Mould growth in HDB environment, singapore

MOULD GROWTH IN HDB ENVIRONMENT, SINGAPORE INDIRA SHITA SIAGIAN A THESIS SUBMITTED FOR THE DEGREE OF MASTER BY RESEARCH DEPARTMENT OF BUILDING SCIENCE NATIONAL UNIVERSITY OF SINGAPORE 2008 Acknowledgement This work could not be completed without supports, helps and encouragement from the following people; Prof Michael Chew, for his support, suggestions, encouragements and guidance during research, Mr Tan Phay Phing, for his suggestions and encouragements, Mr Kumari and Mr Tan Cheow Beng, for their helps, Mr Yip Woon Chong (Head of HDB Maintenance) and Mr Chia Tze Yong (NEA Staff), for the sharing of information All the HDB occupants who had agreed and given permission and information during building inspection and interview sessions, My beloved husband, for his support, love, understanding and encouragement every time I feel down and helpless, My dear little baby Arya, for his smile every time I went home, his presence always puts away my entire burden i Table of Contents Acknowledgements i Table of Contents ii Executive Summary vi List of Figure ix List of Tables x List of Diagrams xii Introduction 1.1 Background of Moulds growth in HDB environment 1.2 Current Topic of Moulds growth in Buildings 1.3 Research Objective 1.4 Research Methodologies 1.5 Scope of Research 1.6 Gap of Knowledge 1.7 Contribution to new knowledge 11 1.8 Thesis Outline 11 Literature Review 13 2.1 Moulds in Building Environment 13 2.2 Effects of Moulds Growth in Building Environment 15 2.3 Conditions for Moulds Growth 18 ii 2.3.1 Moisture and Temperature 19 2.3.2 Moulds Spore and Species 24 2.3.3 Nutrients 30 2.4 Comparison of Moisture Sources in Sub-Tropical and Tropical Climate 31 2.5 HDB Singapore 35 2.5.1 HDB unit Maintenance 2.6 Summary of Literature Review Research Methodology 3.1 Data Collection Process 39 40 42 44 3.1.1 Selection and Characteristics of sample HDB unit 44 3.1.2 Building Inspection 45 3.1.2.1.Visual Investigation 46 3.1.2.2.Measurements in HDB unit 46 3.1.3 Interview with HDB Occupants 48 3.2 Data Analysis 49 3.2.1 Methodology of Data Analysis 49 3.2.2 FMEA Analysis to develop Prevention , Remediation and 52 Maintenance Strategies for Moulds Growth Attack in HDB environment 3.3 Summary of Research Methodology Moulds Growth Cases related based on HDB and NEA data 57 59 4.1 HDB Maintenance Report and Statistical Data Dec 2006- Dec 2007 59 4.2 NEA survey Dec 2006-Dec 2007 60 4.2.1 Drain/scupper in HDB environment 61 4.2.2 Waste and Bulky area 63 iii 4.2.3 Roof area 64 4.2.4 Plants Surrounding 67 4.2.5 Wet Surface inside HDB unit 69 4.2.6 Plants inside HDB unit 71 4.3 Summary Results from HDB unit Inspection and Interview with HDB occupants 73 76 5.1 Building Inspection Data 80 5.2 Interview with HDB occupants 85 5.3 Conclusion 89 5.4 Summary 91 Discussion 93 6.1 Moulds Growth in HDB environment in Singapore: The Case Studies 93 6.2 Causation of Moulds Growth in HDB environment in Singapore 109 6.2.1 High Indoor Humidity 110 6.2.2 Condensation 112 6.2.3 Poor or No existent Maintenance 114 6.2.4 Improper Operation 115 6.2.5 Leaky Building Envelope 115 6.2.6 Uncontrolled Ventilation 116 6.2.7 Plumbing and Drainage Leaks 117 6.2.8 Weather 119 6.3 Identification of Moisture Problems related to mould growth in HDB 121 Environment with FMEA approach 6.3.1 Rooms 124 6.3.2 Water Installation 125 iv 6.3.3 Natural Ventilation 126 6.3.4 Climate and Environment 127 6.4 Prevention and Remediation of Moisture Problems related to 134 Moulds Growth in HDB 6.5 Preventive Maintenance Strategies to Reduce Moisture Problems 160 related to Moulds Growth in HDB environment Conclusion and Future Works 167 7.1 Conclusion 167 7.2 Future Works 170 7.2.1 Sufficient sunlight and fresh air in each room of HDB 171 7.2.2 Non continuous vapor retarders and air barriers 171 7.2.3 Gap of Knowledge of moulds growth to HDB occupants 172 Reference 173 Appendixes 189 v Executive Summary HDB (the Housing Development Board) houses 80-90% of Singapore population The quality of life in the HDB environment therefore needs to be maintained and enhanced One of the threats in HDB environments is mould growth Its effect can be as simple as stains or discoloration on the building material surface However, some effects can be more hazardous than they appear Inside the materials surface, the structural integrity is degraded in several ways - components breakdown, short chain additives degradation, disaggregation of material, corrosion, weakening and dissolution and disruption of layered silicates All of the effect is a result of secondary metabolism of moulds Besides degraded building durability mould growth also affects people’s health Preventing the problem is easier and cheaper than remediation which is also a more challenging process To successfully develop prevention and remediation strategies, it is very essential to understand the nature and the cause of mould growth Therefore, the research objective is to find the cause of moulds growth in the HDB environment and develop various design, maintenance and prevention strategies to avoid mould growth The causations of mould growth (both indoor and outdoor) were found by conducting building inspections and analyzing indoor and outdoor measurements (wind, ambient temperature, RH, surface temperature, moisture content) data and occupant activity vi Interviews with the occupants were also performed to gain more information about mould growth (time recurring, maintenance regularity and activity inside the unit) Prevention and remediation strategies were developed with FMEA (Failure Mode and Effect Analysis) approach With FMEA approach, effect of fault that was caused by mould growth were listed and tracked to the root cause After the root causes were thoroughly listed, then prevention and remediation strategy were designed The maintenance strategies to prevent mould growth were also developed During building inspection, 58 mould growth cases were found in Singapore They were mostly found in residential areas that were close to industrial areas, such as Yishun and Jurong West According to building inspection results, environmental conditions when the moulds growth was found was in ±30°C ambient temperature, 75% indoor RH, 20-25% moisture content in each contaminated surface, and ±24°C surface temperature with 0m/s indoor wind Most of the infected HDB units were found 0-10 years old The contamination area was mostly found in bathroom and bedroom The most common causations of mould growth that were found were wet surface (25.86%); high indoor moisture problems (20.69%) and leak plumbing problems (15.52%) Wet surface were present mostly because of plants watering, ponding water, air conditioning water tray and trapped water High indoor moisture was often enhanced by a large number of occupants, plants, pets, an open aquarium, microclimate condition, cooking without lids, and indoor laundry Leak plumbing is obviously as a result of faulty plumbing or ageing (corrosion) vii The main common causations of mould growth can be prevented by developed design, prevention and remediation and prevention maintenance with help of FMEA approach In design terms, limiting the number of plants inside, allowing sunlight and air movement coupled with maintain the temperature and RH in healthy and comfort range will help to avoid and decrease mould growth In several rooms with obvious excess moisture, exhaust fan should be installed In the same way, prevention technique can help such as: providing a canopy, repairing cracks or holes and applying adequate waterproofing and insulation High indoor moisture problems were more related to an occupant’s living habits Therefore, the avoidance methods were more related to habits and maintenance parts Good practices for operation and maintenance are crucial for efficient mould growth avoidance Limitations of plants, number of occupants (250 square feet of living space per person (Minnesota Extension Service 1994), put laundry outside and installing cooker hoods are all examples On the other hand, leak plumbing problems were much influenced by design and construction Improper fall and materials selection were often led to leakage Ageing (corrosion) problems were only able to be detected in regular maintenance However, clogging sometimes was caused by occupants Most of HDB occupants that were interviewed not realize that the mould reappeared after it’d been cleaned It is because the HDB occupants don’t realize the danger of the stains that keep occurring in their units, so they are less likely notice and/or check for them viii List of Figure Figure 1.1 Several areas that are attacked by moulds growth Figure 1.2 Indoor environment especially in wet area are subject to be attacked by moulds Figure 2.1 Life cycle of a decay fungus 15 Figure 2.2 Moulds growth on the inner surface of external wall 17 Figure 2.3 Moulds rotting timber roofing 17 Figure 2.4 Moulds growth on asbestos material on ceiling 17 Figure 2.5 Spore dispersal by wind 25 Figure 2.6 Physical reaction of spore’s wall with rain drops 26 Figure 2.7 Characteristic shapes of water dispersed spores 27 Figure 2.8 Population in Singapore and in HDB Flats 35 Figure 2.9 Population in Singapore and in HDB Flats 36 Figure 2.10 Residential Properties as at 31 March 2006 37 Figure 2.11 Demand for HDB flats 38 Figure 4.1 HDB Maintenance case reported in Dec 2006-Dec 2007 59 Figure 4.2 HDB outdoor environment potential breeding sites 60 Figure 4.3 Broken drain/Scupper in HDB environment based on area 61 Figure 4.4 Broken Drain/scupper types in HDB environment 62 based on NEA survey Figure 4.5 Materials in Waste and Bulky area that potent to be breeding sites 64 Figure 4.6 Moisture sources in Roof Area 66 Figure 4.7 Safest distance between tree and buildings 68 ix Strang, J.J.K and Dawson, J.E., 1991 Controlling Museum Fungal Problems, Technical Bulletin No.12 Canada Conservation Institute (CCI), Ottawa, Canada Tobiasson, W., 1994 Chapter 16: General Considerations for Roofs In Moisture Control in Buildings Editor: Heinz R.Trechsel ASTM Trehun Associates Pte Ltd, undated Bathroom Protection System Available from: http://www.tapl-in.com/7.pdf [Accessed 15 January 2008] Videla, A.H., 1996 Manual of Biocorrosion CRC, Lewis Publisher Viitanen, H., undated Moisture Condition and Biodeterioration risk of building materials and structure Available from: www.bfafh.de/inst4/45/pdf/tfmccond.pdf [Accessed 11 July 2007] Watkinson, S.C, 1994 The Fungi Second Edition Academic Press Wang, J.X and Roush, M.L., 2001 What Every Engineer Should Know About: Risk Engineering and Management New York: Marcel Dekker, Inc Waggener, A.D and Ernest, L.W., Undated Fungal (Mold) Origin and Cause Investigations Available from: www.mma1.com/company/pdf/papers/MMA%20Fungal%20C&O.pdf [Accessed 22 June 2007] 187 Wisconsin Energy Star, 2007 Standard and Guidelines for New Home Construction Available from: www.focusonenergy.com/files/Document_Management_System/Residential_Progra ms/R_EH_GUID_WESHstandards0707v2.pdf [Accessed 12 June 2008] Workplace Safety and Health Division Manitoba Department of Labour & Immigration, 2001 Guidelines For The Investigation, Assessment, & Remediation Of Mould In Workplaces Available from: www.gov.mb.ca/labour/safety/pdf/mouldguide.pdf [Accessed 18 June 2007] Yang, C.S., 2003 Investigating Fungal Contamination in Buildings P&K Microbioloogy Service Yerger, S., 2006 BCRS K9 Mold Detection Service Available from: http://www.bcrsk9molddog.com/ [Accessed 22 February 2008] 188 Appendix A Building Inspection Sheet No Time General Information : Location Age No Occupation Unit Size : : : : Unit Level : Time moulds recurring Maintenance regularity Sick person Age of interviewee Sex : Environment Information Ambient : temperature Indoor RH : Surface temperature : Moisture Content : Indoor wind : velocity Outdoor wind : velocity : : : : Moulds Moulds Location Moulds Size Moulds Color Plants Pets Aquarium Garbage Moisture Sources Ventilation Leakage Ponding water Condensation 189 Appendix B Interview Questions List Of Questions For HDB Occupants Due To Moulds Growth Inspection General Questions Questions Explanations Where is the unit located? Which The location of the unit is important to get floor? information about the environment and surroundings Where is the stain occurred? The location of moulds growth, such as in kitchen cabinet, bedroom wardrobe, and bathroom sealant This is location will lead to room characteristics How long moulds already there? The longest moulds have been occurred the harder to clean up, especially if the contamination area is quite large This will be related to the maintaining and cleaning up method the area In addition, it might harm the occupants’ health Is the mould recurring in certain Recurring during rainy season might a times (during rainy season)? Or symptom of leakage of external wall, or rain several times after cleaning? water penetrating from opening Recurring after several times cleaning might a symptom of false maintenance method or high indoor humidity or high moisture content (Lee (D) and Peart 2001) How is the cleaning up process This will explain the maintenance method conducted? What cleaner is being used? How often? How old is the premises? Ages of the unit show how prone the unit to be attacked by moulds growth Bedroom Questions Explanations Is the window opened regularly or Evaporation, sunlight and fresh air come sometimes? from opening (door and mostly window) By opening the window, fresh air enters the room and recirculates within the room if door is opened This will reduce the risk of moulds growth (Christian 1994) 190 Is the wardrobe/cupboard opened sometimes? is By opening the cupboard/wardrobe, heat will enter inside the cupboard and reduce risk of moulds growth (Lee and Peart 2007) Is the room using fan? Mechanical ventilation helps to enhance the air circulation within the room and also diluted microbial spore that enters from outside (Christian 1994) How old is the age of the furniture The old wardrobe/cupboard generally colder that is affected by moulds? than the new one The moisture content probably high due to lack of heat (Lee and Peart 2007) How far the distant wardrobe/cupboard/desk wall? of the Distant between wardrobe/cupboard/desk from from wall is important to let air flow in between (Lee (B) and Peart 2007) Is the bedroom is adjacent to the bathroom? Is the room kept something wet, for instance wet towel after bath? This is to predict moisture sources and possibility of travel moisture This is will cause a high indoor RH (Lee (B) and Peart 2007) Is the room using carpets? Carpet traps moist, dust and microbial spore (Hasselaar and Van Ginkel 2006) Is there any leaky or water Probably there is an external wall leakage or penetration during rain on the wall rain water penetrates into the room (Focus on or floor near to window? Energy 2006) 10 Is there any leakage from ceilings? Probably there is a plumbing leakage (Focus on Energy 2006) Bathroom Questions Explanations Are the occupants using hot water Using hot water in showering will cause a or cold water? high RH since hot water will absorb more moist (Hasselaar (A) and Van Ginkel 2005) Is the bathroom using exhaust fan? Exhaust fan discharge excess indoor Where is that location? moisture which is accumulated in bathroom and kitchen Location and capacity of the exhaust fan determine its efficiency (Lee (D and Peart 2001) Is the bathroom using shower Shower screen able to zone the bathroom to screen? wet and dry area It is also avoid water 191 splash How long is the approximately taken? shower The longer someone showering the more moisture is produced (Hasselaar, (A) and Van Ginkel 2005) Is there anytime for bathroom to Wet area produces more moisture (Christian be dry? 1994) Is there any leaky or water Probably there is an external wall leakage or penetration during rain on the wall rain water penetrates into the room (Focus on or floor near to window? Energy 2006) Is there any leakage from ceilings? Kitchen Questions Is lid being used during cooking? Is the kitchen using exhaust fan? Where is that location? How long is cooking being held approximately? And how many times a day? Is the laundry kept in the kitchen? Where is the garbage bin? Is there any leaky or water penetration during rain on the wall or floor near to window? Is there any leakage from ceilings? Probably there is a plumbing leakage (Focus on Energy 2006) Explanations Lid reduce moisture that is produced during cooking (Christian 1994) Exhaust fan discharge excess indoor moisture which is accumulated in bathroom and kitchen Location and capacity of the exhaust fan determine its efficiency (Christian 1994) Longer cooking produces more moisture Frequency of cooking also influence of moisture level (Christian 1994) Wet clothes, towels and garments add more indoor moisture Garbage bin is source of microorganism spore Probably there is an external wall leakage or rain water penetrates into the room (Focus on Energy 2006) Probably there is a plumbing leakage (Focus on Energy 2006) Living room Questions Explanations Is the window opened regularly or Evaporation, sunlight and fresh air come sometimes? from opening (door and mostly window) By opening the window, fresh air enters the room and recirculates within the room if door is opened This will reduce the risk of moulds growth (Christian 1994) Is the room using fan? Mechanical ventilation helps to enhance the 192 air circulation within the room and also diluted microbial spore that enters from outside (Lee (D) and Peart 2001) Is the living room having plants? Plants are believed as source of microorganisms spore Having plants also raise up the indoor RH during plants watery (Christian 1994) Is the occupant having pets in the Pets also adds more moisture and source of living room? microorganisms Is the living room using carpets? Carpet traps moist, dust and microbial spore (Lee (C) and Peart 1995) Is there any leaky or water Probably there is an external wall leakage or penetration during rain on the wall rain water penetrates into the room (Focus on or floor near to window? Energy 2006) Is there any leakage from ceilings? Probably there is a plumbing leakage (Focus on Energy 2006) 193 6th 14th Clementi Jurong West Jurong West Eunos Choa Chu Kang Jalan Besar West Coast Bishan Jurong West Jurong East May May May May May June June June May May 8th 3th 4th 5th 12th 6th 6th 4th 12th Jalan Besar January 13th Unit's Level Pungol North Location May Inspect Data room room room room room room 14 room room room room room 11 30 28 12 24 20 7 26 Ages year room Unit Size 3 4 3 No Occupants General Information of HDB Environment Appendix C Bathroom Door sealant Bathroom wall Bathroom floor Bathroom WC Bathroom door sealant Bathroom sealant Bathroom ceiling Bathroom ceiling Bathroom ceiling Bathroom ceiling Living Room Furniture Moulds Location HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant Interviewee 40-45 30-35 30-35 45-50 30-35 35-40 25-30 25-30 25-30 45-50 25-30 25-30 Age F F F F F F F F M F F M Sex 0 0 0 6 Time moulds occur days Y Y Y Y Y Y Y Y Y Y Y Y Recurring /Not 2 2 3 3 2 Maintenance per weeks No No No No No No No No No No No No 194 Sick person Bukit Merah Hong Kah Bedok Bukit Batok Ang Mo Kio Yio Chu Kang Yio Chu Kang Yio Chu Kang Al Junied Woodland Woodland Woodland Marsailing Kranji Choa Chu Kang Clementi Bukit Merah Toa Payoh June June May May June January January January June June May May January January June January June January Sembawang May 7th 11th 7th 15th 12th 14th 12th 6th Ground Level 4th 8th 8th 8th 6th 7th 3th 9th th 7th room room room room room 5 room room room room room room room room room room room room room 23 19 30 29 14 12 18 16 18 21 4 15 22 13 17 6 5 3 4 Bathroom ceiling Bathroom ceiling Bathroom ceiling Kitchen cabinets Door sealant Kitchen cabinets Bedroom Cupboard Bedroom Door Kitchen cabinets Door sealant Bathroom wall Bathroom floor Bathroom WC Bathroom door sealant Bathroom sealant Bedroom wall Bathroom sealant Bedroom wall Bedroom HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant 45-50 35-40 45-50 30-35 45-50 45-50 40-45 40-45 40-45 45-50 25-30 25-30 25-30 35-40 50-55 45-50 45-50 40-45 40-45 F F F F F F F F F F F F F F F F F F F 0 0 0 2 0 0 0 0 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 2 2 3 3 2 2 2 3 No No No No No No No No No No No No No No No No No No No 195 Bukit Panjang Pasir Ris Yishun Yishun Yishun Punggol North June June January January May May 3th 7th 7th 7th 3th 7th room room room room room room room 3 6 3 2 wall Bedroom wall Behind photograph Kitchen cabinets Bedroom Door Bedroom wardrobe Living room wall Kitchen cabinets HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant HDB Occupant Occupant 25-30 25-30 25-30 25-30 40-45 35-40 F M F F F F 3 0 Y Y Y Y Y Y 3 2 2 No No No No No No 196 Pasir Ris Jalan Besar Clementi Jurong West Jurong West Eunos Choa Chu Kang Jalan Besar Tanjong Pagar January January May May May May June June May Pungol North Location May Inspect Data - 12th 14th 6th 6th 6th 4th 12th - 13th Unit's Level - room room room room room room room - room Unit Size 27 12 24 20 7 26 14 20 Ages year 3 No Occupants Lift's Floor Bathroom WC Bathroom door sealant Bathroom sealant Bathroom wall Bathroom floor Door sealant Bathroom Living Room Furniture Lifts Moulds Location Along the shower screen sealant On floor corner Around the WC seat Corners Along the pipe Floor corner All along the sealant Spots cloe to taps All over the dining table and chairs On floor corner Moulds Size Black and Dark brown Black, dark brown and yellow Black patches Black and brown patches Black patches Black and Dark brown Black patches Black and Dark brown Black patches White Patches Moulds Color Indoor Moulds Cases that are found in HDB environment Appendix D 29.4 30.6 28.7 30.6 28.8 24 24 26 30.6 28.7 28.7 30.6 30.6 28.8 24 24 27.56 Surface Temp °C 28.4 29.4 29.5 Ambient Temp °C 26.2 4.67 15 10.92 10.92 2.52 14 26.2 12.44 Surface Moist % 73.8 64.2 62.6 62.2 70.8 70.8 62.2 72 73.8 71.3 Indoor RH % 70.9 60.5 61 60.5 72.8 72.8 60.5 65 70.9 70.9 Outdoor RH % 0 0 0.1 0.1 0 Indoor wind velocity m/s 0.6 0.7 Moisture Sources Wet Surface High Indoor moisture + Wet Surface Wet Surface Wet Surface Wet Surface Wet Surface High Indoor moisture + Wet Surface High Indoor moisture + Wet Surface Moisture travel from kitchen Wet Surface 197 0.1-0.7 0.4 0.1-0.7 0.3 0.3 0.1-0.7 0.5 0.7 0.1-0.7 Wind velocity m/s West Coast Bishan Jurong West Jurong East Sembawang Bukit Merah Hong Kah Holland Bedok Bukit Batok Ang Mo Kio Yio Chu Kang June June May May May June June June May May June January 8th 6th 7th 3th - 9th th 7th 8th 3th 4th 5th room room room room - room room room room room room room 15 22 20 13 17 11 30 28 4 3 Bedroom Cupboard Kitchen cabinets Door sealant Kitchen cabinets Lift's Floor Bathroom ceiling Bathroom ceiling Bathroom ceiling Bathroom ceiling Bathroom ceiling Bathroom ceiling Bathroom ceiling On the doors On the doors All along the sealant On the doors On floor corner Stain in the middle Stain in the middle Stain in the middle Stain in the middle Stain in the middle Stains close to corner Stain in the middle Black patches Yellow and brown patches Yellow and brown patches Yellow and brown patches Yellow and brown patches Yellow and brown patches Yellow and brown patches Black and Dark brown White and yellow patches Black, dark brown and yellow White and yellow patches White patches 29.2 29 30.6 29.2 29.4 29.4 29.4 24 26 30.6 24 24 27 27 27 27 29.4 29.4 27 27 29.4 29.4 26 28 20 19 2.52 20 26.2 26 25.4 25.6 25.8 25.1 26 18 62.9 62 62.2 62.9 73.8 70.9 70.8 70.4 68 69 71 73 62 63 60.5 62 70.9 70 71 71 70.6 70 70 69 0.2 0.2 0.2 0 0 0 0 High indoor moisture + No ventilation High indoor moisture High Indoor moisture + Wet Surface High indoor moisture Wet Surface Leakage plumbing Leakage plumbing Leakage plumbing Leakage plumbing Leakage plumbing Leakage plumbing Leakage plumbing 198 0.1-0.3 0.1-0.3 0.1-0.7 0.1-0.3 0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.1-0.7 Yio Chu Kang Al Junied Woodland Woodland Woodland Marsailing Kranji Choa Chu Kang Clementi Bukit Merah Toa Payoh Bukit Panjang Eunos January June June May May January January January January June June May June Yio Chu Kang January - 7th 11th 7th 7th 15th 12th 14th 12th 6th 6th 4th 8th 8th - room room room room room room room room room room room room room 22 23 19 30 29 14 12 18 16 18 21 4 6 5 3 Bedroom wall Bedroom wall Behind photograph Lift's Floor Bedroom wall Bedroom wall Bathroom sealant Bathroom WC Bathroom door sealant Bathroom sealant Bathroom wall Bathroom floor Door sealant Kitchen cabinets Bedroom Door On floor corner Behind the cupboard Along shower screen Wall's corner Along the shower screen sealant Corners Around the WC seat Corners Along the pipe Floor corner All along the sealant On the doors On the door Black and Dark brown Black patches Black and Dark brown Green and Yellow patches Green patches Green patches White and yellow patches Black, dark brown and yellow Black patches Black and brown patches Black patches Black and Dark brown Black patches Yellow patches 26 24 29.4 26 29.8 29.8 23.3 28 30.1 29.4 26 24 26 30.6 28.7 28.7 29 28 28.7 29.5 28.5 28.8 30.6 24 29.2 30.6 25 29.2 26.2 20 20 26.2 5.52 17 4.67 15 10.92 10.92 2.52 20 20 73.8 70 70 73 61 60 64.2 62.6 62.2 70.8 70.8 62.2 62.9 62.9 70.9 70.4 70.4 73.7 63 63 71 72 73 72.8 72.8 60.5 62 62 0 0 0 0 0.1 0.1 0.2 0.2 0.7 0.2 0.2 0.3 Wet Surface Condensation Condensation Penetrating damp+closed ventilation Leakage joints/roof Wet Surface High Indoor moisture + Wet Surface Wet Surface Wet Surface Wet Surface Wet Surface High indoor moisture + No ventilation Rain penetration from window High Indoor moisture + Wet Surface 199 0.1-0.7 0.1-0.7 0.4 0.1-0.7 0.3 0.3 0.1-0.7 0.1-0.3 0.1-0.3 Pasir Ris Yishun Yishun Yishun Yishun Punggol North Clementi June January January May May May May - 3th - 7th 7th 7th 3th - room - room room room room 30 3 3 3 Lift's Floor Kitchen cabinets Lift's Floor Bedroom wardrobe Living room wall Bedroom Door Kitchen cabinets On floor corner On the doors On floor corner On the back of wardrobe On the back aquarium On the door On the doors Green patches Black, green and brown patches Black and Dark brown White and yellow patches Black and Dark brown White and yellow patches White Patches 24 24 29.4 24 27 26 27.56 24 28.2 29.4 30.2 29 29.5 29.2 26.2 18 26.2 20 18 12.44 20 73.8 62.9 73.8 70 71 71.3 62.9 70.9 62 70.9 70.4 70 70.9 62 0.2 0 0.6 0.2 0.7 Wet Surface High indoor moisture Wet Surface Condensation Moisture travel from bathroom Condensation High indoor moisture 200 0.1-0.3 0.7 0.1-0.4 0.1-0.4 0.1-0.7 0.1-0.3 Hougang Hougang Hougang Jurong West Potong Pasir Commonwealth Buona Vista Pungol East West Coast Tampines Jurong East Bishan Al Junied Jurong West Jurong East June June May June May May June May May May May May May June Location June Inspect Data Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Ground Level Unit's Level 15 23 25 15 22 30 22 20 11 11 11 Ages of building Pavement Ceiling Drain Scupper Scupper Drain Scupper Floor Floor Ceramic wall Floor Floor Ceramic wall Roof edges Floor Moulds Location On the edge and around sewage plumbing All the pavement On the corner Lines Lines Lines Lines Floor corner Ceramic mortar and edges Ceramic mortar and edges Floor corner Floor corner Floor corner Ceramic mortar and edges Lines Moulds Size Black and dark green Black and Dark green patches Black and Dark green Dark green and Black patches Dark green and Black patches Dark green and Black patches Dark green and Black patches Dark green and Black patches Black and yellow patches Black and Dark green patches Green and Black patches Dark green and Black patches Black patches Dark green and Black patches Black patches Moulds Color Outdoor Moulds Cases that are found in HDB environment Appendix E 26.8 26.2 29.4 28.6 23.8 28 28 29.4 26.8 29 28 28 29.4 23.8 28 28 Surface Temp °C 29.4 28.6 29.8 29.8 29.8 28.6 30.1 29.8 29.8 29.8 28.6 29.8 29.8 Ambient Temp °C 29.8 35.4 26.2 24 23 25 26 26.1 25 10 8.5 10 35.4 10 8.5 Surface Moist % 10 73.3 73.7 68 70 69 71 70 71 68.6 68.6 68.6 73.3 68.6 68.6 68.6 Outdoor RH % 0.1 0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.1-0.7 0.5 0.5 0.5 0.1 0.5 0.5 Wind velocity m/s 0.5 201 Reservoir material with lack evaporation Cold Bridging Broken drainage Broken drainage Broken drainage Broken drainage Broken drainage Leakage plumbing Improper drainage Improper drainage Improper drainage Leakage plumbing Improper drainage Improper drainage Improper drainage Moisture Sources [...]... of moulds growth in HDB environment 43 Diagram 3.2.Q-Map of System FMEA analysis to HDB environment 56 due to moulds growth attack Diagram 5.1 HDB unit type that has moulds growth case 80 Diagram 5.2 HDB unit level that has moulds growth 81 Diagram 5.3 Range of ambient temperature in HDB unit during inspection 81 Diagram 5.4 Indoor RH in HDB unit with moulds growth 82 Diagram 5.5 Outdoor RH in HDB. .. causation and building defects caused by mould growth in HDB environment and find the simple solution to fix and prevent of recurring in the future 1.1 Background of Mould Growth in HDB environment in Singapore Mould degrades buildings durability in several ways, such as discoloration, cracking, corrosion, weakening, and dissolution of materials substrates Moulds grow and degrade almost all building materials,... Plants in HDB surrounding 69 Figure 4.9 Wet surfaces that are found in HDB units 70 Figure 4.10 Stagnant water in the flower pot or plate cases that 72 found in HDB indoor Figure 4.11 Cases of stagnant water found in flower pot plate/tray 73 compare water found in plants Figure 5.1 Map of Moulds Growth cases that were found during 77 building inspection in Singapore Figure 5.2 Location of HDB with Moulds... location of growth causation HDB buildings for in HDB o Visual investigation of visible moulds environment in o Measurement of indoor and outdoor condition Singapore o Identify building materials specification, function and location in buildings o Identify environment condition in buildings, such as relative humidity, sun and rain penetration, temperature, water and air tightness o Interview with HDB occupants... investigate the HDB environment in Singapore due to mould growth, in indoor and outdoor environments (as both are interrelated) In outdoor environments, mould spores blend with other outdoor air pollution When the wind blows, mould spores enter into the HDB unit through the window This obviously will affect indoor air quality and harm people’s health The objective of the research is to find the causation... Growth 78 Figure 5.3 Moisture sources found in HDB unit during investigation/inspection 79 Figure 5.4 Location of moulds growth within HDB unit 86 Figure 5.5 HDB occupant’s age that had been interviewed 87 Figure 5.6 Number of occupants in HDB unit with moulds growth 88 Figure 6.1 Moisture Sources from people activity 111 List of Tables Table 1.1 Research Methodology 8 Table 2.1 Effects of moulds growth. .. temperature on the contaminated surface 83 Diagram 5.7 Range of surface moisture on the contaminated surface 84 Diagram 5.8 Indoor wind velocity inside HDB unit which had moulds growth 85 Diagram 5.9 HDB units’ age those were affected with moulds growth 86 Diagram 5.10 Maintenance regularity in HDB unit 88 Diagram 5.11 Time moulds recurring after cleaning up 89 Diagram 6.1 HDB unit as a system 123... formulated preventive maintenance and remediation for HDB environment in Singapore that were infected by mould growth It started with listing and identifying the root problems of each mould growth cases with FMEA (Failure Mode and Effects Analysis) approach This method was introduced by Nielsen (2002) however in his articles, the approach focus on building in general in sub tropical climate In this thesis,... The quality of its environment has to be maintained carefully Therefore, this research focused in residential in tropical climate to fill in the gap of knowledge 10 1.7 Contribution to the Knowledge Mould growth is a re-curing problem in all buildings including HDB environment The best way to avoid the problems is to avoid mould growth and having a preventive maintenance strategies and remediation method... contributing factors or mould growth in building environment 2 developed the • Identifying the root problems/causes from all mould prevention and growth cases related with FMEA (Failure Mode and remediation Effects Analysis) approach; strategies in HDB Listing all the probable causes of molds growth units based on the in HDB environment unique and Develop the preventive maintenance and distinct mould ... building defects caused by mould growth in HDB environment and find the simple solution to fix and prevent of recurring in the future 1.1 Background of Mould Growth in HDB environment in Singapore. .. Discussion 93 6.1 Moulds Growth in HDB environment in Singapore: The Case Studies 93 6.2 Causation of Moulds Growth in HDB environment in Singapore 109 6.2.1 High Indoor Humidity 110 6.2.2 Condensation... 2.9 shows the percentage of Singapore population living in HDB flats during 1960-2006: Figure 2.9 Population in Singapore and in HDB Flats in 2005-2006 Taken from: HDB annual report 2005-2006: