Housekeeping: How To Prevent and Remove Mildew

Mildew is a problem that occurs persistently in many Mississippi homes. Millions of tiny spores hover in the air ready to settle in damp, dark places, where they flourish.

What is mildew?

It is a thin, white to blue-green growth caused by microscopic mold spores in the air.

Where does it grow?

Mildew grows in damp, warm, poorly aired, poorly lighted places, such as in cellars, basements, and closets; on shower curtains and shower stalls; and under houses.

What harm does it do?

Besides looking unsightly, mildew has an unpleasant, musty odor. If permitted to grow, mildew will discolor and rot surfaces such as fabrics, wood, leather, and paper.

How can mildew be prevented?

The easiest way to prevent mildew is to let the sun shine in! Here are other prevention recommendations:

Keep Things Clean

Keep closets, dresser drawers, basements, and other likely places for mildew as clean as possible. Soil on articles can supply enough food for mildew to start growing if moisture and temperature conditions are suitable. Greasy films, such as those that form on kitchen walls, also contain many nutrients for mildew organisms.

Clean household fabrics are less likely to mildew than soiled fabrics. Because most manmade fibers (acetate, acrylic, polyester, and nylon) are resistant to mildew, clean fabrics made of these fibers will not support mold growth. However, even soil on these fabrics can supply food to start mildew. Thorough cleaning of all soiled fabrics, regardless of the kind of fiber, may help prevent their mildewing.

Get Rid of Dampness

Remove the cause. Try to control the causes of dampness so that mold spores, which are usually present in the air, won't settle on articles. Condensation of warm, moist air on cool surfaces often causes dampness in basements. Excessive moisture may indicate that repairs are needed. Some basements are continually wet from water leaking through crevices in the wall. Make sure that outside drainage is adequate and that crawl spaces under houses are kept dry. If a clothes dryer is equipped with a vent, have it exhausted to the outside to prevent condensation of moisture.

Dry the air: air conditioners and dehumidifiers. Cool air holds less moisture than warm air. If properly installed, air-conditioning systems remove moisture from the air by taking up warm air, cooling it, and circulating the cool air back into the room. In houses that are not air conditioned, including the basement, mechanical dehumidifiers are useful.

Provide heat. If necessary, get rid of dampness by heating the house for a short time. Then open doors and windows to let out moisture-laden air or use an exhaust fan to force the air out. Burn an electric lamp to dry the air in closets and other small areas. The heat may be sufficient to prevent mildew if the space is not too large. Precaution: Be sure to place the light bulb at a sufficient distance from clothing to avoid the danger of fire.

Use chemicals that absorb moisture. Use silica gel, activated alumina, or calcium chloride to absorb moisture from the air. These products, under various trade names, are sold by department stores, drugstores, and building supply dealers.

Silica gel and activated alumina are not harmful to fabrics. Their porous granules remain dry feeling even when saturated; they hold half their weight of water. To use, hang cloth bags of the chemical in clothing closets. Place an open container of it in the closet on a shelf or on the floor. Keep closet doors closed to eliminate moisture from outside air. Scatter dry granules through layers of clothing and other articles that are to be stored in tightly closed chests or trunks.

Provide adequate ventilation. Renew air circulation with ventilation. These air movements are of great importance in removing excess moisture. When the air outside is drier than that inside, ventilation allows the dry air to enter, take up excess moisture, and be carried outside. Use electric fans when natural breezes are not sufficient.

Poorly ventilated closets get damp and musty during continued wet weather, and articles stored in them may mildew. Try to improve the ventilation by opening the closet doors to permit natural ventilation or by installing fans.

Get rid of musty odors. Musty odors, which indicate mold growth, are sometimes noticeable in places such as basements and shower stalls. Take special precautions to eliminate musty odors as soon as possible. If you do, you will prevent objectionable, damaging mold growth. Usually musty odors disappear if the area is heated and dry. If odors remain, additional treatments may be necessary.

In cellars with dirt floors, use chlorinated lime (commonly called chloride of lime or bleaching powder) to remove musty odors. Sprinkle this chemical over the floor, let it stay until all mustiness disappears, then sweep it up.

To rid cement floors and tiled walls and floors of mustiness, scrub with a diluted solution of sodium hypochlorite or chlorine bleach. Use ½ to 1 cup of chlorine bleach to 1 gallon of water. Rinse with clean water and wipe dry. Keep windows open until walls and floors are completely dry.

Use quaternary ammonium compounds (available from janitorial, dairy, and poultry suppliers) on floors and walls. They are usually available as 10-percent solutions. Use 1 ounce of solution to each gallon of water.

Other commercial products are available for cleaning and sanitizing bathroom walls and washable surfaces.

How can mildew be removed?

If there is mildew on clothing or household fabrics, brush off the mold outdoors so spores do not scatter inside the house. Throw away vacuum cleaner bags because they may contain moisture as well as mildew-producing fungi.

Washable items. Launder with detergent and chlorine bleach if safe for the item's fabric. Otherwise, soak the item in an oxygen bleach, then wash.

Nonwashable items. Take to a dry cleaner. Be sure to identify the stain for the dry cleaner's information.

Upholstered furniture and mattresses. Take the item outdoors and brush away surface mold with a broom. Then vacuum clean, using an upholstery attachment. Place the item in the sun and air it thoroughly to stop further mold growth.

If mildew remains, sponge the item with thick, dry soap or detergent suds and wipe with a clean, damp cloth. If mold is growing deep in the padding of an upholstered piece or in a mattress, nothing will eliminate the mold or odor except renovation by a trained upholsterer or replacement of the item.

Rugs and carpets. Sponge with thick, dry soap or detergent suds and wipe clean with a damp cloth, or use a carpet shampoo. It is important to turn the rug or carpet upside down if excess water is a problem, allowing the wicking process to move stains or color bleeding to the base of the carpet fibers rather than to their surface. Let the item dry in the sun.

Wall-to-wall carpet. A different problem exists when treating wall-to-wall carpet because of the size of the item to be cleaned. Usually the best recommendation is to have a rug cleaner pick up the carpet, transport it to the plant, clean it, and dry it, if possible.

Shrinkage may cause the carpet to need restretching. If the water did not appreciably damage the backing, use a power stretcher, which supplies sufficient force, to restretch the carpet.

If the carpet cannot be removed, rent a vacuum capable of removing water from carpet. These machines can be rented from rental agencies, hardware stores, and grocery stores. Use a hot-water extraction unit for water removal. Do not attempt to use a home vacuum unless it is specifically designed as a wet vacuum.

Vacuum the carpet until no more water can be removed. If water has seeped under the carpet and into the underlayment, it may be impossible to pull the water through the carpet. If so, a portion of the carpet will have to be raised by pulling the carpet off the installation strips at one of the corners. After lifting a corner of the carpet, if the underlayment is wet, the entire carpet and underlayment will have to be removed. Once the floor has dried, the dry underlayment and carpet can be reinstalled.

If the musty mildew odor is still present in the underlayment or padding, it is best to replace it with new underlayment. Do not reinstall the padding with the thought that the odor will disappear eventually. Once carpet is placed over mildew, the problem will only worsen because the moisture cannot escape.

Painted surfaces. Painted surfaces also may attract mildew. Mildew attacks dark-colored paints more readily than white paints because darker paints contain more oil. They are softer, allowing the probing roots of the mildew fungus an easier entry. Surfaces that have been treated with linseed oil instead of paint are prime candidates for mildew. Remove mild cases of mildew on painted surfaces with a stiff brush. If the mildew comes off easily and leaves no stain, repaint with a mildew- resistant paint to eliminate the problem. Caution: Don't use mildew-resistant paints on surfaces accessible to children, such as on playpens or on window sills.

Scrub severe cases of mildew thoroughly with a solution of chlorine bleach. Use ½ to 1 cup of bleach to each gallon of water. Rinse with clean water and wipe the surface as dry as possible. This method can be used for cement floors, wall tiles, and all types of floor tiles. The bleach not only kills the fungus, but it removes the dead particles as well. Work quickly and carefully on plastic and asphalt tile to avoid spotting their surfaces.

Wood surfaces can be treated first with a solution of 4 to 6 tablespoons of washing soda to a gallon of water. Scrub well and then rinse with clean water. If this process doesn't remove the mildew, use one of the following remedies:

• 4-6 tablespoons trisodium phosphate cleanser and 2 tablespoons household ammonia per gallon of water
• 4-6 tablespoons trisodium phosphate cleaner and 1 cup liquid chlorine bleach per gallon of water. Rinse and dry thoroughly before repainting.

Leather goods. Leather goods should be wiped with a cloth wrung out of diluted alcohol (1 cup denatured or rubbing alcohol to 1 cup water). Dry in a current of air. If mildew remains, wash with a thick suds of mild soap or detergent, saddle soap, or a soap containing a germicide or fungicide. Wipe with a damp cloth and dry in an airy place. Polish leather shoes and luggage with a good wax dressing.

Paper and books. Remove dry, loose mold on paper and books with a clean, soft cloth. If mildewed paper is still damp, dry it first in an airy place. Spread out fanwise the pages of books to air. If the books are very damp, sprinkle cornstarch or talcum powder between the pages to absorb the moisture, allowing several hours for drying. Then brush off.

Wallpaper. To dry wallpaper, heat the room for several hours or days to dry the plaster board as well as the paper. Dry slowly to prevent cracking. If the paper is washable, wipe it with a cloth wrung out of thick soapsuds, then rinse with clean water. Pat, do not rub, with a soft, dry cloth. If stains remain, use a solution of household bleach, then sponge the stains with a cloth wrung out of clean water. Remove small stains with a commercial ink eradicator.

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Publication 2175
Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in furtherance of Acts of Congress, May 8 and June 30, 1914. Ronald A. Brown, Director

Copyright by Mississippi State University. All rights reserved.

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