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Mold and mildew control in your home


Many of us have seen mold and mildew around our homes from time to time. The problem can be particularly noticeable during the spring and summer months. Molds that generate mildew thrive wherever it is damp, warm, poorly lighted, and/or where air is not circulated. Molds produce tiny spores to reproduce. These spores float through the indoor and outdoor air continually. When mold spores land on a damp spot indoors they may begin growing and digesting whatever they are growing on in order to survive.


“You may find mold growth on wood, paper, carpet, foods and many other surfaces,” says University of Missouri Housing and Environmental Design Specialist Marsha Alexander.


When excessive moisture or water accumulates indoors, mold growth will often develop. This is especially true if the moisture problem remains unnoticed or unaddressed. There is no practical way to eliminate all molds and mold spores inside the house. The best way to control indoor mold growth is to control moisture and provide adequate ventilation. If you notice a moisture problem in your home, take steps immediately to find and fix the source of the water problem or leak to prevent mold growth. According to the Environmental Protection Agency, in most cases, mold will not grow if wet or damp items are dried within 24-48 hours.


If you find mold and mildew on building materials and furnishings, clean and dry the affected area immediately. Wash mold off hard surfaces with detergent and water. You may also choose to use a small amount of chlorine bleach and water on surfaces that will not be damaged and then dry completely. Chlorine bleach used in large quantities can be problematic so use sparingly. Absorbent materials (such as ceiling tiles and carpet) that become moldy may have to be replaced.


To prevent mold and mildew inside your home, reduce indoor humidity. If you don’t have a relative humidity gauge, purchase one so that you can monitor the indoor level. It is recommended to keep indoor relative humidity in the range of 35% to 55%. Vent bathrooms, dryers, and other moisture-generating sources to the outside. Use exhaust fans whenever you are cooking. Air conditioners will help to control indoor moisture. Utilizing de-humidifiers can also be very effective in controlling moisture. Check the ventilation system in your home and particularly in the attic area to make sure vents are not covered. In areas where there is a perpetual moisture problem such as a basement, do not install carpeting.


For more information on preventing mold and mildew contact your local University of Missouri Extension Center or visit the web site at


Source: Marsha Alexander, Housing and Environmental Design Specialist, University of Missouri Extension,



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Last update: Monday, April 26, 2010