To paraphrase a popular song, mold is in the air. It is a living organism, requiring food and water and releasing thousands of tiny mold spores into the air to reproduce. All good and part of the natural order of life until those microscopic spores enter our homes and grow indoors.
Prevent mold growth by controlling moisture. No moisture, no mold growth. Fix plumbing, roof and other water leaks promptly. To avoid condensation problems, keep indoor relative humidity low, between 30-50%. A hygrometer, found at most home electronics stores, can measure your home’s relative humidity. Alternately, look for signs of condensation on windows.
The best approach for reducing indoor moisture is to exchange daily the moisture-rich indoor air with outside air. Even bringing our humid outdoor air indoors is helpful as the air will dry out when it is heated. If your home was built after 1991, it should have a whole-house ventilation system; use it to control humidity. Otherwise, opening windows to allow cross ventilation for a short time will accomplish the same.
While cooking, bathing or washing laundry, be sure to use exhaust fans vented to the outdoors. Run until the room is dry, at least 45 minutes after bathing.
To eliminate existing mold growth, first follow the two Fs—find and fix the moisture source. Since mold spores are continuously entering our homes, removing its source of water is most effective in the long run. If you skip this step but remove the mold stains with bleach, you will not see the mold, but it may still be present. If you skip this step and just use a deodorizer, you will not smell the mold, but it is still there.
To remove existing growth, clean hard surfaces with soap, water and a little elbow grease. Small areas of surface mold on walls or ceilings can easily be cleaned this way. For larger areas, take precautions to prevent breathing the spores and seal the work area so as to not release spores to the rest of the house. For areas greater than 3 feet by 3 feet consider calling a certified mold remediation contractor trained in best practices, including room containment.
Whether to clean or discard materials depends on the material. Hard surfaces can be cleaned and washable items can be laundered. Discard porous materials that cannot be washed, like wallboard, upholstered furniture or carpeting. For walls, the affected section plus a foot of material in all directions can be removed, depending upon the severity of the damage.
To remove mildew from clothing, wash normally, but dry in the sun. If any stain remains, apply a paste of lemon juice and salt, then spread in the sun. Do test a small area for color fastness first.
Consider this. If it smells musty, but you can’t see mold, you have mold growth. Look for it where you find water—baths and kitchens; areas with high humidity and cold walls, like laundry rooms or bedroom closets near attached baths. Mold growth can also be hidden—behind bathroom wallpaper; inside walls, especially under windows or near pipes; behind baseboards; behind big furniture or stored items where dry air can’t circulate; and under basement carpeting. A home inspection focused on water intrusion can be helpful in identifying problem areas.
Generally, testing for mold is unnecessary as the remediation process is the same for all types of mold, regardless of color or species. However, testing is useful if you suspect exposure even though no mold growth has been found, especially if a physician has identified mold-related health issues.
If you rent or are a landlord, take a look at resources listed in Renters, Landlords and Mold at the Washington State Department of Health.
For more information:
Washington State Department of Health, Mold Information recorded line: 360-236-3090
Northwest Clean Air Agency YouTube video, Mold in Your Home.
American Lung Association, Mold and Dampness.
EPA, A Brief Guide to Mold, Moisture, and Your Home.
Washington State, Department of Health, Mold.