Property damage due to inadequate construction and leaking services

I have been called in to evaluate the extent of water damaged to the newly building designer property in the London area. The purpose of the investigation was to evaluate the extent of the water damage to the property, identify whether the property is contaminated by black water (sewage water), evaluate the levels of mould in the indoor air and evaluate the risk to health to the property occupants. The apartment under investigation of two bedrooms with en suite bathrooms combined kitchen-diner-living room area and several cupboards.

To evaluate the black water (sewage water) contamination I have decided to use microbiological swabbing techniques with the purpose of identified faecal matter bacteria. The most commonly used target organisms I use in these assessments are Escherichia coli and a group of faecal Enterococci. To evaluate the amount of mould spores I have collected several air samples throughout the apartment. I have analysed the collected samples by direct light microscopy in accordance with a publish standards and expressed the results and count of different groups of mould spores per cubic meter.

To start the investigation I have carried out I thorough visual inspection of the apartment. The inspection of the master bedroom did not identify visible water damage to the furnishings or decorative finishes; however area of significantly elevated moisture was detected leading from the adjacent bedroom towards the inbuilt cupboards/toilet. Inspection of the enclosed toilet cisterns identified small leak from the cistern but this is unlikely to be related to the elevated moisture in the floor. The linear nature of the affected area would indicate either fault along service pipe or under floor heating pipe.

C47,master bedroom en suite, toilet cister leak

Investigation in the second bedroom identified significant water damage to the wooden flooring which shows signs of deformation, delimitation and mould rot. Opening of a small section of the floor shows significant mould growth and rot. Approximately half of the rooms flooring shows significantly elevated moisture content. Internal partition walls have elevated moisture content in the lower sections of the walls. The walls around the shower also have elevated moisture content. The room suffers from strong mould odours and high humidity levels. The inspection of bathroom cistern shows significant mould growth including macroscopic fungi, deterioration of materials is significant. Inspection of the cupboard shows elevated moisture content in the flooring, most likely associated with a fault in the under floor heating system.

C47,s6,rooting floor, bedroom C47,s7, bedroom ensuite, behind toilet

The results of the microbiological air sampling show unusually high concentration of mould spores and fragments in the indoor environment. However at the time of the assessment the concentration of mould spores and fragments in the outdoor environment was also unusually high and therefore no certain conclusion can be drawn as to whether the indoor spore concentration is due to internal or external sources. Mould species closely associated with long term water damage such as Chaetomium and Stachybotrys moulds have been identified in the indoor air in relatively small concentration. These species were however absent in the outdoor air and therefore originate in the indoor environment. The surface samples for the presence of faecal bacteria taken from inside the toilet cistern enclosure in bathroom and from under the flooring in bedroom do not confirm the presence of faecal matter contamination.


In my investigation I have concluded that because the apartment suffers from elevated humidity levels exceeding 80%; more than 30% of the total floor area shows signs of water damage; the extent of mould contamination under floors is expected to be in excess of 20-30m2; the extent of mould contamination in internal partition walls in expected to be in excess of 20m2; the presence of strong mould odours and; significant damage and deformation to decorative finishes; the apartment is not suitable for habitation. It is also our opinion that prolonged exposure to mould spores and metabolites is likely to results in adverse health symptoms.

 By Tomas Gabor

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Hi, I have been working in my job as an Indoor Air Quality Investigator for a number of years and decided to share my experience with you. You can find lot of related information on my website toxic black mould
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