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The Art of inner Wall Sampling I



The following is the first of four articles on the importance of inner wall sampling. This first article expounds on just a few of the drawbacks of air sampling from room air, the final three article installments expounds on the importance of inner wall sampling. Sure, it be helpful for an inspector to sample the air for microscopic spores for several reasons:

1) It is an industry standard.
2) It gives the inspector information on the types and levels of spores in that area of the property for that moment of time when the sample was being taken.
3) It gives the inspector information on the presence or absence of hydrophylic mold spores; these are mold spores that indicated water damage because they require more water for growth than other molds.
4) It lets the client know if toxigenic molds are present in the air being sampled, often this is a major concern of the client.

However, when the report comes back from the lab and shows elevated spore levels, or water indicator spores, or toxic mold spores the inspector who sampled the air will often have no idea of where the mold that produced the spores was hidden If the mold was hidden. If sampling your air for mold spores cannot give clear information on where the mold spores originated, then no clear meaningful advice can be given by the investigator regarding the following questions:

Where the mold was growing?

Why it was growing?

And most importantly, what specific root defects in the building need to be addressed to keep it from coming back after it has been removed? That is right, blindly taking air samples for the sake of taking air samples is very common, but it does not answer the above questions; it typically leaves us to ask more questions than it answers.

Air sampling alone is not adequate, and all inspectors, inspection clients, and Realtors trying to sell moldy properties eventually come to realize that sampling for spores alone gives limited helpful information and creates more questions than it answers.
Even sampling near a wall that has mold in it may not prove effective. Sampling the room air near a wall with mold trapped in it will often not give any indication of the true extent of the problem hidden in that wall. It may not even pick up any unusual spore conditions at all if the spores are trapped in the wall.

Many Realtors have had to ask their home inspector, doubling as a mold inspector, these questions:

1) Your lab report says we have mold spores, but where did they come from?
2) If we filter the spores out of the air but do not get the mold growth that created the spores, then will the mold growth produce new spores once we finish filtering the air and turn our backs?
3) OK, so we have mold spores in the air, more than the outdoor air; what room should the drywall be removed from? It is growing in a wall, right?
4) My buyer backed out of the deal and the seller has to fix a mold problem before he puts the home back on the market. How can the seller fix the problem if the report the home inspector gave me does not even tell me why my seller has a mold problem, or what part of the house it is coming from?

In order to raise fewer questions and answer more questions, mold inspectors should not just blindly sample the air as they often do, but they should also engage in three additional activities often overlooked:

1) The first step is to interview the client about the property's history as it relates to moisture, mold, humidity, and health issues that appear to be related to time spent in the property.
2) Second, perform a detailed, time-consuming visual mold inspection focusing on often overlooked visible evidence of mold, moisture, and humidity issues. Many home inspectors and even mold inspectors are not qualified and experienced to do such true mold inspection that can take 2 or 3 hours, just like a traditional pre-purchase home inspection.
3) Third, if hidden mold is suspected in a water-damaged wall, then sampling inside that wall is a logical step.
Information on mold inspection methods and client interviews can be found on other areas of this website, so click here to see more details on the importance of inner wall air sampling for mold spores.