Monday, March 05, 2007

Building Research Methodology in the Conservation of the Architectural Heritage

PROCEEDINGS: INTERNATIONAL SYMPOSIUM BUILDING RESEARCH AND THE SUSTAINABILITY OF THE BUILT ENVIRONMENT IN THE TROPICS, 14-16 OCTOBER 2002, JAKARTA, INDONESIA, Pp. 517-527

12University Technology MARA, Malaysia

SUMMARY

Nowadays our tropical environments not only consist of new buildings but also the old buildings. Old buildings have certain building characteristics that are remarkable and unique in their own way. From building materials to window detailing, old buildings portray to the modern world their image as they were first built in past time. For this reason it seems that old buildings also can be categorized as a limited resource of architectural heritage that can be seen in our built environments. Almost all these buildings, of course, suffer from defect problems and need to be restored. There are many types of defects, which can occur in historic buildings. These range from structural to material problems, from concrete to plumbing. Therefore, defects in historic buildings can only be repaired and cured satisfactorily only if the symptoms have been recognised and the main causes have been correctly diagnosed. To achieve these, a proper building research methodology is needed in conservation projects. A step-by-step approach needs to be known and explored during the conservation projects. Before practising building conservation, one, including an architect, engineer, building contractor, planner or anyone who has interest in saving an historic building must have a broad understanding of this field, especially on the methodology of building research. This is, of course, to ensure that any action carried out will not cause any harm or missing of evidence and to prolong the life of a historic building for its utilization now and in the future. This paper is organized into three parts; first, the present scenario of building conservation in Malaysia, the second part focuses on the common defects of historic buildings and the third part explains the methodology of building research in conservation projects.

“Historic buildings are ones that give us a sense of wonder and make us want to know more about people and culture that produced it” (Fielden)

INTRODUCTION

Malaysia has a rich legacy of buildings and monuments with outstanding craftsmanship and architectural value. Together they form impressive historic features and heritage of the past works of man. It is important to conserve and preserve historic buildings because they provide a sense of identity and continuity in a fast changing world for future generations. Building conservation is defined as the practice of keeping historic building intact. The term ‘historic buildings’ normally refers to any building built in the past, which is of historical and architectural significance. Historic buildings can also be defined as buildings that have architectural, aesthetic, historical, documentary, archaeological, economic, social and even political and spiritual or symbolic values. If they have survived the hazards of one hundred years of usefulness, they have a good claim to being called historic. In building conservation, the main concern in carrying out any restoration and preservation work is to retain as much as possible the original character of the building and to protect the building from collapse due to possible danger of defects and deterioration occuring at the building. The onus of keeping historic buildings in good repair must rest in the first place with the owner, but there will be instances where an owner is not liable to, or has declined to attend to repairs to his property with the consequence that the building condition, and hence, its qualities are at risk of being lost. By its nature, this man made heritage is fine and because it is open to decay and deterioration, it is likely to get smaller. Therefore, building conservation demands the desire, dedication and involvement of various expertise and professionals to ensure that historic buildings are well preserved and free from defects and deterioration that can slowly damage and destroy the historic buildings themselves. The need for a building research methodology is necessary and should concentrate on studying the agents of defects and deterioration on historic buildings.

PRESENT SITUATION OF BUILDING CONSERVATION IN MALAYSIA

The history of Malaysia has resulted in a rich architectural heritage of traditional Malay houses, mosques, churches, palaces, clock towers, prisons, Colonial administrative and commercial buildings, institutional buildings and schools, railway stations, hotels and guest houses; Chinese shop houses and mansions, Indian temples and monuments. It is believed that there are more than 37,000 historic buildings built between 1800 and 1948 throughout the country which are worthy of preservation and conservation. Like many other countries which are awakening to building conservation needs, Malaysia faces several problems in dealing with the issue of historic buildings and the two major problems are as follows:
1) The present legislation on historic buildings is not sufficient and suitable to protect such buildings from being demolished and destroyed. Under the Antiquities Act 1976 a historic building or monument aged must be at least 100 years old to be listed or gazetted by the Government through the Museum Department to give protection and encouragement for preservation and conservation. However, many important buildings have not yet reached this age, are not protected, others have been neglected or destroyed.
2) There is no suitable or proper system for documenting and recording the historic buildings in the country. It is important in building conservation to identify the building location, function and owner, classify the buildings into their functions, assist the authority in keeping a record on the buildings for future research and funding, determine and measure building defects, and assess remedial measures. Recently, the Department of Museums and Antiquities, Malaysia has started documenting several conservation projects but the progress of documentation is limited due to shortage of manpower and technical skills.
3) Overall Malaysia still lacks of technical experts and skilled workers in conducting the conservation works to repair and maintain the historic buildings. In accordance with the conservation principle, the practice of building conservation should maintain as much as possible the original building structure and fabric.

Basically, most of the historic buildings in Malaysia use building materials which are easily available locally. Such building materials include timber, stone, brick and plaster. In the care and conservation of historic buildings, understanding the nature of the building materials and accurate diagnosis of defects are most important because prevention is better than cure. Something has to be done to reduce the frequency of defects by choosing the appropriate approaches, methodology, techniques and materials.

COMMON DEFECTS IN HISTORIC BUILDINGS

Some historic buildings in Malaysia are at risk from defects because these buildings are not being well cared for, due to lack of knowledge and high cost of repair and maintenance. Basically, it is very important to recognize and diagnose defects at each building element in historic buildings because there are so many defects that occur at various locations with different types of causes and symptoms. By determining the defects, it is hoped that it could make good economic sense to conserve historic buildings as defects concern society at large due to possible danger such as collapse and loss of use. Study about defects and deterioration in historic buildings is important to minimize the cost of restoration and to protect the buildings from being lost forever. Defects can be repaired satisfactorily only if the causes have been correctly diagnosed. Experience has shown that errors are sometimes made, because it is not possible to obtain all the relevant information, but more often because the symptoms have not been fully investigated or the information has not been correctly interpretted. Information can be obtained from visual inspection of the defects at the surrounding area of the building elements. Always remember that it is better to have more information rather than not enough. Table 1 below gives a good example of defects and places to be checked during an inspection where defects normally occur. Meanwhile the key will briefly describe the types of symptoms that can be found at those locations and causes of the defects.

Key to Table 1:
1) Sulphate attack in brickwork caused by heat and unlined flue and resulting in distortion of stack.
2) Split lead to roof covering caused decay in timber surround.
3) Lichen on north slope of roof caused lead in valley below deterioration.
4) Broken tiles where hit by falling pot and damage to valley below causing wet rot in gutter timbers.
5) Slipped tiles causing water penetration through roof to ceilings area.
6) Water penetration of porous render on gable.
7) Leaves from overhanging tree-blocking gutter caused wet rot in timbers.
8) Blocked off chimney and water penetration, also condensation in flues causing dampness on chimney breasts below.
9) Valley and hopper head choked with leaves caused wet rot in roof timbers.
10) Water penetration of porous brickwork of gable caused wet rot in purlins.
11) Inadequate rainwater outlet from flat roof caused roof floods and decay in adjacent timbers.
12) Cracked asphalt caused water penetration to timbers beneath and wet rot in bressummers.
13) Cracked sill caused water penetration into wall below and decay in skirting and window board.
14) Plinth bridges damp proof course (d.p.c) caused rising damp.
15) Choked airbricks caused inadequate sub floor ventilation and wet rot in floor timbers.
16) No gulley caused overflow from rainwater pipe soaks under house and decay in adjacent floor timbers.
17) Plinth cracked away caused trapping water.
18) Water penetration of stringcourse caused wet rot in floor timbers.
19) Gutter inadequate to take flow from upper pipe caused dry rot in timbers adjacent to damp wall.
20) Cement fillet cracked away and water seepage causing decay in timbers.
21) Wet rot in balustrade and foot of posts caused timber decay.
22) Broken gutter caused dry rot in timbers adjacent to damp wall.
23) Wet rot in cellar window frame and lintel from damp wall.
24) Heap of sand caused damp wall and decay in floor timbers.
25) Damp penetration into house walls from porous contacting garden wall.
26) Slab drains towards wall caused decay in sill and floor timbers.
27) Rusting stanchions caused bursting of stone slab.
28) Water penetration of porous brickwork caused decay of lintel behind.
29) Render fragments blocking gulley caused rot in floor.
30) Wet rot in door caused by poor quality timber not pre-treated and poor maintenance of paintwork and putty.
31) Overflow from water butt soaking wall caused wet rot in sill.
32) Render broken away caused water penetration of brickwork.
33) Water penetration from high ground level caused damp on floors.
34) Water penetration from overflow caused decay in sill.
35) Flat roof not draining and water seepage causing wet rot in timbers.
36) Flat roof not ventilated and condensation on timbers causing wet rot.
37) Overgrown creeper keeping wall damp.
38) Choked hopper head overflowing caused dry rot in valley timbers and timbers adjacent to damp wall.

Since there are various types of defects that occur at almost all the building elements at historic buildings, the table below briefly determines the common types of defects that occur at each building element as follow:

LOCATION & COMMON TYPES OF DEFECTS
External walls
Cracking and bowing.
Crumbling and spalling.
Damp.
Condensation and efflorescence.
Patchy white deposits.
Surface disintegration.
Surface deterioration and discoloration.
Crumbling of mortar.
Extrusion of d.p.c.
Internal wall and partitions
Cracking.
Damp.
Patchy white deposits.
Ground floors
Hollowness and curling screed.
Lifting and cracking screed.
Curling and gaps between boards.
Lifting and arching wood blocks.
Lifting and arching tiles.
Loss of floor adhesion.
Damp.
Upper floors
Collapse.
Timber decay.
Warping and shrinking.
Damp.
Staircase
Collapse.
Timber decay.
Cracking.
Flat roofs
Cracking and splitting.
Blistering and rippling.
Dents and cuts.
Edges lifting and sticky.
Deterioration and corrosion.
Water ingress and ponding.
Pitched roofs
Timber decay.
Spreading and sagging.
Deformation.
Deterioration and discoloration.
Slipping and spalling tiles.
Cracking and splitting of sheeting.
Loosening and rusting of sheeting.
Gutters
Leaking.
Rainwater pipes
Leaking.
Blocked.
Perforated.
Bowing.
Windows
Timber decay.
Deterioration.
Distortion.
Staining.
Discoloration.
Cracking of glass.
Doors
Timber decay.
Deterioration.
Delamination.
Distortion.
Faulty operations.
Timber structure and ironworks
Timber decay.
Deterioration.
Corrosion.
External wall finishes
Flaking and cracking.
Blistering and peeling.
Deterioration.
Algae, lichen and mosses.
Mould growths.
Dirtying and staining.
Lime blooming.
Internal wall finishes
Cracking.
Blowing and pitting.
Loose and falling.
Peeling and flaking.
Discoloration and blistering.
Mould growths.
Dirtying and staining.
Ceilings
Cracking and shrinking.
Loose and falling.
Peeling and flaking.
Damp.
Dirty patches.
Drains and external works
Blocked drains.
Cracking walls.
Movement of top course.
Plumbing systems
Leaking.
Frozen and furring.
Water hammer.
Distortion.
Blocked pipes.
Electricity
Electrical appliances not working.
Faulty wiring.

By determining the types of defects, it is hoped that action can be taken by various expertise to prevent it from happening at an earlier stage in the future.

METHODOLOGY OF BUILDING RESEARCH IN CONSERVATION PROJECTS

The practice of building conservation requires careful attention from building owners, occupiers and the involvement and expertise of various professionals such as town planners, urban designers, conservation architects, landscape architects, quantity surveyors, specialized engineers, building contractors, archaeologist, art historians and antiquities. They may be supported by other skilled personnel such as craftsmen, biologist, chemist and geologist. All this expertise demands a high degree of corporation, teamwork, experience, communication and knowledge of building materials and construction especially when dealing with historic buildings because repair and maintenance work is an expensive item to historic buildings. The correct diagnosis of building defects associated with the correct remedial action and research methodology is the only economic basis for successful maintenance and repair programme. Before the commencement of any conservation work, the methodology of overall process should be designed first. The framework of building research methodology is very important in building conservation projects. The methodology will guide the practitioners on what to do and on what stage is involved in restoration works of the old buildings. The framework of methodology also can be considered as a guideline practice in conservation work. All the processes in each phase are interrelated to make sure the result from diagnosis is applicable with solution for the remedy and specification of works. The methodologies are shown in Figure 2. This paper will present phase 1 and 2 only because they are the most important stages in any conservation work and the process is standard. However, the conservation and repair techniques depend on results of building investigation and the state of conservation project.

Phase 1: Documentation
Documentation is divided into two stages as follow:

Stage 1: Historic evidence
Before embarking on any physical interventions in, or design strategy for a potential conservation project it is essential to assemble all the available evidence on the building and/or site that is to be conserved. Original documentation that may be of interest includes:
1) Original design drawings.
2) Drawings from previous investigations.
3) Historical evidence such as old photographs, old maps and old paintings.
4) Reports from previous investigation or any historical reports.

Stage 2: Measured drawing
Measured drawing or ‘as found drawing’ means a set of line drawings that, accurately and in some detail, delineates the subject building in existing condition. The measured drawing will illustrate the interior and exterior of a building including the structural detail. It will also illustrate the defect areas such as cracks in plaster and the missing elements.

BUILDING CONSERVATIONS PROJECT

Phase 1: Documentation
Historical research Measured drawing
-Old Drawing/map -Existing setting/layout
-Old photograph/painting -Plot changes and alterations
Document field condition

Phase 2: Building Investigation
Visual survey Site test Laboratory test
-Identify building types -Nondestructive mechanical -Sampling and testing
and system and structural test of material
-Identify damage -Chemical analysis
Reveal defect

Phase 3: Diagnosis
Causes of Location usually Symptom of Propose
defect occuring defect remedy

Phase 4: Conservation and Repair
Techniques.
Conservation strategy Principle and ethics Method and techniques
-Authentic -Minimum intervention -Cleaning
-Pragmatic -Authenticity of material -Consolidation
-Economic and design -Reconstruction
-Restoration
-Preservation
Detail specifications and drawings of conservation works

Figure 2: The Methodology in Conservation Projects


Phase 2: Building Investigation
A systematic approach must be made to the whole process of investigation and diagnosing the building problems. There are three stages of investigation that should be taken. They are visual investigation, site test and laboratory test. All these methods will constitute the input data for defect diagnosis as follow:

Stage 1: Visual investigation
The process starts with regular investigation. The core of an investigation is the process of walking through a building to gather and record information based on observation of the finished surfaces and any exposed structure. Identify the conditions of materials, describe the damages or defects in the survey form and plot the area on the plan.

Stage 2: Site testing
The investigator, whether he or she is an architect, structural engineer or material conservator, should always be alert to the sensitiveness of the materials and structure of old buildings. Site testing investigation is an action to identify materials and their condition by using instruments. For instance, to monitor the temperature of environment we may use thermometer. The use of this instrument provides greater accuracy than merely feeling whether the room is warm or cool. The site test is a non-destructive test, which is usually based on detection of the physical properties of the wall or exposed surface. Example of site tests available are moisture monitoring, flat-jack, crack monitoring and load test.

Stage 3: Laboratory test
The materials, sometimes have changes from their original composition that cannot be analyzed by using the naked eye. Although the properties of the materials can be identified through the texture, color and moisture, we cannot guess what the original composition is because the material may be too old and they may have already combined with new elements. A sample of material is taken from the defect area. Only the minimum amount required should be removed and a record of removal must be made. They are several types of laboratory tests. It depends on the stage of conservation project such as to identify the original material and the composition of materials if it is a mixture like mortar and plaster, to find the hardness of bricks and to find the porosity.

Phase 3: Building Defect Diagnosis
There are four main objectives to be achieved in building defect diagnosis based on all the input data in phase 3. They are as follow:
1) To identify the main cause of defects. E.g. movement, expansion, fungus, insect etc.
2) To determine the location of occurrences. E.g. walls, floors, roofs etc.
3) To determine the symptoms of defects. E.g. damp, bulging, cracks, patches, powdering, discolor etc.
4) To suggest appropriate methods of conservation and repair techniques. E.g. cleaning, consolidation, removing, replacing, stripping etc.

Before the specifications of conservation works are suggested, all the visual evidence should be written or located in measured drawing. This is to help the consultants to get a good picture of real condition of the building by looking at the plan and the design strategy can be decided more wisely. The remedy for the conservation or repair works also must be based on the laboratory test to make sure the new materials such as mortar and plaster is the same as the original composition. By knowing the exact cause and symptoms of the building defects, the future maintenance program also can be planned properly.

CONCLUSION

There is no reason why historic buildings if restored in a sympathetic manner, should not become attractive, valuable and desirable assets. If we do not take steps to protect and preserve historic buildings of value, either in their own right or because of the contribution they make to a pleasant townscape scene, they may well be lost, and once lost they cannot be replaced. Historic buildings are very important to the quality of environmental life in every country. Buildings of architectural and historic merit should receive very special attention from various expertise and professionals. Before practicing building conservation, one including architect, building contractor, planner or anyone who has the interest in saving an historic building must have a broad understanding of the field itself. This is of course to ensure that any action carried out during the conservation work is properly performed and is in accordance not only with the building environment but also within the scope of contemporary knowledge of the subject.

REFERENCES

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