What brown, dark brown, even brown-to-black colored indoor mold looks like when found growing on building surfaces
Photos of brown mold in buildings - how to recognize indoor mold problems
Questions & Answers about brown mold in buildings; should you buy a moldy house?
What does brown mold look like when found growing indoors? Brown mold identification photographs - building mold.
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These mold spores and their photographs and examples of materials sometimes mistaken for mold have been collected
in the U.S., Spain, Mexico, France, as well as in other countries where I've studied bioaerosols.
Also see BROWN HAIRY BATHROOM MOLD for a Q&A on the harmfulness of "hairy brown mold" found in a bathroom.
These photos of mold on indoor building surfaces may help you recognize
mold in buildings, recognize probably-cosmetic mold, and recognize stuff that is not mold and does not need to be tested.
Photographs to Help Identify Mold in buildings -
What brown or tan mold looks like in a home or other buildings
Among the 1.5 million mold species, there are a great many that may be found in buildings and that are brown or tan in color. Some of these brown molds, also sometimes appearing black, and commonly found indoors include Aureobasidium pullulans, Taeoniella sp., and even the very common Pithomyces chartarum. Most of these are wood rot causing fungi and they appear where wood framing or building sheathing have been exposed to wet conditions.
Brown mold can be easily seen on building surfaces but it cannot be reliably identified to genera/species without analysis by a qualified aerobiologist/microscopist in a test lab. See Mold Atlas & Particles List for an atlas of building molds and for more microphotographs of building mold samples observed in our laboratory. See our Atlas of Mold Related Illness Symptoms & Complaints for details about specific mold genera/species and their health effects. Also see Mold spores in the Home - a Photo ID Library for detection and identification of mold allergens
on indoor building surfaces.
Identification Photographs of Brown Mold in buildings
Brown mold on plywood roof sheathing in an exposed to
leaks or moisture problems is one of the most common molds spotted by home inspectors.
In this particular attic a sample was collected using our
tape sampling method.
Our lab determined that in this case the brown mold was predominantly Aureobasidium pullulans which is at
most, an allergenic, non-toxic mold. (Often in attics we also find Aureobasidium pullulans which looks about the same, or a little
darker on plywood or framing.)
Very frequently when we are asked to investigate a building where
this condition has been observed, we discover that there is a more serious problem with Aspergillus sp. or Penicillium sp. mold contaminated-insulation - a condition that was missed in the initial investigation.
Inspectors or mold remediators who call for roof replacement in a case where the plywood is not actually
damaged (delaminating) from leaks are overreacting to the "toxic black mold" they think they see, and
they are failing to identify the more serious problem that may be present.
As you can see in
this photo of very dark mold in an attic, in a wet attic these mold groups, which are "brown" in the microscope, can look pretty "black"
on the plywood. As we point out in other comments throughout our website, the public, media, and "mold inspector" focus on "toxic black mold" in buildings
is often unfortunate as it fails to address more serious problems.
Brown mold on Oriented Strand Board (OSB) wallboard in a basement exposed to prolonged wet conditions. This mold was, on lab testing, predominantly Cladosporium sphaerospermum which is at
most, an allergenic, non-toxic mold.
Small colonies of a few square inches each of other more problematic molds and
yeasts were also present.
Remediation included simply discarding this material.
Our brown mold photo at above left was obtained in a flooded basement where wooden paneling had been quite wet.
Brown Stemonitis sp. growing on oriented strand board (OSB) subflooring in an un-finished bathroom, above right, is one of our more photogenic mold species.
Brown Stemonitis sp. mold growing on oriented strand board (OSB) subflooring in a condominium subjected to wet conditions over many months is shown in close ups in our two photographs above. More photographs of white and brown Stemonitis sp. fungal growth in bathrooms are shown and discussed at BROWN HAIRY BATHROOM MOLD and also at Rental Apartment Mold Safety Advice.
At left and below we include additional photographs of Stemonitis sp. details from our forensic lab.
At left is a light gray-brown Stemonitis slime mold or "pipe cleaner" fungus that we collected on tree bark. Though it may occur, we have not found this light gray-brown Stemonitis species in buildings.
At below left is the capillum or "hair net" that holds the Stemonitis spores until the net is ruptured (easily by touch) to release spores.
At below right are Stemonitis sp. mold spores.
Watch out: some brown molds (or molds of other colors too) may be white at some growth stages or may include white components such as their mycelia. See White Mold and see Rental Apartment Mold Safety Advice for some examples of the white colored stage of Stemonitis sp..
Brown fungus growing out of carpeting and floor trim combined with green mold on the exposed surface of drywall were conditions
easily seen, and under which we assumed that the wall cavities were likely to be mold-contaminated in this area.
If you see mushrooms growing out of a building surface it's a safe bet that conditions have been quite wet and there is high probability of additional and substantial hidden mold growth and perhaps rot (and insect damage) in building cavities and in nearby wood structural members or subflooring.
Questions & Answers about brown mold in buildings
Also see BROWN HAIRY BATHROOM MOLD for a Q&A on the harmfulness of "hairy brown mold" found in a bathroom.
Question: I'm looking at a home with mold damage, should I avoid buying it?
I am thinking about buying a house, but has a brown fluffy mold on most of the floor joists, and it looks like the pictures you have of Brown Mold on OSB.
Since taking the joists out will not happen, would it be wise to stay away from this house cost wise? The mold 's brown and fluffy, and I found a few salamanders under there as well. Please help - Skyler
Reply: How to avoid buying a home that ends up under water
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem.
That said, here are some things to consider:
The mold you see may be the tip of an iceberg of bigger mold contamination, leak damage, rot. Finding salamanders in a crawl space or basement are a sure sign that there has been a serious water entry or leak problem. That's why you need a competent, thorough inspection.
I can't say you should or should not buy a house that needs mold remediation or any other repair - but my OPINION is that the relevant questions are?
Does the price of the home reflect the repair work needed?
Will cost of making the house livable price it out of the current marketplace compared with similar homes in the neighborhood?
Do you have the time and energy to manage the work needed, or do you have someone you trust to do it for you ?
If you like the house, its price, and the neighborhood, and if you are willing to handle the repair work needed, you still should not proceed with the purchase before you have a reasonably accurate idea of the extent of repair work that will be needed - that's what can help keep you from getting in over your head and ending up with a house that is "under water".
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Additional technical contributors & reference sources for this article are listed below.
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[1] Field Guide to Mushrooms, Lincoff, Gary H., Carol Nehring, National Audobon Society, Alfred A. Knopf, 2000, ISBN 0-394-51992-2
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.