How to Find and Test for Mold on or Behind Wall Paneling InspectAPedia® -
How to find hidden mold contamination on or behind building wall paneling
When is it appropriate to pull off wall paneling to look for hidden mold?
Guide to finding hidden mold reservoirs in buildings
Moldy wall paneling may look clean on the room side but be very moldy on the hidden wall-cavity side.
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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.
This document 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.
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.
Hidden Mold Behind Paneling in Bathrooms and Basements
While we do not recommend wholesale demolition of rooms where there is no visible external mold,
if an area has been wet by leaks or flooding, and where paneling covers walls (or ceilings) it is common
to find problematic mold growth behind paneling even if it looks quite clean on the exposed or room side.
Some careful removal of sample panels in the most-suspect areas (most exposed to moisture or leaks)
can disclose a hidden mold problem in a building.
If initial exploration for hidden mold shows what may be a large area of mold, say 30 sq .ft. or more
of moldy surface, work should stop for professional evaluation and to avoid spreading moldy dust
throughout the building.
All mold investigation work, demolition, and cleaning should be performed using the appropriate
protective equipment.
Remove bathroom paneling to expose hidden mold:
The photo above shows an extensive mold colony found growing on the face of drywall which had been
covered by wainscot paneling in a bathroom. More mold growth was on the hidden side of the paneling itself.
None of this mold was visible on the exposed bath surfaces before I pulled off this panel.
Why did I pull it down?
There was evidence of a history of prior leaks in building walls and wet floors in this area.
Superficial cleaning and a "cover up"
installing new paneling was all that the building manager thought was required. Unfortunately it led to a greater cost
later to properly demolish and clean this area.
Remove basement paneling to expose hidden mold:
In this photo of me pulling open the edge of basement paneling more than 20 years ago, we found that a large mold colony
had been generated on the drywall surface hidden behind the wood paneling.
Forty years previously, and 20 years before this inspection photo was taken, a single event basement flood had occurred.
The owners had pumped out water and dried the basement within a few hours of the event.
There was almost no discernable clue on the
exposed side of the paneling itself. Yet because the wall cavities themselves were not opened at the time of the flood,
hidden surfaces and materials stayed wet long enough to initiate a large fungal colony.
It appears that once the
mold colony was established, periodic elevations in basement humidity were enough to keep the mold colony happily
growing along.
One of the home's occupants who grew up in this home developed severe asthma.
She told me that if she simply stood at the top of the basement stairs above this room
she would have an asthma attack.
Warning notice
Guidelines defining what's a "large amount" of mold and what's reasonable for a
homeowner to handle have been published by several states including New
York and California. Links to some key documents describing mold cleanup and mold remediation procedures
are at InspectAPedia.com/sickhouse/action.htm#clean.
People who
are allergic, asthmatic, infant, elderly, immune-impaired, etc., should not disturb mold and should
not be in the area where mold remediation is being performed. Consult with your doctor, health
department or other professional before tackling this job yourself.
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Additional technical contributors & reference sources for this article are listed below.
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Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
Kansas State University, department of plant pathology, extension plant pathology web page on wheat rust fungus: see http://www.oznet.ksu.edu/path-ext/factSheets/Wheat/Wheat%20Leaf%20Rust.asp
"A Brief Guide to Mold, Moisture, and Your Home",
U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
Allergen Tests in Buildings advice about how to test, what to look for, in evaluating the level of dog, cat, or other animal allergens in a building
"IgG Food Allergy Testing by ELISA/EIA, What do they really tell us?" Sheryl B. Miller, MT (ASCP), PhD, Clinical Laboratory Director, Bastyr University Natural Health Clinic - ELISA testing accuracy: Here is an example of Miller's critique of ELISA
http://www.betterhealthusa.com/public/282.cfm - Townsend Letter for Doctors and Patients
The critique included in that article raises compelling questions about IgG testing assays, which prompts our interest in actually screening for the presence of high levels of particles that could carry allergens - dog dander or cat dander in the case at hand.
http://www.tldp.com/issue/174/IgG%20Food%20Allergy.html contains similar criticism in another venue but interestingly by the same author, Sheryl Miller. Sheryl Miller, MT (ASCP), PhD, is an Immunologist and Associate Professor of Basic and Medical Sciences at Bastyr University in Bothell, Washington. She is also the Laboratory Director of the Bastyr Natural Health Clinic Laboratory.
Allergens: Testing for the level of exposure to animal allergens is discussed at http://www.animalhealthchannel.com/animalallergy/diagnosis.shtml (lab animal exposure study is interesting because it involves a higher exposure level in some cases
Allergens: WebMD discusses allergy tests for humans at webmd.com/allergies/allergy-tests
Animal Allergens: Dog, Cat, and Other Animal Dander - Cleanup & Prevention Information for Asthmatics and regarding Indoor Air Quality.
Recognizing Allergens: What various indoor allergens look like - identification photos to help identify pollen, dust mites, animal dander, toxic or allergenic mold - Common Mold and other Allergens, Irritants, Remedies & Advice
Rodent control issues, including dander, fecal, and urine contamination of Buildings and Building insulation are discussed at our
Associations: Sick House, Sick Building, SBS - Air Quality, Government, Private Associations and Information Resources
Atlas of Clinical Fungi, 2nd Ed., GS deHoog, J Guarro, J Gene, & MJ Figueras, Centraalbureau voor Schimmelcultures, Universitat Rovira I Virgili, 2000, ISBN 90-70351-43-9 (you can buy this book at Amazon)
Atlas of Indoor Mold, Online Clinical Mold Atlas, Toxins, Pathogens, Allergens and Other Indoor Particles - Medical Health Effects of Mold (separate online document)
Black Mold that is Harmless Photos of recognizable, usually harmless black mold on wood, bluestain, ceratocystis, ophistoma
Building Floods: quick steps after a building flood or plumbing leak can prevent costly mold contamination
Classes of Mold: what types of cosmetic, allergenic, or toxic mold are a problem? Can mold be cleaned-up successfully?
"A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
"Disease Prevention Program for Certain Vegetable Crops," David B. Langston, Jr., Extension Plant Pathologist - Vegetables, University of Georgia (PDF document) original source: www.reeis.usda.gov/web/crisprojectpages/209797.html
"Disease Prevention in Home Vegetable Gardens,"
Patricia Donald,
Department of Plant Microbiology and Pathology,
Lewis Jett
Department of Horticulture, University of Missouri Extension - extension.missouri.edu/publications/DisplayPub.aspx?P=G6202
Fifth Kingdom, Bryce Kendrick, ISBN13: 9781585100224, is available from the InspectAPedia online bookstore - we recommend the CD-ROM version of this book. This 3rd/edition is a compact but comprehensive encyclopedia of all things mycological. Every aspect of the fungi, from aflatoxin to zppspores, with an accessible blend of verve and wit. The 24 chapters are filled with up-to-date information of classification, yeast, lichens, spore dispersal, allergies, ecology, genetics, plant pathology, predatory fungi, biological control, mutualistic symbioses with animals and plants, fungi as food, food spoilage and mycotoxins.
OTHER IAQ ISSUES: How To Find and Address Other Indoor Air or Indoor Environment Contaminants Besides Mold
Mold or allergens may not be the only or even the main indoor environmental contaminant. Don't let media attention to mold
cause so much enviro-scare fear that other, possibly more urgent hazards go un-addressed.
Ozone Warnings - Use of Ozone as a "mold"
remedy is ineffective and may be dangerous.
Pet control - if you can't say goodbye to your bird, cat, dog, guinea pig, hamster, tropical fish, then limit the
areas they occupy and limit the airflow from that area to sleeping or other areas of the building, use allergenic
bedding, eliminate wall-to-wall carpeting, improve housecleaning including use of a HEPA-rated vacuum cleaner. For more details
see our article Dog, Cat, and Other Animal Dander - Information for Asthmatics and Indoor Air Quality
Rodents, Mice, Squirrel Control - I find high levels of mouse and rodent dander, fecal dust, and urine-contaminated dust in some buildings,
and high levels of these materials in building insulation in those locations. If you have a mouse problem, particularly if mice and their waste (fecals or urine) are contaminating
the building HVAC or building insulation, may need both steps to clean up or remove infected materials and steps to stop an ongoing
rodent problem. If squirrels are a problem, the cleanup needs to include closing off entry openings into the building. Get some
help from a licensed pest control expert.
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