality and dispute the skilled workers.
These can be concluded that the defect problem will not considered as a
serious issue as long as the building not collapse terribly and not affect the human safety. Nowadays, people consider the building quality is the second thing which
categorised as unimportant issue. For them, the most important are time and cost as
both give more profit and advantages to them. This quality should be taking serious as they have potential and can contribute to building defects if it considered as adjuncts.
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1.3 Objectives
From the problem statement above, this study is prepared with three (3)
objectives as follow:
L To study the types and factors of building defects.
IL To understand the concept of Defect Liability Period. ui. To analyze the rational defect repair methods.
1.4 Scope of Study
In relation with the objectives of the study, the scopes of this research will cover few areas which are will be limited and focused at Pahang and Kelantan and
also will be conducted after the buildings have been occupied less than ten (10) years
which the buildings with reinforced concrete features will be focused. The questionnaire will be prepared and interview will be conducted with persons involved in contractor and building owner.
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1.5 Methodology
Start
Identify Problem and Issue
Decide the Topic
Define Objectives
Gathering Data and Information
Questionnaire Literature Review
Book Newspapers
Article Journal Internet Research
Processing & Analyzing Data and Result
Microsoft Excel
Conclusion and Recommendations
End
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1.6 Significance of Study
It is necessary to have knowledge about defects, its causes and risks before perform rational defect prevention. The purpose of the study is to stimulate improvements by indicating where preventive measures are most effective as well as how to perform them.
This study will give contribution to the parties involved in the construction industry. This study also can be used as a reference for further studies and further improvement for related research in the future. By identifying the type of housing with high demand, this would make a good investment.
Early steps to prevent defects can be taken when identifying the damage that is common. This can be as the guidance to provide good quality in construction. Result of the damage list developed by the buyer to the developer hopes to reduce the defects on the minimum level for future projects.
CHAPTER2
LITERATURE REVIEW
2.1 Introduction
The nature of the building and construction process often leads to minor defects. Building defects will become an issue only if they are major or excessive. There is, however, an increasing concern over building defects which arise after new residential property developments are taken over by home buyers. For instance, Razzi (1995) reports the case of a home buyer in Salt lake City, Utah, USA, who encountered numerous building defects and prolonged delays in rec;tifying the
defects. The Straits Times report quoted above is one of several articles which focus
on the prevalence of building defects in Singapore.
Building defects will lead many implications that represent the negligence and also show lack of concern. In terms of building construction, there are few Parties involved in making decision which are designer or consultant, contractor and owner. One of them or all of them may be the cause of building defects. Directing of project management uncertain which lack of information, changing of result that
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not consistent, inefficient site survey also can cause the defects occur on building
(Dr. Ahmad b. Ramly, 2001).
2.2 Definition
A building defect is that makes a project unsafe, dangerous or causes real damage to the consumer. Building defects affect society at large due to possible danger posed which result direct and indirect cost in repairs the damage, abnormally high maintenance, disputes and possible loss of building use.
Usually building defects include any deficiency in the performing or
furnishing of the planning, design, inspection, supervision, construction or
observation of construction new building, where there is a failure to construct the building in a reasonably workmanlike manner and or the structure fails to perform in the manner that is reasonably intended by the buyer.
Defective building construction not only contributes to the final cost of the product but also to the cost of maintenance, which can be substantial. Defective
construction may lead to the complete failure of the structure. However, no structure
is perfect hundred percent. Even the best built and the best maintained structures
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2.3 Types of Defect
In general terms defects are where the standard and quality of workmanship and materials is deficient. Defects can be classified into two (2) main categories which are latent defects and patent defects (Anon, 2007).
Latent defects are defects which are not discoverable by normal examination or testing that manifests it after a period of time but the patent defects is otherwise that are defects which can be discovered by normal examination or testing (Anon, 2007).
Professor Vincent Powell-Smith describes a 'patent' defects as (Harbans Singh, 2003):
"A defect which is discoverable by reasonable inspection. In the context of engineering contracts, the term embraces all the items which the engineer or engineer's representative must be expected to find and bring to the contractor's attention so the remedial works can be carried out. Patent defects are plain to see, or at least, that is the theory. Whether the engineer could or should have seen defects on site during site visits has exercised more than one judicial mind ... "
However, in 'Construction Law in Singapore and Malaysia', the authors ascribe a rather simple definition to the term 'patern' defects (Nigel M Robinson,
1996):
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Both references ascribe the 'latent' defects as the following definitions (Harbans Singh, 2003):
"A defect which is not discoverable during the course of ordinary and reasonable examination but which manifests itself after a period of time. In building and civil engineering work the most common application is defects becoming apparent after
the maintenance period expired. "
Other than that, Robinson and Lavers explain a 'latent' defects m the following words (Nigel M Robinson, 1996):
" ... a defect that cannot be discovered by normal examination and testing ... "
In other words, patent defects are defects that can be either seen or can be discovered by means of reasonable inspection, examination or testing. The establishment of such defects is not merely confined to the defects that can be plainly seen or observed but encompasses also those that become apparent on reasonable inspection, examination and if necessary upon testing. The latter requirement to testing imposes a more onerous responsibility in terms of discoverability (Harbans Singh, 2003).
In contrast, latent defects are the ones that are either inherent or those that do not manifest themselves upon reasonable examination, inspection or testing. These comprise defects which will become apparent or noticable or capable of being discovered only when they become patent (Harbans Singh, 2003).
In the definitions for both categories of defects, the emphasis is on the words
'normal' or 'reasonable' whether these can be in relation to any inspection or examination or testing in establishing the type of defect in question. The
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requirement therefore does not call for a meticulous or exhaustive process in establishing the said defects. The difference between these two (2) types of defects also extends to their consequential effects especially in terms of duration of liability, with latent defects involving a longer duration both contractual and under various statutory provisions (Harbans Singh, 2003).
2.4 Common Defects Found in Building
2.4.1 Dampness
Structural dampness refers to the presence of unwanted moisture in the building structure, either the result of intrusion from outside or condensation from within the structure. Oxley (1983) defines dampness as an atmosphere wetter than eighty-five percent (85%) relative humidity; and a material is damp if it is in equilibrium with this humidity. All dampness is water out of place, however it is convenient to classify its different manifestations by their source and the routes by which unwanted water enters the inhabited areas.
Dampness tends to give secondary damage to a building. The unwanted moisture enables the various fungi growth in wood, causing rot. Then, plaster and paint deteriorate and wallpaper loosens. Figure 2.1 below show the defect of dampness in the building:
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Figure 2.1: Dampness defect
(Source: Problem Survey, 2008, P-CON Building Surveyors Sdn. Bhd.)
2.4.2 Wall Cracking
External walls may be harmful to a building if they are structurally unsound as it apart from distributing loads from roofs and floors to foundations. Vertical or diagonal cracks in the wall are common symptoms of structural instability. Such defects should be investigated promptly and the causes diagnosed (Prof. Dr. A. Ghafar Ahmad, 2004). Figure 2.2 below give a view of line crack on the wall:
Figure 2.2: Wall cracking defect
(Source: PreConstruction Condition Survey, 2008, P-CON Building Surveyors Sdn. Bhd.)
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2.4.3 Erosion of Mortar Joints
The main function is to even out irregularities of individual blocks, whether
they are bricks or stones. It provides some adhesion between the blocks at the same
time. Wall of mortared are less subject to erosion because of their footing, but their mortar joints and the surface of the stones themselves can crack and take in water, then freeze and split. The damaged wall that does not receive timely attention poses
a safety hazard. Decayed mortar can be removed forcibly by the use of a mechanical
disc or carefully raked out by using a knife or spike manually. Figure 2.3 below
shows some view of erosion of mortar joints:
Figure 2.3: Erosion of mortar joints defect
(Source: Fretting Mortar and How to Fix It, Residential Settlement)
2.4.4 Roof Defects
Roof is very important to treat aging roof tiles as it often acts as a weather
shield besides being one of the main structures in a building. In Malaysia, clay roof tiles have been widely used in the heritage buildings. They appear in different sizes and colors usually reddish, depending on the manufacturer that produced them. (Prof. Dr. A. Ghafar Ahmad, 2004). Figure 2.4 shows some broken roof and the Figure 2.5 shows poorly joint roof truss in every unit:
