Staining could result negative appearance of a building that actually start from a single tiny dots.

2. BIO-FOULING1

3. TYPE OF STAINING ON BUILDING2

4. PATTERN OF STAINING2

5. CLEANING STAIN4

6. Exposed Brick and Concrete Walls4

7. Natural Stone7

8. Tiles10

9. Metal10

10. Glass14

11. Plaster and paint Surface15

12. CASE STUDY : PUDU PRISON, Kuala Lumpur17

13. Building Overview17

14. Methodology of Inspection22

15. Type of Staining on Pudu Prison23

17. Staining and soiling account for the most obvious or conspicuous forms of changes in a building’s appearance. Staining is defined as a mark or discolouration that is not easily removed. The build-up of stains on building surface at a time before it is normal or expected can be termed as premature staining. Staining or premature staining on building surface of new buildings has gained much attention in recent years.

18. Factors that contribute to staining include material, exposure, design, colour, water absorptivity, dirt retention, texture and solubility. Stains form primarily from the surface flow of water (runoff) down the facade. Water brings along dirt particles that is retained on the façade material. When the water dries out, dirt particles that are not washed off manifest as stains.

19. Buildings need to be designed to be more maintainable so that resources used on cleaning and maintenance work may be minimised.

20. BIO-FOULING

21. “Bio-fouling” is a term used to describe the defacement of external and internal surfaces by organic contaminants. It can easily disfigure an otherwise attractive surface.

22. Microorganisms such as fungi and moulds usually cause organic staining on wall, ceiling and floor surfaces. These can have adverse health effects (e.g. mainly respiratory ailments such as asthma, rhinitis, etc) as well as aesthetic implications.

23. TYPE OF STAINING ON BUILDINGS

24. The main forms of defacement that affect property are listed in Table 1.

25. StainingTypeExternalInternalBiologicalAlgaeLichenMouldAnimal excrementMouldCobwebsSlimeHuman soilingPhysicalSootGrimeDampness (seismic/ rainwater staining)Dampness (general)EfflorescenceGraffitiOilRustWater-soluble chemicals such as sulphates causing yellow stains on stoneworkTobaccoGrimeGreaseDampness (tide mark)Pattern (thermal)Hygroscopic saltsGraffitiOilRustWater-soluble chemicals such as sulphates causing yellow stains on stonework

26. Table 1 : Type of staining on building

27. PATTERN OF STAINING

28. According to Diamant (1977), if a wall or ceiling is evenly insulated throughout, the dust tends to be deposited evenly. One of the most annoying aspects of the existence of thermal bridge or irregular insulation of walls and ceilings is the formation of dirt patterns. The reason for this is that air molecules (Brownian movement) are constantly bombarding suspended dirt particles. As hotter air molecules move faster than colder ones, there is a concentration of dirt particle over the colder areas of the wall and ceiling, since they are exposed to different impact momenta in different directions. The particles move slower over cold sections and therefore tend to deposit on these.

29. When the particles finally settle they naturally deposit themselves upon the wall and ceiling areas with the lowest surface temperatures. Thus it can be considered that the distribution of pattern staining is a direct measure of the surface temperature of the wall and ceiling and consequently of the thermal insulation properties of the materials beneath.

30. In the case of an un-insulated plaster boarding and rafter ceiling, lighter lines trace the position of the rafters. If the space between the rafters is insulated by means of glass fibre, while the timber rafters are not, the pattern is often reversed, although it is not as pronounced due to the fact that the difference in temperature between the surface affected is reduced.

31. In the case of wall, the maximum amount of pattern staining is usually found near the ceiling and the floor due to the thermal bridges formed by flooring connections.

32. Pattern staining is also found near corners, but the actual corner itself is usually much lighter than its surroundings as the corner is generally better insulated than the wall surfaces on either side.

33. A further manifestation of pattern staining is the blackening of walls above heating elements, such as hot water radiators or electric fires, and the blackening of patches around electric light bulbs. In these cases, it is difficult to prevent the staining except by the provision of shields to stop the dust particles from alighting on wall and ceiling.

34. CLEANING STAIN

35. Exposed brick and concrete walls

36. Bricks are usually durable materials that age gracefully and require minimal cleaning. Nevertheless, dirt staining and efflorescence di cause bricks to lose their aesthetic value over time. Table 2 shows some cleaning methods for brick walls of various condition.

37. Dirt stains and biological growth could be water blasted to remove them from the brick wall. Efflorescence has to be brushed or scraped off from the surface whenever the salts appear. Brick masonry can generally be cleaned with chemicals in conjunction with water rinsing. Acidic cleaner containing dilute mineral acids such as hydrochloric, hydrofluoric, phosphoric and/ or organic acids such as acetic and citric acids are used to remove heavy soiling from most bricks masonry walls. The cleaning process involves applying the diluted cleaner to the pre-wetted surface and allowing a short dwell period. Chemical and soiling residues are removed by pressure water rinsing. The use of acid should be avoided in cases when steel accessories are incorporated in the brick wall. Bricks with high iron content may also be reactive to acids. Sometimes alkaline cleaners are used to remove soiling on brick surfaces, but the type of chemical cleaner should be selected with care, and then tested on small areas before it is used to clean the whole area. Certain chemicals may cause staining on some types of bricks. Soft bricks are particularly vulnerable to damage from aggressive cleaning methods. Cleaned bricks should be coated with a water repellent sealer to prevent bricks from getting wet.

39. Natural stones may be generally classified into two general categories based on its composition: siliceous or calcareous. The former tends to be more durable and relatively easy to clean with neutral cleaning solutions. The latter is sensitive to acidic cleaning agents and requires cleaning with specially formulated stone cleaners.

42. Mild soap or detergent.

43. Solvent cleaner, e.g. kerosene, turpentine, white spirit.

44. Non-etching chemical cleaner.

45. Wax-based polish cleaner.

46. Abrasive wax.

49. Building overview

50. Pudu Prison was a well-known historical attraction in the Kuala Lumpur city centre, its large area of 8.8ha in Jalan Hang Tuah, Kuala Lumpur, is a prominent landmark in the nation’s capital city. 114-year-old Pudu Prison standing there had been witness how Kuala Lumpur step into a big city.

51. Figure 1 : Location of Pudu Prison, Kuala Lumpur

52. Pudu Jail or Pudoh Gaol, The historic Pudu prison was built and designed in 1891 and completed in 1895 by state engineer and director of Public Works Department, Charles Edwin Spooner. At the cost of RM 138 000 ($320 000), the prison was built in six phases using steel, brick and cement, all imported from British colonies India and Britain.

55. James Douglas and Bill Ransom, 2007, Understanding Building Failures – Third Edition, Taylor & Francis, London

56. Edward A. Noy Revised by James Douglas, 2005, Building Surveys and Reports – Third Edition, Blackwell, London

57. John Hinks & Geoff Cook, 1994, The Technology Of Building Defects, Taylor & Francis, London