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MOLD: A COMPLETE GUIDE to TEST CLEAN PREVENT
AIR CLEANER PURIFIER TYPES
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ATTORNEYS and EXPERT WITNESSES
BIBLIOGAPHY ENVIRONMENTAL HEALTH, MOLD, IAQ
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HOUSE DUST ANALYSIS
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VENTILATION in BUILDINGS
How to detect hidden mold in walls, ceilings, floors - making test cuts: This article discusses how, why, when, and where to make wall test cuts to find and test for hidden mold contamination or growth in buildings. The fact that mold is "hidden" in buildings does not mean one cannot find it. We look by context: where do we see leak stains, or where do we see building practices most likely to have produced a hidden leak or moisture problem? Ice dam leaks in walls, hidden plumbing leaks, roof spillage by the foundation, are all common clues that often track to a wet building wall or ceiling cavity and from there to a hidden mold problem which may need to be addressed.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
This article on mold inspection and testing discusses the use of test cuts in building surfaces to explore building cavities for hidden mold. Since even small cosmetic damage to buildings is something to avoid when possible, we also discuss how to decide when a test cut is justified, and now to explore building cavities with the minimum damage.
This document is part of a longer article which describes how to find mold and test for mold in buildings, including how and where to collect mold samples using adhesive tape - an easy, inexpensive, low-tech but very effective mold testing method. (See TEST KITS for DUST, MOLD, PARTICLE TESTS for details).
Also see FIND MOLD in BUILDINGS, HOW TO and see MOLD GROWTH on SURFACES for an index of what mold genera/species are frequently found on various building surfaces and materials, and see Mold Related Illness: Index of Symptoms and finally, for an atlas of building molds and for more microphotographs of building mold samples observed in our laboratory, see Mold Atlas of Indoor Clinical Mold, Pathogens, Allergens & Other Indoor Particles. And MOLD BY MICROSCOPE shows what mold looks like under the microscope.
See MOLD RESISTANT DRYWALL for a discussion of that product type as well as a list of drywall or gypsum board industry standards and drywall product MSDS sheets. Moisture Gradients and Mold discusses the variation in type of mold growth found on drywall or gypsum board at different heights above a wet floor.
This procedure helps identify the presence of or locate the probable sources of mold reservoirs in buildings, and helps decide which of these need more invasive, exhaustive inspection and testing.
Unless a building area is already visibly damaged or moldy, we proceed with as little damage or "invasiveness" as possible. Often no invasive cuts are needed to see into a building cavity. Text and photo illustrations in this section are roughly in order of degree of invasiveness.
Often an experienced inspector who knows where to look, can reach very reliable conclusions about hidden mold with no damage to a property at all. Or we can perform non-damaging invasive inspection such as the careful removal of trim for further inspection.
Use of a bore scope to inspect building cavities
Photos demonstrating use of a hole cutter and drill to explore buildings for hidden mold
How to Find or Test for Inter-ply mold, between layers of building materials
Larger Drywall test cuts to check for hidden mold contamination
Where we have justification to proceed we may cut a 2" x 3" hole in drywall to peer into a wall cavity. This opening, like the plug cut openings discussed above, is trivial to patch in drywall or plaster, but permits a more reliable inspection of the building cavity interior than a borescope. Where damage is already extensive, there is nothing lost, no material to preserve, and a still larger opening may be cut, or multiple openings, in order to confirm the extent of contamination and thus the extent of demolition and mold cleanup needed.
My work plan for this New York City apartment included an expansion of the original scope to cut open the lower drywall around the room where our test cut identified this problematic mold. I asked the remediator to continue removing drywall until there was at least a 24" clear margin of no visible mold.
The result was dramatic - water had run in the steel channel formed by the metal sill plate, and had followed the wall around the apartment, producing a significant reservoir of Memnoniella echinata or "black mold" which needed to be removed. (In case you missed it, it is complete nonsense to assume that "black molds" are always a problem and even more erroneous to include light colored and hard to see molds which often are a more significant hazard in buildings.)
Another "toxic black mold", Memnoniella echinata is particularly toxic and irritating. It's a member of the Stachybotrys family but unlike Stachybotrys chartarum, a sticky spore that tends to stay in its place, M. echinata is more easily airborne and I often find it in the air when it's growing in the building. It's more of a problem than its famous brother.
The photographs provide a second warning: a small amount of mold on the visible side of a wall [Memnoniella wall] may be a clue that there is a much bigger problem inside the wall cavity. In the first photo you are looking into a small 3" x 3" opening I made to see conditions in the wall cavity. Don't do this if at risk people are around as you may be spreading spores in the air.
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