Assessing the indoor air quality
In this article, we discuss our most recent project where we were instructed to carry out an assessment of the indoor air quality in relation to selected biological contaminants. The building we were called to assess was a two storey terraced town building which was built back in the 1970’s before being converted into a dental practice.
We evaluated the general state of the building, paying close attention to the extent of contamination and using microbiological analysis, we identified that the building was currently being affected by penetrating damp on the left side of the building above the staff toilet and corridor. Though there appeared to be a damp problem, the risk to health from exposure to fungal spores was considered to be low. In order to ensure the building was safe enough for inhabitation we recommended the necessary repairs to be carried out in order to prevent future deterioration of decorative finishes and fungal growth.
What does a damp and mould investigation consist of?
In order to assess the indoor air quality in relation to biological contaminants, we needed to conduct a mould survey. A mould survey consists of collecting samples of airborne moulds onto Vesta Spore trap cassettes by using a High flow 1600 air sampling pump. We then used a process called moisture mapping to locate moisture within building materials and furnishings. Specialist equipment called a Hydromette HB30 moisture meter was used to carry out moisture mapping.
Results of moisture mapping
Moisture mapping revealed evidence of penetrating damp on the back wall of the customer toilet and surgery 1. There was also evidence of water damage along the internal walls in the ground floor corridor. The root cause of the dampness in these areas is most likely cause by moisture penetration through the wall structure. There were no other signs of damp, water damage or fungal contamination in the other rooms on the ground floor.
Moisture mapping also revealed significant evidence of penetrative damp on the ceiling on the first floor, in close proximity to the roof drain. The boxes stacked in the corner of the room revealed elevated levels of moisture and fungal contamination. Our surveyor believed that the root cause of this fungal contamination was a leak through the roof and via a hole in the drain pipe.
In order to address the dampness in the building, we recommended the owners to treat the walls with water impermeable coating and to line all external walls with plastic panelling. With regards to the leak on the flat roof, we recommended that the boxes are removed from the interior of the building before repairing the roof. Despite the water damage and mould contamination in the building, our assessment indicated that the overall risk to health from exposure to fungal elements was likely to be low.