i

Study on Heritage Building via Lime Plaster in

Malaysia: Case Study in

George Town, Penang

By

AMIRAHTUL `AQILAH BINTI MOHAMED SABRI

BACHELOR OF SCIENCE

in

HOUSING, BUILDING AND PLANNING (BUILDING SURVEYING)

UNIVERSITI SAINS MALAYSIA

JUN 2014

Supervisor:

Dr. Mohd Zailan B Sulieman

ii

DECLARATION

I declare that this project report entitled Study on Heritage Building via Lime Plaster

in Malaysia, Case Study of Georgetown, Penang is the result of my own research except

as cited in the references. The project report has not been accepted for any degree and is

not concurrently submitted in candidature of any other degree.

..........................................................................

Amirahtul `Aqilah Binti Mohamed Sabri

IC No.: 891007-01-6470

Matric No.: 110603

JUN 2014

Verification by:

Dr. Mohd Zailan B Sulieman

Supervisor of Final Year Research Project

Jun 2014

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ABSTRAK

Kesedaran pengunaan bahan serasi dalam pemuliharaan bangunan bersejarah

telah menyebabkan kelahiran semula teknologi aplikasi pengunaan kapur. Selain itu,

pengetahuan mengenai prosedur penyediaan bahan akan mempengaruhi kualiti akhir

kapur. Namun, percanggahan pendapat terhadap penggunaan kaedah pemuliharaan

yang betul masih wujud di kalangan konservator.Tujuan kajian ini dijalankan adalah

untuk mengkaji kerosakan dan mencadangkan kaedah pemuliharaan yang boleh di

aplikasikan pada dinding luar bangunan warisan di George Town, Pulau Pinang. Fokus

kajian ini ialah bahan kapur, memandangkan ia telah digunakan pada sebahagian besar

dinding luar. Kajian ini dijalankan berdasarkan kaedah kualitatif, seperti kajian literatur,

pemerhatian visual dan temuduga. Daripada kajian rintis terhadap 85 bangunan

bersejarah di zon teras, ia telah mendapati bahawa terdapat tiga punca kecacatan

dinding luar iaitu perubahan iklim , pencemaran udara , dan isu penyelenggaraan.

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ABSTRACT

Awareness of the used of compatible material in historical building conservation has

resulted in the rebirth of lime technology and application. Then again, the knowledge of

the preparation and procedure influencing the final quality of lime is still limited and

disagreement regarding the conservation treatment still continues to exist among the

conservator. The purposed of this paper is to highlight the deterioration and suggests

possible treatment of external wall of heritage building in George Town, Penang. Since,

lime have been used on most part of the external wall, therefore it will be the focus of

this study. The study was conducted based on qualitative method, such as literature

review, visual observation and interview. From the pilot survey of 85 historical

building in core zone, it have been found that from the uses of lime based material the

possible defect is causes by three factor climatic charge, air pollution, maintenances

issues. This study will be focusing on lime material. Therefore, the possible restoration

for external wall was established in that area.

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ACKNOWLEDGEMENTS

In the name of Allah Most Benevolent and Most Merciful. Alhamdulillah, I am grateful

and cherish to God, for making me successfully complete this dissertation with His

allowance. First and foremost, I would like to express my greatest gratitude sincerely to

my father and mother for their never ending encouragement and to my supervisor, Dr.

Mohd Zailan B Sulieman who has given me the guidance, advice, invaluable suggestion

and unfailing support to me. Also, I would like to express my sincere appreciation to the

Coordinator of Building Surveying final year project course coordinator, Sr Dr. Md

Azree Bin Othuman Mydin for his guidance. I owe a special thanks to those who agrees

to be interviewed and give me the benefit of their knowledge in order to obtain

information. My honest appreciation also goes to my colleagues

(Masya,Farisya,Syida,Aizad), for their support and encouragement during the

preparation of this final project. Throughout my everlasting appreciation, I would like to

extend my heartiest thanks to all lecturers of School of Housing, Building and Planning,

Universiti Sains Malaysia for their kindness and motivation. Last but not least, my

sincere and heartiest appreciation to my sister, Aminahtun Adilah, for her help and

never ending encouragement. Thank you.

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TABLE OF CONTENTS

DECLARATION ............................................................................................................. ii

ABSTRAK ...................................................................................................................... iii

ABSTRACT .................................................................................................................... iv

ACKNOWLEDGEMENTS ..................................................................................................... v

TABLE OF CONTENTS ...................................................................................................... vi

TABLE LIST .................................................................................................................. ix

FIGURE LIST ................................................................................................................. x

CHAPTER 1 .................................................................................................................... 1

INTRODUCTION ........................................................................................................... 1

1.0 Introduction ........................................................................................................ 1

1.2 Background Study .............................................................................................. 3

1.3 Problem Statement ............................................................................................. 6

1.4 Objective of Study ............................................................................................ 11

1.5 Scope of Study .................................................................................................. 11

1.6 Limitation ........................................................................................................ 12

1.7 Summary of Chapters ....................................................................................... 12

1.8 Term and Definition ......................................................................................... 13

CHAPTER 2 .................................................................................................................. 15

LITERATURE REVIEW ............................................................................................. 15

2.0 Introduction ...................................................................................................... 15

2.1 Traditional Material. ......................................................................................... 17

2.1.1 Timber ....................................................................................................... 18

2.1.2 Stone .......................................................................................................... 18

2.1.3 Clay ........................................................................................................... 18

2.1.4 Lime .......................................................................................................... 19

2.3 Traditional Binder ............................................................................................ 20

2.3.1 Mortar ........................................................................................................ 22

2.4 Lime Mortar Ingredient .................................................................................... 23

2.4.1 Hydraulic Lime ........................................................................................ 25

2.5 Production of Lime ............................................................................................... 31

2.5.1 Lime Slaking ............................................................................................. 33

2.5.2 Lime Mixing ............................................................................................. 35

2.5.3 Lime Storage ............................................................................................. 38

2.6 Lime Plaster ..................................................................................................... 39

2.7 Lime Wash ....................................................................................................... 40

2.8 Lime Characteristic. ......................................................................................... 40

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2.9 Mortar Damage ................................................................................................. 41

2.9.1 Moisture .................................................................................................... 42

2.9.2 Air Pollution .............................................................................................. 43

2.9.3 Soluble Salt ............................................................................................... 43

2.9.4 Biological Colonization. ................................................................................ 45

2.9.5 Structural Problems ................................................................................... 45

2.9.6 Poor Workmanship ................................................................................... 45

2.9.7 Improper Curing ........................................................................................ 46

2.10 Restoration of cultural heritage..................................................................... 47

2.10.1 Conservation ............................................................................................. 47

2.10.2 Conservation Concept ............................................................................... 49

2.10.3 Restoration ................................................................................................ 50

2.11 Previous Research Method .......................................................................... 52

2.12 Conclusion .......................................................................................................... 53

CHAPTER 3 .................................................................................................................. 54

METHODOLOGY ........................................................................................................ 54

3.0 Introduction ...................................................................................................... 54

3.1 Research Methodology ..................................................................................... 55

3.2 Literature Review ............................................................................................. 56

3.3 Data Collection ................................................................................................. 57

3.3.1 Primary data ................................................................................................... 57

3.4 Data Sample and Data Collection .................................................................... 60

3.5 Data analysis ..................................................................................................... 61

CHAPTER 4 .................................................................................................................. 62

DATA COLLECTION AND ANALYSIS .................................................................. 62

4.0 Introduction ...................................................................................................... 62

4.2 Data Finding ..................................................................................................... 62

4.2.1 Background ............................................................................................... 62

4.2.2 Current Stated of Historical Building in George Town, Penang ................... 64

4.3 Data Analysis ................................................................................................... 67

4.3.1 Surface Condition (Discoloration, Chalking, Staining, Peeling Paint, Paint

Bulging) .................................................................................................................. 67

4.3.2 Mortar and Plaster ..................................................................................... 70

4.4 Effect of Using Incompatible Material ............................................................. 72

4.5 Treatment for exterior surface. ......................................................................... 74

4.5.1 Lime Mortar and Plaster............................................................................ 74

4.5.2 Painting ..................................................................................................... 77

4.6 Conclusions ...................................................................................................... 79

viii

CHAPTER 5 .................................................................................................................. 80

CONCLUSION AND RECOMMENDATION FOR FURTHER RESEARCH ..... 80

5.0 Main Conclusion .............................................................................................. 80

5.1 Factor Effecting historical building in George Town, Penang. ....................... 81

5.2 Repair Method Process ..................................................................................... 82

5. 3 Recommendation for Further Research ........................................................... 86

REFERENCES .............................................................................................................. 87

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TABLE LIST

Tables Page

TABLE 2.0 Cementation Index 24

TABLE 4.0 Factor That Causes Damage On Original Mortar And

Plaster And Damage Type

68

TABLE 4.1 Sd Value To Determine Breathable Paint 75

x

FIGURE LIST

Figures Page

FIGURE 1.0 Pre-War Building By Architecture Style And Year Built 2

FIGURE 1.1 Percentage Of Historic Building That Need To Be

Conserve In Malaysia

7

FIGURE 1.2 Common Defect Location In Historic Building In Malaysia 7

FIGURE 1.3 Poorly maintain historic building 8

FIGURE 1.4 Common Defect In Historic Building 9

FIGURE 2.0 Early Stage Damage Show Salts Crystals 17

FIGURE 2.1 Moisture Evaporation 18

FIGURE 2.2 The Burning Lime Cycle-Burning And Hardening Of Non-

Hydraulic Lime

30

FIGURE 2.2 Hardening Process Of Lime Mortar 36

FIGURE 2.3 Distribution Of Adventives Within The Material 50

FIGURE 3.0 Research Methodology 53

FIGURE 3.1 Principle Of Diagnosis 55

FIGURE 4.0 World Heritage Site, Penang 61

FIGURE 4.1 Historic Building Condition In George Town, Penang 62

FIGURE 4.2 Number Of Building With External Wall Defect In George

Town, Penang

63

FIGURE 4.3 Two Type Of Stain Found In George Town, Penang 64

FIGURE 4.4 Erosion Of Mortar 65

FIGURE 4.5 Discoloration On Wall 65

FIGURE 4.6 Peeling Paint On Exterior Wall 66

FIGURE 4.7 Blistering Paint 67

FIGURE 4.8 The Used Of Cement To Heritage Building 69

FIGURE 4.9 Wall Render Deterioration Due To The Use Of Cement

Render

70

FIGURE 4.10 Mock Up Sample 72

FIGURE 4.11 Lime Slaking 74

FIGURE 4.12 Sample For Pigment Colours 76

FIGURE 5.0 Black Layer On Surface Of Historical Building 78

FIGURE 5.1 Flow Diagram of Suggested Experiment Method Used in

Process Designing of Repair Plaster

81

1

CHAPTER 1

INTRODUCTION

1.0 Introduction

Conservation of heritage building in Malaysia started in 1970s where the first

building to be preserved is the Central Market building In Kuala Lumpur (Harun, 2011).

In 1988 Malaysia have become member of UNESCO`s Convention Concerning the

Protection of the World Cultural and Natural Heritage. Since then more and more

building have been conserved and restored with the references and guidance of

international charters. National Museum, 1992, heritage building inventory study

estimated approximately 35,000 buildings before war should be conserved in 265 cities

survey, (Zuraidi, 2011). Undoubtedly these building are important in determine the

historical past of the national but given the age of the building at present, this structure

will not be standing for too long unless proper maintenances work and identification of

historical building may contributed to decaying of building thus resulting to decrement

in the number of historical building

Heritage culture and building in Penang have become among value asset in

Malaysia. George Town inner cities most treasure architecture are located and can

divided into several zone, it culture has been molded by the succession of civilization

that arrive and shaped its urban growth. Heritage building in the inner city exposes the

sense of comprimise between the pioneers, earlier settlers and later immigrants

(Mohamed, 2005). Similarity ,Lim, 2008, stated that, the significant heritage character

2

of George Town, Penang is reflect upon the predominant pre war buildings, the heritage

buildings dates back to between late eighteen century and early nineteenth century.

Figure 1.0: Pre war Building by architectural styles and year built (Lim, 2008)

3

1.2 Background Study

Georgetown, Penang has more than 12,000 old buildings and most of these

historic building were constructed with brick, stone and lime mortar (Muhamed, 2002)

In 1996 the Penang State Conservation Committee, consisting of government agencies,

local authority and private sectors, was formed to monitor and control any development

in the conservation areas. Many heritage buildings in Georgetown have been protected

under Antiquities Act of 1976, Guide for conservation area and heritage

building(MPPP),2005, and National heritage act 2005

Article 1 of the Burra Charter stated that the fabric of some historical buildings

may contain the cultural importance of which the buildings itself should be viewed as

valuable artifacts. The main purpose of the conservation is to maximize the

conservation of the cultural importance by performing continual improvement. It also

stated that if buildings are evidently found to possess the cultural importance,

maintenance works therefore should be performed to retain the buildings. There for

maintenance is part of the conservation process. Highlighted in their research that there

is a bond between conservation and maintenance works as the latter is an approach to

prolong the lifespan of the building and at the same time if works undertaken are poorly

performed, it may contribute to the loss of the original building fabric.

There for materials is an important element in conservation project. Heritage

building conservation project should match original material. There are four main

traditional material used to build a heritage building such as timber, stone, clay and

lime.

4

One of traditional material in heritage building is Timber. Buildings constructed

with timber are indeed affected by its agent and serious defect and can reduce the

building value. Conservation of timber is by machining the timber species and size. In

addition the repair might be fully or partial replacement and preservation of timber and

control insect invasion to prolong and extend its function in building. Timber in heritage

is use for roof structure, floor structure, floor board, partition, frame, door, decorative

screen and carving, staircase, balustrade and handrail.

Next, green traditional material is stone. Stone is use for corbel bracket for the

main building for upper floor, granite slab across the open drain, step up from the drain,

edge of five foot way, rubble wall, bottom of the staircase, foundation stone and in

some case as ground floor. During the stone repair work, the stone need to match the

original material, function and design where it possible.

Also clay has been considered as green heritage material for heritage building.

Clay are uses in terracotta clay roof tile, brick for walls, brick dust in lime

mortar/plaster, lime concrete, brick piece for below ground hardcode, terracotta tile,

clay invert for drain. George Town was built on a swamp, by using the breathable clay

brick walls it allows ground moisture inside to cool the room.

Lime has been use as building and decoration material from decade in Malaysia.

First record of Manual for Conservation Lime are in 1998 by David Yeo. Lime is a

product of calcium carbonated which commonly takes the form of limestone, as found

and quarried in lime stone hill and also can be found in coral, sea shells, and chalk.

5

When any form of calcium carbonate are burnt at between 850 and 1300 degree,

conversation to calcium oxide take places and better know as quiklime.

Lime is a green material and it also can be used in new building. For heritage

building lime is used in:-

1. Wall

The use of lime in wall is as lime mortar between the brick, lime plaster to cover

the brick and lime wash for wall painting.

2. Roof

Lime in roof used lime plaster for the wall, flashing and under the roof tile.

3. Floor

Lime in floor is used as lime concrete mix

Selection of the best methods and materials can decreased the defect to occur

second time in the future. Beside the material function during construction, the material

also carries an aesthetic value depending on their architectural form and construction

techniques. Restoration of historic building built with lime mortar creates challenges for

architect, conservator, and worker tasked with masonry restoration. The original

material and method involving lime have been suspended by the use of cement with its

own material and technique. However, cement have failed to provide a successful role

as binder for the restoration of historic building built with lime.

6

1.3 Problem Statement

Georgetown faces saveral problem in dealing with the issues of historic

building. Kamal,2008 stated that the lack of technical knowledged in repairing and

maintaining historic building is a major problem becauses repair and maintenances

stage required an understanding of and analysis of building diagnoses. Understanding

the building defect is simply a logical way of proceeding from the evident to the causes

of defect after which remedies can be prescribeb

Today, these historic building are in different physical stage, some are in

relatively good condition,while many are in an inadequate stated. However, due to the

existences of this historical building, George Town has become tourist attraction

(Mohamed, 2001). Due to that George Town, Penang have benefited cultural and

economically. Considering the benefits, it can be conclude that it is esstential to ensure

that the historic building continue to exist. Pilot study done by (Kamal K. W., 2008)

stated that out of 209 historical building survey in malaysia, 14% of building defect

occur at external wall, 87% of historical building need to be conserved, and 74% show

that the building was not conserved properly.Figure 1.1 and figure 1.2 show data

finding by Kamal,2008

The general objective of this study is to identified the mean of restoring historic

building in George Town, Penang. Lime based material are the most commanly used in

historic building restoration therefore this study will focused on Lime based material.

7

Figure 1.1: Percentage of historic building that need to be conserve in Malaysia (Kamal,

2008)

Figure 1.2: Common Defect Location in historic building in Malaysia (Kamal, 2008)

8

Loking at the current stated of most historic building in George Town, Penang

it`s quite clear that most of the building have not been properly maintain and some of

the building are repair attemp have not been very effective.

Figure 1.3 : Poorly maintain historic building.

A review of several literature reveal the important of understanding the original

material used and the factor and process responsible for their deterioration before

attempt any restoration work. ICOMOS, 2003 stated that the development of the

restoration material and method should based on an understanding of the performances

requirements of the material, taking account, nature and current condition of the existing

materials, functions of new material and the degree of exposure.

9

Material defect are due to misuse and abuse of material in the conservation of

the building. However, material defect became visble only after a period of time or

through usage. By through study of the defect, actual cause can be determine and may

be avoid. Technical knowledge and proficiency and indulgent of building construction

are necessary to accurately recognize the root of building defect and the remedial

measure essential to put the defect right. Unsuitable use of material during repair work

will contribute to building defect.

Study by Ahmad, 1994, show the common defect found in heritage building.

Based on his finding during his study the highest defect percentage are errosion of

mortar joint 38.4 percentage, follow by peeling paint with 30.7 percentage, than

defective plastering rendering with 21.10 percentage and last 9.8 percentage are other

defect.

Figure 1.4: Common Defect in Historic building (Ahmad, 1994)

10

Zawawi, 2013, state that hundreds of historic masonry buildings are threatens

by new development due to the lack of maintenance as well as the use of inappropriate

repair method and incompatible repair material. The lack of proper maintenances work

and identification of historical building have contribute to decaying of building thus

resulting to decrement in the number of historical building.

Conservation of historic building is a process which will lead to the prolongation

of the life of cultural property for its utilazation now and in the future. But before

practicing conservation, one must have broad understanding of the field itself. This is to

ensure that any action carried out during the conservation work is properly performed

and is in accord, not only with the building requirement but within the scope of

conservation.

Due to lack of time the study will focus on the uses of lime material on heritage

building on external wall. Lime are widely use in heritage building such as painting

(lime wash),surface(lime plaster),between bricks of structure(lime mortar), ground and

terraces (lime concrete). Thus the study establish the proper treatment for lime base

material.

11

1.4 Objective of Study

The main purposed of this study is to identify the remedial technique that would

compatible with building lime. Hence, it is importance to understand the original

material used and the factor and process responsible for deterioration. The selection of

the suitable repair method and material during the building conservation can decreased

the defect to occur second time in future. There for the Objective of this research has

been identified as follow:-

1) To identified current historical building condition.

2) To determine the common type of external wall defect

3) To determine the restoration guide for building conservation process.

1.5 Scope of Study

This study focus to the lime material since it is one of the four main material

uses for repair work and the maintenances framework used for heritage building. This

study will be focus in Penang, heritage core zone. The researcher will come up with

structure interview to collect data beside literature review. Data collected will determine

the relationship between the technical knowledge of material property and remedial

method. Thru the data collection, researcher will also be able to conclude the overall

finding. Party that will be involves:-

1) Georgetown World Heritage Incorporate.

2) Heritage Department of Municipal Council of Penang Island (MPPP)

3) Conservator contractor

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1.6 Limitation

Several limitations are found when conducting the study. Among them are:-

1. Due to time constraint the study are limited to building in the core area of

George Town, Penang, and World Heritage Site.

2. The focus of this study is Lime material since lime mostly used as restoration

material in conservation.

3. The study does not involve laboratory testing. Study only cover result from

previous laboratory test by other researcher.

4. Study are done in Penang State, thus the study shall not represent other state in

Malaysia

1.7 Summary of Chapters

Chapter 1 discuses detail about the background of study and problem statement

for this research. In order to give overall guideline, the aim and objective are defined in

this chapter including the scope of study and research methodology.

Chapter 2 describes the definition and background of material use in

conservation project. These chapters briefly explain the building conservation, lime

production and previous research by research.

Chapter 3 explains about the research methodology for this study. This chapter

also discussed in detail regarding methodology use for this study to complete the

research.

Chapter 4 provides the result obtain from data collection. The finding are

analyzed and discussed in this chapter. Data collection was done through the interview,

13

observation and data from previous conservation report prior to lime material. Chapter 5

presents the recommendation and conclusion to the study.

1.8 Term and Definition

Term and definition as explained by European Standard, BS EN 459-1:2010:-

1. Lime.

Calcium oxide or hydroxide, and calcium-magnesium oxide produce by thermal

decomposition (calcination) of naturally occurring calcium carbonate (limestone,

chalk, shell) or naturally occurring calcium magnesium carbonated.

2. Building Lime.

Group of lime product, exclusively consisting of two families: air lime and lime

with hydraulic properties, used in application or material for construction and

building.

3. Lime with Hydraulic Properties.

Lime that has the property of setting and hardening when mixed with water or

under water. Reaction with atmospheric carbon dioxide is part of hardening

process. Lime with hydraulic properties is divided into three sub categories,

natural hydraulic lime (NHL), formulated lime (FL) and hydraulic lime (HL).

4. Quicklime

Quicklime is the reaction of calcium oxide when limestone burn continuously

with high temperature.

5. Slaking

Slaking is the reaction of quicklime with water, which involves more water and

produces a wet hydrate in form of a putty or plastic paste.

14

6. Binder

Binder is natural (inorganic) or artificial material that, if mixed with water,

permit the preparation of plastic mixture that hardens to form a solid mass.

Material such lime, gypsum or cement, could bind sand particle or crushed

stones together to obtain mortar.

7. Mortar

Mortar is a combination of binder and other component such as sand, crushed

stones and water to form a paste. Mortars are used because of their capacity to

fill all gaps between masonry material and for their quality of adhering strongly

and hardening to form a whole with the stone or stone.

8. Aggregate

Aggregate is material added to binder to prepare mortar. It can be either natural

such as sand and crush stone or artificial such as crushed brick.

9. Admixture

An admixture is added substance which modify properties such workability of

the mortar mixture that cannot be obtained using basic binders.

15

CHAPTER 2

LITERATURE REVIEW

2.0 Introduction

In July 2008 George Town, Penang have been awarded the title of World

Heritage Site under the category of Cultural Heritage by the United Nations

Educational, Scientific and Cultural Organization(UNESCO) World Heritage

Committee. According to UNESCO World Heritage Committee, George Town has met

the criteria of Outstanding Universal Value (OUV). OUV are a set of value which are

universally recognized as important or as having influenced the evolution of mankind as

a whole at one time or another.

(i) UNESCO agreed that George Town represent exceptional example of multi-

cultural trading town in east and Southeast Asia forged from the mercantile

and civilization exchanges of Malay, Chinese, Indian and European culture.

(ii) George Town are living testimony to the multi-culture heritage and tradition

of Asia, where religions and culture.

(iii) George Town reflect the cultural element from Malay Archipelago, India,

China and Europe which create a unique architecture, culture and townscape

without parallel anywhere in the East and South East Asia, in particular a

range and exceptional of colonial architecture, shop houses, and townhouse.

16

Therefore, Conservation is to preserve and enhance the message and values of

cultural property. These values are systematically assist with setting priorities in

determining the overall restoration methods and to establish the extent and nature of the

treatment. Four (4) aspects to consider as outlined by ICCROM, the material, design

and architecture, quality of workmanship and manufacturing technique and originality

of the layout and construction. Determining the validity of materials from the past that

is not in the record and the technology is important in conservation

Repair and maintenances work always have been the key element in conservation

activity. The lack of technical knowledge in repairing and maintaining the historic

building has become the major problem, because the conservation work will required an

understanding and analysis of building defect during the repair and maintenances stage

The intervention on historic building need to be at minimal and controlled to ensure

minimal loss of its original value. High quality building conservation can be achieve by

following six (6) principle has been highlight by Ellsmore, 2009 explain as :-

(i) Retain cultural heritage significance

(ii) Used traditional technique and material

(iii) Use appropriately experienced and skilled contractor

(iv) Do only what necessary

(v) Retain repair authentic fabric

(vi) Readily identify new work.

17

Therefore the right techniques and conservation method need to be applied in

building conservation. Ahmad A. , 2006 has surggests four key principle that can be

practiced in conservation work in Malaysia,that is :-

(i) Minimal intervention

(ii) Conducting scientific research and laboratories testing

(iii) Documentation of conservation work

(iv) Applying effective method and techniques

In principle, the existing condition should be inspected technically before

commencing any remedial work. Once the condition has been identified, a systematic

decision can be used to tackle the affected condition. Seven (7) approaches can be used

in conservation work. It can be used as individual or combine depending on the project.

The approaches are conservation, preserving, restoration, maintenances, redevelopment,

rehabilitation and consolidation. (Kamal., 2007)

2.1 Traditional Material.

Heritage building materials in Malaysia usual consist of lime, timber, stone and

clay. The understanding of building material nature and accurate diagnosis of defect is

important for historic building conservation. Prior to this, party involves in building

conservation project need to be familiar with building material common use before

going into proper preservation technique.

18

2.1.1 Timber

Historically, timber materials have been use for wall, floor, roof and structural

framing. Timber can be classified into two categories, such as softwoods and

hardwoods. Timber classification depends on the grain, weight and moisture content. In

addition timber has a moisture content of between 12 and 15 per cent. Moisture content

exceed above 20 per cent, will lead to timber failure. Therefore, it is important for the

material to be seasoned and preserved before it being use for building conservation.

Timber seasoning is to increases its strength properties.

2.1.2 Stone

For thousand years, stone have been use in heritage building due to its natural

durability and strength. Traditionally, stone is use for column, exterior walls, staircases,

window framing as well as roofing material. Stone can last for hundred year, however

its tendency to decay in any three kind of weather (vegetation, soluble salts, erosion by

wind and rain), faulty material and workmanship.

2.1.3 Clay

Clay brick are use as structure wall. Usually clay brick are used with lime mortar

and lime plaster to create breathable walls. Breathable wall will allowing ground

moisture to cool down the room. Clay also use as terracotta roof tile, terracotta floor

tile, and clay invert for drain. Furthermore, clay brick dusts are used in lime mortar and

lime concrete to add strength property. When cement material are used on clay brick

wall and floor, it will forces ground moisture and salt into brick wall

19

Figure 2.0:- Early stage damage show salts crystals ( (Jenkins G. W., 2012)

2.1.4 Lime

Lime has been use as building and decoration material from decade in Malaysia.

Lime is a product of calcium carbonated which commonly takes the form of limestone,

as found and quarried in lime stone hill and also can be found in coral, sea shells, and

chalk. conversation to calcium oxide take places and better known as quicklime, when

any form of calcium carbonate are burnt at between 850 and 1300 degree,. Lime are

used in wall (lime mortar, lime plaster, lime wash), floor and roof. Figure 1 show the

wall breathable concept. Lime allows natural ground moisture to move up the wall and

evaporates through lime plaster. However if the wall are plaster with cement, the

moisture will be block and cause wall damage

20

.

Figure 2.1:- Moisture evaporation (Jenkins, 2013)

2.3 Traditional Binder

Binder is described as a material that will act as glue when mix with sand and

water to form a fresh plaster, render, mortar or concrete. Traditional binders consisted of

clay, lime and gypsum. These were later complemented by the development of natural

and artificial cements. Lime is the principle binder of most traditional mortars, plasters

and renders. It tends to be neglected in modern building practices, but it is central to

successful maintenances and repair of traditional buildings and natural stonework. An

understanding of lime is essential for anyone working on historic buildings.

21

As explain by (Carlos, 2004), gypsum-based mortar have been used since

ancient time, due to their setting upon addition of water, this type of binder could be

consider to be the first hydraulic binder used since thousand year ago. Carlos also

claims that gypsum plaster was commonly used in Middle East and in Mediterranean

country, especially during the Middle age. Gypsum binders also known as Plaster of

Paris and have been used widely in gothic building in the area around Paris. This type

of binder have low strength and poor durability in humid environment, they however

less sensitive to air pollution.

Historically, the type of lime first used hardened when exposed to air was called

air lime. The Roman civilization have the used of lime in 1st century B.Sc. Callebout et

al 2001, explain that the combination of calcium oxide(CaO) ,silica and alumina after

the decomposition with calcium carbonate(CaCO3) produce calcium aluminates and

silicates, it also have been called natural hydraulic limes. As identified by Mertens,

2009, in addition to natural hydraulic lime, the Roman also has discovered the artificial

hydraulic lime. The artificial hydraulic limes were obtained by mixing lime with

pozzolanic material. Pozzolanic materials contain high reactive silica and alumina.

When it combines with the present of water it generated hydrated calcium silicates and

aluminates, with superior binding or cementing properties. The Romans have used lime

in construction since the last two centuries. Besides, the use of air lime, they routinely

used lime mixed with either natural or artificial pozzolanic material. Over time the

used of lime began to be replaced by high performance artificial hydraulic limes hence

name Portland Cement in 19th century. This trend was certainly due to difficulties

experienced regarding the application of lime mortars, such long setting and hardening

times, especially at very high relative(RH), weak mechanical properties and low internal

22

cohesion as well as high porosity, making lime mortar susceptible to damage caused by

salt crystallization or freezing when water saturated

2.3.1 Mortar

The classification of mortar will provides simplified description according to the

proposed of their application and can be classified in two categories. Those intended to

protected the masonries against climatic or environment action for example render and

plastered, and those whose primary aim is too contributed to the structural stability of

the masonry such as joint bedding and repointing. Mortar can also be classified

according to the binder used. Mortar can be made with lime-based binder and mortar

made with cement-based binder.

Most of mortar forming part of the construction of the historical building and

associate structure has been found to constitute by lime based binder. Material defect

are due to misuse and abuse of material in the conservation of the building. However,

material defect became apparently only after a period of time or through usage. By the

through study of the defect the actual cause can be determine and may be avoid.

Building defect based on material studies will able to assist in the preservation and

conservation of heritage building, resulting in direct saving in expenses, effort in

recitation, repair, replacement and conservation Selection of the best methods and

materials can decreased the defect to occur second time in the future. Through

maintenance, function and condition of the building can be restored and help avoid any

problems that occur as occupant safety endanger.

23

2.4 Lime Mortar Ingredient

Lime is used in building in many different ways. Lime putty mixed with sand to

form lime mortar can be used for bedding masonry and for pointing, rendering and

plastering. For the very fine joint ashlar masonry pure lime putty was sometimes used.

Lime putty can be diluted in water to make lime wash for painting both internal and

external wall. A color wash can be made by adding pigment. Lime putty is mixed with

carefully chosen sand and stone dust to make repair mortar for damage stonework. Lime

also has valuable application for specialist stone cleaning and conservation techniques.

Lime mortar is softer and weaker than the brick which it bonds and therefore

able to accommodate slight movements caused by settlement or temperature changes

without significant cracking. Also, it is permeable and allows evaporation of rising and

penetration damp from within the wall. It is this permeability or breathing, which helps

to keep the building dry inside without a damp proof course or chemical treatments.

In order to understand the techniques associated with lime, it is necessary to

review the lime development chronological, (Krumnacher, 2001). He also found in his

research that the art of using mortar in some form or other is as old as the art of building

or as civilization itself. Evidences of the use of mortar are not only in the older countries

of Europe, Asia, and Africa, but also in the ruin of Mexico and Peru. The remains of

work of these ancient artisans are evidence to us of the enduring qualities of lime mortar

as well as the skill and knowledge possessed by the user. Miller in his work on mortar

states plastering is one of the earliest instances of man`s power of inductive reasoning

24

for when men built they plastered, at first with mud then they found more comfortable

method, and the earliest effort of civilization were directed to plastering.

The revival of lime mortar application for the repair of historic building has

taken place, due to recognition of an unfavorable properties of Portland cement mortar,

including brittleness, high strength, and a thermal expansion coefficient which twice

large than lime mortars and most type of brick and stone. Portland cement have low

porosity and large amount of small pores, might hinder water movement in masonry and

cause damage due to the accumulation of moisture behind cement layer or to

evaporation and deposition of salt in adjacent stone or brick. Soluble salt such as

calcium sulphates and sodium salts might be present in Portland cement mortar, which

can leach out over time. However, Lime mortar has a low efflorescence potential due to

its relatively high chemical purity. It also have the advantage of allowing limited

movement within the mortar joints and can undergo autogenously healing due to

dissolution and precipitation process, and its important that lime mortar being softer

and more porous than masonry, and act as a sacrificial substrate water evaporation and

decay from soluble salt crystallization.

There are two basic types of lime, hydraulic lime and non-hydraulic

lime(hydrated lime) based on the hardening mechanisms, Ngoma, 2009, both can be

used as either wet putty or dry powder. The term hydrated is often used when referring

to lime and there is sometimes confusion about the differences between hydraulic lime

and hydrated lime. Hydraulic refer to type of lime which set partly due to a chemical

reaction with water. They can therefore harden even underwater. Non-hydraulic limes

25

require the presence of air in order to set and will not harden underwater. The term

hydrated simply refer to any type of lime, hydraulic or non-hydraulic, which has been

slaked. The term hydrated lime and slaked lime mean exactly the same thing (Ashurst,

1988)

2.4.1 Hydraulic Lime

As identified by Torraca, 1981, hydraulic lime includes natural hydraulic lime,

natural pozzolana and artificial pozzolana. Natural hydraulic lime is the result from

burning of marl limestone, Natural pozzolana, is the result of material mixture of

volcanic origin or certain diatomaceous earth with dissolved calcium hydroxide

(Ca(OH)2).

2.4.1.1 Natural Hydraulic Lime

Sabbioni, 2002, stated that when limestone with a high content of clay is burned,

the clay decomposes at between 400oC to 600

oC and combines with lime at 950

oC to

1250oC forming silicates and aluminates. The lime produced consists of a mixture of

quicklime and cement material that give the ability to set in wet condition or under

water.

Ashurst, 1998, result of hydraulic lime production vary in properties such as

strength, setting time, and quality control level depend to the clay content and type of

clay minerals present in a single deposit. Hence, hydraulicity is the amount of oxide of

silica, aluminum and iron that are present in the limestone. The rate of hardening and

the final strength of the mortar determine by the amount of hydraulically active

26

material, where the proportion of quicklime affect its plasticity and workability

(Bernhard, 1987). Hydraulic lime continues to gain strength after initial hydraulic set

through carbonation.

Lawrence, 2006, concludes that the main controlling factor of the degree of lime

hydraulicity is the silica to lime ratio or cementation index (CI). Table 2.1 show the

hydraulic lime classified based on the cementation index.

Table 2.0: Cementation Index

Type Cementation Index

Feebly hydraulic 0.3-0.5

Moderately hydraulic 0.5-0.7

Eminently hydraulic 0.7-1.1

2.4.1.2 Pozzolana

Bleazard,1998 define pozzolana as non-cementations material which contain

constituents, when this material combine with lime at ordinary temperature and water

will form stable insoluble compound possessing cementing properties. Hence, the

cementing material is defined as adhesive substances capable of uniting fragment.

Based on the finding of Moropoulou, 2004, it can be argued that the pozzolanic

reactivity is not purely due to the chemical content; it is particularly sensitive to the

particle size. Therefore fine ground pozzolana is being considered as more reactive than

course. Pozzolana can be divided into two groups (natural and artificial)

27

2.4.1.2.1 Natural Pozzolana material

Allen, 2003 define natural pozzolana as material formed from a combination of

mineral, consisting silica and alumina with smaller and variable quantities of other

mineral containing calcium, magnesium, iron, potassium and sodium. Natural pozzolana

is very finely divided highly reactive volcanic material. Martinez-Ramirez and

Thompson, 1999 claim that natural pozzolana material does not harden when mixed

with water, the material react with Ca(OH)2 in the presences of water to produces

calcium silicate hydrate, gehlenite hydrate or calcium aluminate hydrates (CAH10,

C2AH8, C3AH6), depending on factor such as curing temperatures, presence of alkalis,

structure, composition and physical properties of the reactive phase.

2.4.1.2.2 Artificial Pozzolana material

Holmes and Wingate, 1997 wrote that artificial pozzolana is the mixture of

calcium hydroxide (Ca(OH)2 combine by heat treatment of natural material such as

clay, shale`s, certain silicious rock or fly ash. For instance, the burning of clay at low

temperature between 600oC and 900

oC destroy the mineral crystallographic structure

resulting amorphous mixture of silica and alumina capable of reacting with calcium

hydrate and form compounds which are similar to those formed in the hardening of

natural hydraulic materials.

The combination of hydraulic set and carbonation produce hydraulic lime set.

Hewlett, 1998 found that hydraulic set is the reaction of anhydrous compounds with

water which yield a new compound (hydrate), which the system changes both chemical

28

and physio-mechanical. The hydraulic set primarily involves the reaction of belite

(2CaOSiO2) with water form calcium silicate hydrate(C-S-H) and Ca(OH)2.

2.4.2 Non-Hydraulic Lime.

According to Ngoma, 2009 hydrated lime is produced from burning a source of

nearly pure calcium carbonate (CaCO3) BS890:1995 stated that at least 85% calcium

carbonate. Usually carbon dioxide is driven off at temperature between 800oC and

1000oC to form calcium dioxide (quicklime). The calcium oxide than is slaked with

water to form calcium hydroxide (Ca(OH2).

Boyton, 1980 and Gibbons 1995 agreed that the slaking process can produce dry

hydrate powder or lime putty, if excess water is use. They also stated that when the lime

is set by drying out then harden wholly by absorption and reaction with carbon dioxide

from atmosphere will return the material back to calcium carbonate(CaCO3). This whole

process is describe in figure 2.1

Non-hydraulic lime (hydrated lime) is commonly being used for conservation

project. It is available either as dry powder or as sticky lime putty. Both have the same

chemical which is calcium hydroxide and calcium oxide (slaking quicklime) in water.

The dry powder is made under carefully controlled condition which ensure that there is

no excess water once slaking is complete, whereas lime putty contain more water than is

necessary for complete slaking.

29

The excess water protects the lime putty from reacting with the air so it can be

stored indefinitely without hardening. This is because storage ensures thorough slaking

and because the lime continues to absorb water into its structure. This increases the

plasticity of the lime allowing a closer contact with the sand grains when it is used for

mortar, enabling a better bond between mortar and masonry. Lime putty should be

stored for at least one month before used, and ideally for at least three months. The

longer it is stored the better and the best work use putty. Lime putty need to be stored in

airtight condition.

Dried lime on the other hand starts to deteriorate from the moment it is made. As

the powder it has a large surface area which when exposed to air, result in partial

carbonation of the lime even before it is used for making mortar. Therefore it cannot

create such effective bond with sand or masonry. Its property improved a bit if it is

mixed with water and stored for at least 24 hours before uses. Mature lime putty give

the best result when being use with traditional material in variety situation.

2.4.3 Sand

Holmes and Wingate, 1997 defined sand as a fine aggregate that refer by specific

name after its nature. Therefore the definition of sand is `weathered particles of rock,

usually high in silica, smaller than gravels and larger than silts, typically size between

0.06mm and 5.0mm. This particle is hard and will not crumble. Beningfield and lees,

1990, found that the choice of the sand in the mortar is determine by its availability in

the neighborhood of building site. The most common used sand are:-

30

a) Relatively coarse-grained, well-graded sand (having wide particle size

distribution) it is mostly found in association with gravel laid down by river.

b) More single sized and finer sand, found in deposited formed of lakes.

c) Marine deposits, both coarse and fine sands, generally lacking in fines.

d) Angular shapes obtained from the crushed rock process.

Sand has a significant effect upon volume stability, durability and structural

performances of masonry mortar. Therefore Carringtong and Swallow, 1996, have

highlighted the role of fine aggregated (sand) in lime mortar are:

1. To counter the shrinkage that takes places with hardening of lime mortar.

2. To assist in crystallization of CaCo3 by forming conduits through which

necessary CO2 can have access and act upon particle of Ca(OH)2 beneath the

surface.

3. To improve the cohesion of the mix, as the lime particle adhere more readily to

the sand than to each other.

4. To act as a filter to increases the bulk of the mass

5. To increase the strength.

Neville, 1995 wrote that the granulometry of fine aggregate will affect the amount

of water required to produce a given flow. Therefore, Sanchez, 1997, aggree that the

lime mortar shrinkage is related to the granulometry of the fine aggregate. Hence, the

larger dimensions fine aggregate, the smaller the shrinkage. Henriques , 2004 conclude

that coarse aggregate in lime mortar lead to lower porosities and capillary water

absorption but give higher mechanical strength. Stefanido and Papayiani, 2005 found

31

that the volume content in mixture has influences on it strength. Lime mortars that

contain sand with size between 0.1 mm and 4 mm give higher strength value.

Lanas and Alvares, 2003 result from studies in factor affecting mechanical behavior

of the lime based mortar, show that the grain distribution of the sand is the most

important attribute in relation to sand characteristic.

2.5 Production of Lime

Lime has been used as a binder for stone and brick, and as plaster or render for

many years. Lime is produced by breaking the stone into lumps and heating the raw

material in kiln. Traditional kilns are normally flare kilns, in which intermittent burning

takes place. Which is the loading and burning are continuous. The minimum

temperature for burning the limestone for lime is 880oc, but for this temperature to reach

in center of the stone lumps and overall temperature at the surface of 1000oc is

necessary. During the burning, carbon dioxide and water is driven off. The burning of

limestone is the first step in the sequence which leads to the setting and carbonation of a

lime mortar, render or plaster. The cycle according to John Ashurst, 1989, can be

summarized as follow:

32

Figure 2.2: The Burning Lime Cycle - Burning, Slaking and Hardening of Non-

Hydraulic Lime (Ashurst, 1989,)

Oates, 1998 and Boynton 1980, agree that the limestone calcination depend to

the limestone shape and its thickness. Large diameter stone required higher temperature

for core dissociation, this is due to the increasing internal pressure as the CO2 gas forces

its escape. Therefore, according Hassibi, 1999, to avoid long residence time in kiln, the

particle of lime stone must be small, with average size of two closed fist.

Result from Moropoulou, 2001 for the effect of limestone characteristic,

microstructure and texture and calcination temperature on reactivity of the produced

quicklime, show that the reactive of the produce quicklime depend on its specific

surface area. large the surface area the more reactive the quicklime. Irfan and Gulsen,

2001 conclude in their study of calcination reaction of ten different limestone are the

CO2driven

off

Exposure to air(carbonation CO2

taken from atmosphere

Ca(OH)2 CALSIUM HYDROXIDE = SLAKED

LIME

Slaked lime may be used in three forms:

Lime putty, Coarse Stuff(putty: sand mix),

hydrated lime(putty dried, ground and

powdered)

LIMESTONE= CaCO3 CALCIUM CARBONATE

BURNT IN KILN AT A

MINIMUM 880OC

CaCO3 = QUIKLIME

CALCIUM OXIDE

Added to water

Process of SLAKING

33

increases of sample weight(dense) causes a significant decreases in the calcinations

reaction rate, and the weight loss of limestone differed from each other, depend on their

CaCO3 content. Hassibi,1999 explain that there are four major factors that determine the

quality of CaO.

a) Chemical Composition of limestone

b) Temperature of kiln during calcination

c) Residence time of lime in kiln

d) The extent of CO2 in the kiln atmosphere.

2.5.1 Lime Slaking

Hydraulic Lime is a slaked lime use to make lime mortar. Hydraulicity is the

ability of the lime to set under water. Slaking is the reaction of quicklime with water. If

quicklime is left exposed to the air it will absorb water from it and air slaked or air

slaked the calcium lumps gradually reducing to powder with an increase in volume.

Swallow and Carrigton, 1995, stated that quicklime needs to be slaked or

hydrated in order to yield workable lime. Hydration(slaking) involves the introduction

of water or moisture to activate the quick lime, having been deprived of water and

carbon dioxide following calcining. When exposed to water, regardless of form

quicklime exhibit a strong affinity for moisture, adsorbing it into pores. As the water

penetrated into the surfaces pores, heat of hydration is triggered. This in turn extract

great internal expansive force in the lime particle and causes it to fracture, shutter and

then disintegrate completely into countless micro particles, either as crystalline dust or

as colloidal suspension, the difference contingent on the amount of water added.

34

According to Ngoma, 2009 the composition of the raw calcium material will

influences the process and method of slaking. Example given by Ngoma, 2009, stated

that wet slaking of impure lime would result in an early hardening of the hydraulic

component present in the impure lime thus reducing the binding capacities of the lime.

Potgieter, 2002 result from investigation the effect of production conditions on the

slaking behavior of lime, show that calcination condition inside the kiln could yield

unslaked lime with various relativities using different rates of reaction with water.

According to Gheevarhese, 2002, chloride ions, which form a more soluble compound

with Ca(OH)2, increase the slaking process, while sulphate ions have the opposite effect

and retarded the hydration process through the formation of a skin of highly insoluble

calcium sulphate ions present in the slaking water.

The effect of slaking rate depends to the chemical variables such as chemical in

slaking water and the quality of lime. It have pointed by Boyton,1980, that slaking

could optimize the performances of the lime being treated to yield a superior quality

lime, wheres at worst the slaking could harm the latent potential of the treated

quicklime rendering it of poor quality. There three type of slaking method as identified

by (Haurie, 2014):-

1) Aspersion

This slake process consist in spreading lumps of quick lime on wooden raft,

rejecting those undercooked and impurities stone. Quicklime than thoroughly

watered and the biggest clods were crumble using shovel in order to

disaggregate the lump and to facilitate the mixture.

35

2) Grande Acqua

In the second method, a pit was dug in the ground roughly 1.2m x 0.6m and 1m

deep. Half of the pits are filled with limestone. Than water approximately 200

liter were poured into the pit. After a few minutes the lime upon contacted with

water will boiled and addition of 400 liter of water were add stirring the lime

putty.

3) Immersion

The third method of slaking consists in filling up 20 liter wicker basket with

limestone and induced it in to water pit up to its complete immersion. Then

immediately removed the basket and left it outdoor while the lime still

hydrating, therefore increasing its volume and temperature in a process that

could last several hour.

2.5.2 Lime Mixing

Krumnacher, 2001 research show that mortar mixing involves technique associated

with high calcium. The techniques were similar to hydraulic mortar, which contain

approximately 20% or more clay within the raw carbonated stone. The research

described a typical mortar and some factor influence its preparation. The common

mortar was made of lime, sand, and water. In order to create a mortar for uniting brick

or stone, worker introduced slaked lime to sand aggregate. According to him, there are

three primary method of mortar mixing predominated:

1. Mixing dry slaked lime powder, sand and water.

2. Mixing wet slaked-lime paste and sand, adding water if needed,

36

3. Mixing pulverized dry quicklime, sand and water, using the mortar while it was

still hot.

Another method mentioned in his research involved the introduction of sand to the lime

during the slaking procedure, which it believed can enhanced the resulting bond

between the lime and aggregate.

The quality of the lime and sand were major factors contributing to the future

performance and properties of the mortar. Where the quality of lime play major role

upon the amount of sand the lime would accept and remain workable. The proportion

and factor involving the suitable bonding between lime and sand are varied in different

places. However, the amount of sand always exceeds the amount of lime. The more

sand that can be incorporated with lime, the better, provided the necessary degree of

plasticity is preserved. For the mortar to become stronger and consolidates more

quickly, when the lime and water are less in quantity and more subdivided.

A critical aspect of mortar and plaster mixing involved the beating or ramming

of the lime and sand mixture. This insured that the sand and lime binder were necessary

to create a workable plastic material for a plasterer or mason. It has been stress that the

key element of mixing was beating plaster or mortar. The mixing purposed is to fully

unite the lime and sand aggregate, therefore filling the void between sand grains with

lime.

37

TIME

COMPRESSIVE

STRENGTH

DRYING

CARBONATION

According to Cazalla, 2000, the most suitable lime and sand ratio is 1:4 because

the mortar is more ridged and with fewer cracks. However, Moropoulou, 2002 suggest

that ratio of 1:3 is the proper ratio for restoration work due to its highest strength.

Krumnacher, 2001, highlight that mixture of mortar need to be allowed to age for

considerable length of time and provide protection to air. This make it set sooner, render

will less liable to crack and hard when dry.

Moorehead, 1986, wrote that once the lime mortar is applied to a building, the

mortar first dry up and then carbonates by reacting with atmospheric CO2. The first part

of initial set is time taken for the mortar to attain sufficient integrity to retain its form

without support. The second part is the carbonation process of portlandite

transformation into calcite. The second part depends on; temperature and moisture

content of the environment, thickness and pore structure of the mortar, surrounding

material and carbon dioxide concentration. During the reaction with atmospheric CO2,

mortar porosity decreases while strength increases.

Figure 2.2: Hardening Process of Lime Mortar (Ngoma, 2009)

38

2.5.3 Lime Storage

Under real life conditions, exposing unslaked lime to ambient atmospheric

condition for varying time intervals during the hot temperature and rainy season.

According to the Potgiater et al,2002 experiment results, air slaking significantly

degrease the slake ability of the lime. Slaked lime when used as building material

(Ca(OH)2), should imperatively be stored in a dry environment with RH

39

large job can be carried out in one or two operation and consistent mortar or plaster will

be available for use as required.

2.6 Lime Plaster

MacDonal, 1989 wrote that the traditional plaster is a mixed bag of quick lime

with water to "slake" the lime. Heat was given off, when lime absorbed water. When the

heat diminished, and the lime and water were thoroughly mixed become lime putty that

was used to make plaster.

The mixture of lime putty, sand, water, and binding material, will provided the

plasterer with "coarse stuff." This mixture was applied in three layers to build up the

wall thickness. The first two coats made up the coarse stuff; they were the scratch coat

and the float coat. The finish plaster, called "setting stuff," contained a much higher

proportion of lime putty, little aggregate, and no fiber, and gave the wall a smooth white

surface finish. (MacDonal, 1989)

Compared to the 6 mm to 10 mm thick layers of the scratch and float coats, the

finish coat was a mere 3 mm to 4 mm thick. Additives were used for various finish

qualities. For example, fine white sand was mixed in for a "float finish." This finish was

popular in the early 1900s. (If the plasterer raked the sand with a broom, the plaster wall

would retain swirl marks or stipples.) Or marble dust was added to create a hard-finish

white coat which could be smoothed and polished with a steel trowel.

40

Then again the used of lime plaster had certain disadvantages. A plastered wall

could take more than a year to dry; this delayed painting or papering. In addition,

bagged quick lime had to be carefully protected from contact with air, or it became inert

because it reacted with ambient moisture and carbon dioxide.

2.7 Lime Wash

As explain by John Ashurst, 1989, lime wash is a traditional surface finish for

lime plaster, limestone and earth walls and it also has been used on brickwork and

timber. Historically, multiple application of lime wash may be found on many historic

building surfaces. The basic principle is lime, to which pigment is add for color and

tallow, linseed oil or casein for more durable treatment.

2.8 Lime Characteristic.

The selection of lime in restoration and conservation of culture heritage is due to

its properties as describe by (National Park Service, 2013)Where lime mortar and lime

plaster are :-

i. Permeable-This means that vapor can pass through them at an almost

imperceptible level, which is a healthier option for inhabited buildings as it

regulates humidity.

ii. Flexible- Stone or brick laid with lime can move as the earth moves through

changing seasons, without cracking the structure or causing instability. There is

no need for expansion joints.

41

iii. Soft-Plasters and mortars should not be harder/stronger than the backing surface

to which they are applied.

iv. Weather proof - Not waterproof, thus protecting the building without sealing it.

v. Deal with moisture effectively- They can hold excess moisture from the

atmosphere in humid conditions e.g. in a shower, without becoming wet and

then release it slowly back as humidity drops.

vi. Reduces greenhouse gas effect- Over its lifetime, due to the cycle of lime

changing from limestone to quicklime and back to limestone again, most of the

CO2 released during the manufacturing process is re-absorbed during the

lifetime of the plaster, thus being close to carbon neutral.

vii. Sustainability- Lime allows the use of low impact foundation.

viii. Breathable- lime allow the building to be more breathable, more breathable

building is a healthier option than sealed building and causes fewer damp

problem.

2.9 Mortar Damage

According to MacDonal, 1989, all material is subject to potential failure, when

plaster dries it relatively rigid material which should last almost indefinitely. Van Hees,

2004, define mortar damage as a form of deterioration of the mortar materials, which

become evident at certain moment such as discoloration to complete loss of cohesion. .

The most important factor that influences the deterioration of building material is

moisture, air pollution biological activity and the present of soluble salts. However,

according to MacDonal 1989, the cause of plaster deterioration may include structural

problems, poor workmanship, and improper curing.

42

2.9.1 Moisture

Plaster applied to a masonry wall is vulnerable to water damage if the wall is

constantly wet. When salts from the masonry substrate come in contact with water, they

migrate to the surface of the plaster, appearing as dry bubbles or efflorescence. The

source of the moisture must be eliminated before re-plastering the damaged area.

Price, 1996 wrote that there are two type of effect cause by moisture, moisture

direct aggressive agent and moisture as medium, which the aggressive agent can work.

The effect of moisture deterioration is largely depending on the mortar porous nature.

Camuffo, 1995, stated that the moisture can penetrated the mortar by three main routes:

1. Condensations of water vapour

2. Capillary rise

3. Rainfall.

Capillary is the main transportation of moisture through mortar due to surface

tension, while condensation depends on the mortar surface temperature. Rainfall is the

source of water to vertical face of structure and it is depending on climate factor and

material. It also can act as an intermediate in weathering carrying dissolved acid gases

to the surface.(Ngoma 2009)

43

Dampness at the foundation level can pick up into the above-grade walls.

Another common source of moisture is splash back. When there is a paved area next to

masonry building, rainwater splashing up from the paving can dampen masonry walls.

In both cases water travels through the masonry and damages interior plaster. Coatings

applied to the interior are not effective over the long run. The moisture problem must be

stopped on the outside of the wall.

2.9.2 Air Pollution

Ngoma, 2009 wrote that air pollution is a dissolves acidic solution in water that

capable to react with calcareous material. Bernal and Lopez 2004 performed a relative

humidity influences and reaction test between sulphur dioxide and calcium carbonated

using laboratory tests at RHs 25-30%,60%,70%,80% and 91%, show there is no

reaction product were detected in the sample exposed to relative humidity between 25%

and 30% for and exposure of 600 hour. However, Van Hees, 2004, stated that the

minimum moisture content in the atmosphere is necessary for the reaction to take

places.

2.9.3 Soluble Salt

(Ahmad.A, 2010), wrote that, salt damage is cause by moisture containing salts

rising up through the capillaries from the ground. The growth of salt crystal within the

pores can generate stresses that are sufficient to overcome the mortar tensile strength

and turn mortar into a powder. Ahmad.A, 2010 wrote that the common causes of salts

attack include:

44

1. Windborne salt spray, usually happen to building located near a sea or river

2. Pollution from nearby factory

3. Biological factor such a bird dropping.

4. Brick clay pudding (salts used in the process leach into the soil)

5. Unsuitable chemical use for cleaning

6. Urine and animal blood.

Princes 1996, state that salt damage is largely attributed to two mechanisms

crystallization of salt from solution, and the hydration of salts. Salt crystallization is a

condition when the salt attacks happen from penetrating from below the surface. The

pressure from the growth of the crystallization process will cause material to crumble.

Efflorescence is known when salt penetrated to the surface and white powder is formed.

According to Ahmad, 2010, Efflorescence is harmless to the masonry, apart from

creating unsightly visual appearances.

Ahmad,2010 identify three factor of salt-induced weathering due to geographical

location, building material and cleaning regime. Pombo,1999 also mention that

environmental factor can also contribute to accelerating the process of decay.

Arayanark, 2002, suggested that salt weathering occur mostly during hot season, due to

relatively humidity and strong sunlight. This happen due to the large temperature

changes and the increase rate of evaporation trigger more upward water movement in

building.

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2.9.4 Biological Colonization.

Giulia,2004 stated that the damage by microorganisms is not as spectacular in

most cases, and it may be slower than other causes of defect. According to Krumbein,

1993 material colonization due to growth of cyanobacteria, algae. Lichens, mosses or

higher plant is highly correlated not only by environmental factor but the physical

chemical characteristic of the material

2.9.5 Structural Problems

Overloading, Stresses within a wall, or acting on the building, can create stress

cracks. Appearing as diagonal lines in a wall, stress cracks usually start at a door or

window frame or random starting points . Impact of the dead load and live load could

impose a heavy burden on beams, joists, and studs. Even it were built properly, later

renovation efforts may have cut in a doorway or window without adding a structural

beam or "header" across the top of the opening. Occasionally, load-bearing members

were simply too small to carry the loads above them. Deflection or wood "creep"

(deflection that occurs over time) can create cracks in plaster. (MacDonal, 1989)

2.9.6 Poor Workmanship

In addition to problems caused by movement or weakness in the structural

framework, plaster durability can be affected by poor materials or workmanship. Such

as poorly proportioned mix. The proper proportioning and mixing of materials are vital

to the quality of the plaster job. A bad mix can cause problems that appear years later in

a plaster wall. Until recently, proportions of aggregate and lime were mixed on the job.

A plasterer may have skimped on the amount of cementing material (lime or gypsum)

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because sand was the cheaper material. More importantly over sanding can cause the

plaster to weaken or crumble. Plaster made from a poorly proportioned mix may be

more difficult to repair. (MacDonal, 1989)

2.9.7 Improper Curing

Proper temperature and air circulation during curing are key factors in a durable

plaster job. The ideal temperature for plaster to cure is between 55 and 70 degrees

Fahrenheit. However, historic houses were sometimes plastered before window sashes

were put in. There was no way to control temperature and humidity.

When temperatures were too hot, the plaster would return to its original

condition before it was mixed with water, that is, calcined gypsum. A plasterer would

have to spray the wall with water to reset the plaster. If the windows were shut so that

air could not circulate, the plaster was subject to sweat-out or rot. Since there is no cure

for rotted plaster, the affected area had to be removed and re-plastered. (MacDonal,

1989)

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2.10 Restoration of cultural heritage.

2.10.1 Conservation

Conservation is essential to understanding the nation heritage, and preserves the

historic building. According (Harun, 2011) the conservation of heritage building should

meet the test of authenticity in design, material, workmanship and setting. Hence, he

concludes that design and material include the architecture style and construction

technique is considered an important value in building. The original design and

materials contained evident of knowledge which has gone within time, ideas and golden

era of the heritage building. Similarly (Yahya, 2012) stated that conserving historic

building is essential to understanding our nation`s heritage, and preserves the historic

character of older town and cities.

Cultural Heritage define by the UNESCO Convention Concerning the Protection

of the world Cultural and Natural Heritage(1972), as (i)Monument, element or structure

of an archeological nature, inscription, cave dwelling and combination of features,

which are outstanding universal value from the point of view of history, art and

sciences. (ii) Group of building, group of separated or connected building which,

because of their architecture, their homogeneity or their place in the landscape are

outstanding universal value from the point of view of history, art and science. (iii) Sites,

works of man or combined work of nature and of man, and area including archeological

site which are of outstanding universal value from the historical, aesthetic, ethnological

or anthropologic points of view. However, National Heritage Act (2005) in Malaysia

context defined cultural heritage as includes tangible or intangible form of cultural

property, structure or artifact and may include a heritage matter, object, item, artifact,

formation structure, performances, dance, song, music, that s pertinent to the historical

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or contemporary way of Malaysia, on or in land or underwater cultural heritage of

intangible form but including natural heritage. Under the section 67(2), in declaring of

National Heritage Property the potential heritage building need to consider nine(9)

criteria:-

i. The historical importance, association with or relationship to Malaysia history

ii. The good design or aesthetic characteristics.

iii. The scientific or technical innovation or achievement.

iv. The potential to educated, illustrate r provide further scientific investigation in

relation to Malaysia cultural heritage.

v. The importance in exhibiting a richness, diversity or unusual integration of

features

vi. The rarity or uniqueness of the natural heritage, tangible or intangible cultural

heritage or underwater cultural heritage

vii. The representative nature of a site or object as part of a class or type of a site or

object.

viii. Any other matter which is relevant to determination of cultural heritage

significance.

Prior to this heritage building can be categorized as limited resource of

architecture heritage that can be seen in built environments. However, the heritage

building mostly suffer from defect problem, neglected and deteriorate, and without a

proper building conservation the building defect potential for recurrence.

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Awareness of the need for compatible material for the preservation of the

building heritage has resulted in the revival of lime based mortar technology and

application. However, knowledge of the preparation process and procedure influence

the final quality of the lime mortar is limited, due to persists in the conservation

community regarding the most appropriated material for conservation treatment. The

historic building in Georgetown which some aged more than 100 years, therefore they

liable to settlement and movement associated with seasonal changes in ground

condition.

2.10.2 Conservation Concept

Conservation is identified as action taken to prevent decay and manage changes of

historical building. However, the United Kingdom Guidances for practices define

conservation as the means which the true nature of an object is preserved. Moreover

true nature the true nature of an object includes evidences of it origin, its original

construction and the material of which it is composed and information as to the

technology used in manufactured. In short the conservation concept as explain by

Harun, 2011, is preserving the authenticity of the heritage base on the original or

historical evident. Harun, 2011, dispute that The basic principle of conservation are:-

i. Careful recording and research before intervention

ii. Minimum alteration of historic fabrics

iii. Minimal risk of significant loss, damage or uncertainty in performances through

intervention

iv. Reversibility of interventions.

v. Retention of a minimum of the original structure

vi. Distinctive of a minimum of the original structure

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vii. Sympathy in interpretation and sympathy in use

viii. Respect for the quality of place

ix. Preferences for original material and workmanship

x. Longevity in the finished work.

2.10.3 Restoration

Clifton and Frohnsdorff, 1982, wrote that the study of historical building is a

complex matter since every building has undergo its unique set of deterioration

condition dependent on internal properties and external environmental condition. The

deterioration is believed to result from dissolution of the material cementing the grains

of building material together or from disruption of the inter-granular bonds from

increased tensile stresses caused by such process as salt crystallization and thermal

expansion. Van Hees, 2004, found that deterioration of historic building is the result of

combination action of various deterioration processes that may act independently or

jointly, running consecutively or concurrently. The outcome for deteriorated material,

independent of the route by which it attains this state, is the same in that the material

will eventually exhibit loss of intergranular bond. Some form of consolidation may be