Mold consultant Phillip Fry has published a list of ten mold inspection steps that need to be taken to protect a real estate buyer:
- A careful physical, visual inspection of the roof, attic, all interior rooms, garage, basement, crawl space, and the heating/cooling system to find evidence of building defects, maintenance problems, water intrusion, water damage, and mold growth. Such a thorough inspection will take at least one to two hours or more to be thorough and complete.
- During the physical inspection, the mold inspector or environmental hygienist should use a professional moisture meter to scan the entire surface of basement walls and the walls and floors of rooms containing plumbing such as the kitchen, bathrooms, and laundry room.
- All furniture and appliances should be inspected for water damage and mold growth on all surfaces, including the backside and bottom.
- All drapery, rugs, and carpeting need to be carefully inspected for water damage and mold growth. The inspector should do at least one carpeting mold test to submit for mold lab analysis.
- The relative humidity of each room and area of the house (including the attic, basement, crawl space, and garage) should be checked with a hygrometer and recorded in the inspector’s notes. If the relative humidity in a room or area exceeds 70% some or all of the time, such high humidity alone is sufficient to drive big-time mold growth.
- The insides of each heating, ventilating, and air conditioning (HVAC) air supply duct should be carefully inspected for accumulated dirt and mold growth.
- The outward air flow from at least one HVAC air supply should be mold tested (while the system is running on fan ventilation) for five minutes with an air pump and Air-O-Cell or other appropriate testing media, with a pump air flow rate of 15 cubic liters per minute, for a total air sampling of 75 cubic liters (5 minutes multiplied by 15 cubic liters per minute). This HVAC air sample will then be sent to an accredited mold lab for mold species identification and quantification. If a residence or building has more than one HVAC system, test at least one air supply duct register in each separate system. If a building has a serious mold problem, there is often the presence of elevated levels of airborne mold spores in the HVAC system, which often itself is a location and source for toxic mold growth.
- The room air in each of at least three important rooms (such as living room and bedrooms) should be mold tested in the same way previously explained for testing HVAC outward air flow.
- If there is any visible mold growth, an actual physical (“bulk”) sample of that mold growth should be collected for mold lab analysis or mold growth colonies should be taken from the moldy areas with such techniques as Scotch tape lift sampling, sterile swabs, and microscopic slide surface sampling.
- Surface sampling mold tests should be done to collect landed/deposited mold spores for lab analysis from out of the way places such as the top side of ceiling fans, top side of kitchen cabinets, and the top side of door and window trim that are rarely cleaned. Surface sampling often gives a more realistic insight into the degree of mold infestation than air sampling. The inspector should do both surface sampling and air testing for comprehensive mold testing.
According to Fry, following these steps should help you avoid buying a commercial building that has significant, hidden toxic mold growth inside walls, ceilings, floors, attic, basement, crawl space, and heating/cooling equipment and ducts.