FREE Encyclopedia of Building & Environmental Construction, Diagnosis, Maintenance & Repair The accuracy & trustworthiness of every article or Q&A is researched by human experts. See WHO ARE WE?
POST a QUESTION or COMMENT about mold sampling & testing procedures that are likely to produce large errors in mold test reports and in mold contamination conclusions about buildings
Mold test mistakes:
This document describes how to avoid common mistakes people make when trying to find mold and test for mold in buildings, such
as testing only the "black mold" on surfaces or relying only on air tests to screen buildings for problem mold.
These mistakes amount to collecting mold test samples in the wrong place, or failing to collect mold test samples in other important places.
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?
Mold and Indoor Air Quality Test Mistakes: Common Mold Surface Sampling and Other Mold Testing Errors
Looking for Mold in All the Wrong Places
Looking just for "black mold": Sampling the "scary toxic black mold" on drywall low on the wall while failing to observe the light-colored but more
airborne and thus harmful molds such as Aspergillus sp. or Penicillium sp. growing higher and less visibly on the surface. See What mold looks like in a home
Using bad lighting: Sampling the "easy to see" mold and missing the "hard to see" mold without first looking carefully with a flashlight.
Bad choice of test surface: Sampling inorganic surfaces like concrete when nearby organic surfaces like drywall paper or wood paneling are present.
Testing Harmless Particles: Sampling things that are obviously not mold and not harmful particles. See Stuff that is Not Mold
Looking for Mold in All the Wrong Ways
Wrong mold test methods: Relying on screening "mold tests" such as "air tests", mold swabs, or mold cultures, to alone indicate the presence or
absence of a mold problem in a building. None of these is reliable when used in place
of or without a careful and expert visual inspection and each of which has severe methodological errors and variability in results.
Inspecting Easy Areas: Looking only in the easy to inspect areas - such as the living space or attic, and ignoring the crawl space.
Overemphasis of Attics Overemphasizing attic mold - where conditions such as condensation often produce less-problematic Cladosporium sp. molds
which do not as easily move down into the living area. But do not ignore attics completely and especially do not ignore attic knee wall areas
outside bedrooms such as in a cape cod style home.
Under-Inspecting Crawl Spaces: Failing to inspect crawl spaces - where conditions are often conducive to problem mold growth, especially
when people are concerned about or may have found problem mold in other building areas
Ignoring Wall & Ceiling Cavities: Ignoring building cavities - which can, depending on wall or ceiling penetrations and the nature of air movement in a particular
building, contain significant reservoirs of problem mold. Some experts opine that mold in cavities never affects building occupants. Our own field investigation has traced high levels of indoor airborne Aspergillus sp. to non-visible reservoirs in fiberglass
insulation, so I would not ignore this possibility.
Omitting Insulation Ignoring non-visible but significant mold contamination in building insulation. Tape sampling is not useful for
porous materials like insulation. We have devised special methods for screening such substances.
There are lots of other errors and inaccuracies that can confound "testing" buildings for mold, such as relying on air sampling
or cultures alone, i.e. "testing" rather than performing a thorough visual inspection (by an expert who knows where to look), and obtaining
a building leak history.
Classes of Testing or Statistical Errors Applied to Mold or Other Environmental Tests, Inspections, Reports
At ENVIRONMENTAL TEST ERROR TYPES we explain in more detail the classes of testing or statistical errors and how in a practical sense they appy to mold or other environmental inspection, testing, lab and reporting procedures. Type 1 and Type 2 errors are defined along with practical examples taken from building inspection and testing for mold contamination.
Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia
Ask a Question or Search InspectApedia
Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
Note: appearance of your Comment below may be delayed:if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.
Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted. Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca
In addition to any citations in the article above, a full list is available on request.
Daniel FriedmanInspectAPedia.com/sickhouse.htm Daniel Friedman
is a mold/indoor air quality investigator and home inspector as well as a professional
writer in Poughkeepsie, New York. He is
a member of the American Industrial Hygiene Association and the American Society of Home Inspectors.
He presently chairs ASHI's national Standards of Practice Committee and has led ASHI's Education and
Technical Committees as well as serving on ASHI's Exam, and Ethics/Professional Practices
Committees. His poetry has appeared in Emphasis, a national publication of MENSA, and his
non-fiction articles and essays have appeared in The Journal of Light Construction, the Old House
Journal, The ASHI Technical Journal, Progressive Builder and New Shelter. His news reporting and
photography have appeared in the Journal of Light Construction, and
in various newspapers including the New York Times, Richmond Times Dispatch, Richmond News Leader,
and the Poughkeepsie Journal.
In addition to citations & references found in this article, see the research citations given at the end of the related articles found at our suggested
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: info@carsondunlop.com. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
Carson Dunlop Associates provides extensive home inspection education and report writing material. In gratitude we provide links to tsome Carson Dunlop Associates products and services.