Photos of red molds & yeasts in buildings - how to find & recognize mold on building surfaces
What red mold and red yeasts look like growing on building indoor surfaces
Photographs of red mold & other molds of various colors and textures in buildings
Photos of red & other colored mold contamination inside wall cavities and in insulation
Questions & answers about red mold growth & yeasts in buildings
Photographs to Help Identify Mold in Buildings -
What red mold or yeast looks like in a home or other buildings
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What red mold looks like in a home or other buildings
Identification Photographs of Red & Orange Molds & Yeasts in Buildings
Red mold and red yeasts can be easily seen on building surfaces, especially on the exposed or inner wall-cavity side of drywall in buildings that have been exposed to wet or flooding. Two common indoor red or orange molds include Aspergillus versicolor and the yeast Rhodotorula. But red molds and yeasts 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.
What does red mold or red yeast look like on indoor building surfaces? 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.
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.
Red mold (actually a yeast), orange mold, on this wall to wall carpeting surrounded by more-obvious black mold.
This red, orange, and tan mold was growing in spotty colonies on
the grade-level floor of this building which had been exposed to high humidity. The carpet had not been wet in this area
but other building leaks were nearby. Aspergillus sp. including some strains of Aspergillus versicolor, and yeasts such as Rhodotorula were present.
Click photo for larger image.
Red and orange molds and yeasts can be hard to spot on some surfaces like this wall paneling because they are so often accompanied by other darker mold growths.
We find red molds and yeasts on the both the exposed and cavity side of drywall, on wall paneling, on building contents, on carpeting, on vinyl flooring, and on some other building materials.
We do not usually find red molds or yeasts alone, and in these photos you'll see that other mold genera/species are also present.
Red Mold/Yeast in a wall cavity: Red mold, such as some strains of Aspergillus versicolor, and red yeasts may form Important mold reservoirs inside building cavities. You won't see them without making a test cut in the right place. We decide where to make an invasive test cut by studying where leak or moisture problems have been or are likely to have been on a building.
This photo shows the hidden interior side of drywall on the test cut we made using the hole saw shown at the top of this page.
The red material shown on the drywall paper in this photo was a yeast which accompanied toxic mold which we confirmed was present in this wall cavity. It doesn't look like much on this little 2" round plug, but the entire wall cavity interior was contaminated with this (and other) molds and yeasts.
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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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