MayDooley

Kurt, ah yes - but our topic was testing, not building science. What makes you think I'm not interested in building science? But even if building science issues were solved, if Aspergillus or Penicillium, etc., are present, they can thrive just in the unconditioned space of wall cavities. Marc - some kind words for a moldy lady. Thank you - I have things to learn from the more technically oriented guys in the class - Kurt, too. Our goal after all is to make things better for the health of our clients. In fact, I'm still hoping for some specific answers for my post on Paecilomyces in wall cavities. I suspect it may not be uncommon and wonder what the cause could be, though my suspicions are leaning more toward it being present at the time of construction, either in or on building materials or rain during construction - I suspect that maybe no one knows at this time. - May

Mike, yes, of course "mold is everywhere" - but not mold growth in high levels, some of the hidden growth even visible to the naked eye. Whether the moldy material can be removed or cleaned and encapsulated, there is no reason for mold growth to return - unless there is a new water incident. Over the years my best teachers have been my clients and their homes. I've had clients who can point out where they feel dizzy or react in other ways... and there's the hidden mold, and there's the lesson. It's not just particulates but also MVOCs. At this apartment, I found some of the hidden mold by wrapping clear tape around a microscope slide and sliding it under the base molding for examination under the microscope. If high levels of spores were found on the tape, the risk for hidden mold in the wall cavity was high. If there's nothing going on in a wall cavity, there will only be a few stray spores on the tape. For another example, with one remediation job in a crawlspace, the company used a biocide (contrary to my guidelines) in some areas and a lime-based encapsulant in others (which I had recommended). Dehumidification was ongoing. Two years later Aspergillus had re-grown big-time in the biocide-treated area but not in the encapsulated area. When I told an instructor at one of my certification classes a good 10 years ago, I remember saying to him that if I were in charge of assigning funds to research projects, the first money I'd spend would be for least-toxic and effective encapsulants. His response was "The science isn't there" - and I guess it still isn't, except for this one lime-based encapsulant I've found. I don't know if it's "allowed" to tell you the product name but if you google my name you can find your way to it. I have no financial interest in the product but just am glad to have something least-toxic to offer that stands the test of time. Over ten years of recommending this product, I've only had feedback once of Cladosporium growing on it - and that was when there had been subsequent flooding in the basement. Our ancestors got it right with whitewash - which is what I still recommend when someone is sensitive to paint or when the pocketbook is running on empty. Most of my clients care about health, and they don't want to get rid of mold only to bring in pesticides. - May

For almost 20 years I have used a microscope on-site and have detected many areas of invisible mold growth at clients' houses. I wouldn't know how to do a mold assessment without a microscope. Once we know where the sources of growth are, we can talk about remediation. I have a webcam attached to my microscope and provide documentation to the clients. Just last week, I did an inspection while the inspector sent by the insurance company did his. He did the customary air samples and visual examination. I found 4 sources of substantial mold growth he missed -- thus expanding the claim. My client didn't want to paper his walls with satisfactory lab results. He was concerned about his health and wanted the mold growth gone.

Dear friends, Thank you for your input re: Paecilomyces in wall cavities. If this were hot humid weather, we would be able to test for MVOCs, but that will have to wait for the summer. There's NO issue with infection, because the spores are not coming through the walls to room air. Paecilomyces may turn out to be common in wall cavities from the time of construction (or in insulation) - but we don't know that for sure right now. Most wall cavities that I have sampled don't show elevated levels of Paecilomyces - but this house did, in every sample, even in interior walls. The clients have children with serious health conditions. Of course they are concerned... yet they don't want to make a mountain out of a molehill any more than I do. They want to do something proactively while they wait for the summertime gas testing. Improving air exchange (whichever way they plan to do it) is a plus for health, whether or not it is needed for MVOCs. We're just looking for input on the best approach to improving air exchange if MVOCs turn out to be present...which we won't know until the summer. I hope this clarifies things. - May

What can you tell me about Paecilomyces in wall cavities? Doing culture-plate testing at wall cavities with suspected mold contamination from leaks led to control test holes at one house. Elevated Paecilomyces was found in all samples, about 10, even an interior wall cavity. What can explain this? Rain during construction? The house is not in a damp location, is about 12 years old, has no history of roof leaks. Every room was sampled by culture plate testing, and no Paecilomyces was found in any room air sample. Since the stakes are high (gutting/real estate disclosure) and we don't know if this is a serious concern or not, the homeowners prefer to be proactive about possible MVOC infiltration into room air. We are researching positive pressure (ThermaStor unit) vs HRV with dehumidification, with the plan being to do MVOC testing (UL-Air Quality Science) next summer in both rooms and wall cavities. Also planned is to replace electrical receptacles with sealed receptacles to reduce any infiltration of mold gases from wall cavities. The more I sample now in wall cavities, the more I am seeing Paecilomyces - not always, but finding it is also not uncommon. I am questioning whether doing a couple of culture plate wall samples might become part of my routine testing protocol in future days. Incidentally, if the $ for lab fees are ringing up in your mind from all this testing... this is in-house testing with homemade culture plates. I find this approach better for diagnostic purposes. I also work with a microscope on-site. I'm taking 50-60 samples at the average house. Your feedback would be appreciated! --May