How to Remove Bathroom Mold & How to Prevent Future Mold Growth in Bathrooms InspectAPedia® -
Mold cleaning and removal advice for bathrooms
When is it necessary to demolish a bathroom to deal with bathroom mold?
Bathroom renovation tips listed here will help mold-proof the bathroom against future problems
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This document gives advice on how to remove & prevent mold in bathrooms, including bathroom renovation tips - easy details that will help mold-proof your bathroom. This article is part of our series:
FIND MOLD in buildings, HOW TO 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 MOLD TEST KITS for DIY MOLD TESTS for details).
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.
Small amounts of mold can be removed simply by cleaning or removing infected materials, something
most homeowners can handle. Use any household cleaner or bathroom cleaner to clean off mold from tile, grout, or other hard surfaces.
You can use a fungicidal cleaner such as the product shown at left if you like, but any household cleaner, even plain soap and water will do fine. It's the cleaning that is important, not surface infection, when we're removing mold. Preventing future mold growth can be assured more reliably by fixing the conditions that invited it in the first place, rather than by relying on mold killing sprays.
Bleach solution to clean off mold is not necessary - the object is to remove mold, not kill it. But since cleaning off surface mold may leave stains in the tile grout, you might prefer to bleach that surface anyway. If you are going to use bleach to clean mold anyway, perhaps for cosmetic reasons, see MOLD CLEANUP with BLEACH for more advice.
You may find that moldy caulk just won't clean up - you'll need to cut and remove the old moldy caulk, clean the tile or tub surfaces thoroughly (we use alcohol), and re-caulk with a mold-resistant bath caulk. You may read that your bathroom caulk is "mildew resistant" which is funny since there is no mildew in buildings - mildew (a sub group of the larger group of molds) grows on living plants - unless you are growing grapes in the bathroom, it's mold, not mildew. But forgive the sloppy language and buy mildew-resistant caulk anyway.
Guide to Renovating & Improving Bathrooms to Avoid Future Mold Growth
At Bathroom Vanity Cabinet Mold we explained how water running under or behind a bathroom vanity or sink base can cause hidden mold growth on the vanity back, under-side, and on the wall behind the unit. Our two photographs just below show mold that was found on the chipboard vanity base back surface and on the drywall behind the vanity.
The drywall behind the vanity looked bad enough that we explored the wall cavity to be sure that additional demolition above the moldy drywall itself was not needed.
Here we show the underside of the bathroom vanity cabinet. At the top of the photo, in particular, you can see that the chipboard vanity side was swollen and damaged by water that had passed along the bathroom floor.
We decided to toss out this vanity base rather than try to clean and repair it.
Placing our new bath sink vanity base upside down, we sealed the bottom edges as well as all other un-coated surfaces on the vanity back (and front kickboard) before the new unit was installed.
We continued mold-proofing this bathroom with the details listed just below.
We take these steps to reduce future mold growth in baths:
Install a high capacity low sone (quiet) bath vent fan, making sure that the fan is properly vented to outdoors and that fan duct condensation will drain outside and not into the ceiling space. See HUMIDITY CONTROL TO PREVENT MOLD
Install sliding glass tub doors in baths where users are careless with shower curtains (that also grow mold, especially cloth shower curtains) and for people who splash water onto the bath floor
Seal the un-coated hidden sides of new vanity cabinets, such as the vanity bottom edges, back and under-side before installing the new vanity. We use a spray shellac but any water resistant coating will do. Coating these surfaces reduces their moisture uptake and thus increases mold resistance.
Caulk the sink vanity to the floor to be sure that spilled water from a shower or tub does not run below the vanity as we explained at Photo Guide to Mold Under Vanity Cabinets. We used clear caulk at the exposed vanity edges where they contacted the floor, extending caulk up the vanity sides as well. Against a white drywall bathroom wall use white polyurethane caulk for better appearance and easy cleanup.
Caulk the floor trim at floor level - if installing new trim, run a small bead of caulk along the bottom edge of the trim boards before they are nailed in place - you won't see the caulk but you'll keep water out of the wall cavities when it spills onto the floor.
Clean the tile surfaces after showering - use a squeegee to clean water and soap scum off of tile walls and shower doors - they will look better and you'll be reducing the organic debris on those surfaces, thus reducing mold growth.
Do not leave very wet towels hung from hooks anywhere; spread them out on towel racks to dry, or put wet towels into the laundry. One of the moldiest closets we found in a home without other leaks was caused by an owner who daily hung his very wet towel on the back of the door to a tiny, clothes-filled closet, closing the door trapping moisture there.
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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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