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Combat Mold and Mildew

Submitted by Lorene Bartos, UNL Extension Educator

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Warmer weather and moisture can contribute to mildew growth.

Mildew is the common name for various molds. Mildew grows when it has a source of oxygen, nutrients, moisture and warmth. A musty odor is often the first warning sign of developing mildew.

Mildew can grow on textiles, furnishings and walls. It tends to grow in dark, damp basements and creates a musty smell that can permeate a house. Mildew can damage and discolor textiles, such as carpets and upholstery.

The optimal temperature range for mold growth is 77 to 86 degrees Fahrenheit. Mildew requires between 70 and 93 percent relative humidity and is promoted by slightly acidic conditions. Light is not required for mold to grow.

Mildew will grow in bathrooms, if there is excess moisture. Running the exhaust fan, drying down the shower and bathtub areas after use will help control mildew and mold.

If you are having trouble in crawl spaces under the house, spread a layer of moisture-barrier material such as heavy roofing paper of polyethylene plastic film over the soil. If possible, do not enclose the crawl space — good ventilation is important. Ventilation inhibits mildew growth by replacing moist air with drier air.

Tips to prevent mildew:

Keep areas clean — soil on dirty articles can supply enough food for mildew to start growing when moisture and temperature are right.

Get rid of dampness — dampness in a basement, or any other structure is often caused by condensation of moisture from humid air onto cooler surfaces. Excessive moisture may indicate repairs or additional insulation are needed. Make sure outside drainage is adequate.

Control moisture — if circulation is not adequate, cooking, laundering and bathing may add two gallons or more of water per day to a house. Use an exhaust fan, whenever possible.

Dry the air — cool air holds less moisture than warm air. Properly installed air conditioning systems remove moisture from the air by taking up warm air, cooling it (which removes moisture and circulates the cool, dry air back into the room. Dehumidifiers are useful in rooms (especially basements) that are not air conditioned. When using air conditioners or dehumidifiers, keep windows and doors closed.

Circulate the air — when the air outside is drier than inside. Ventilation allows the dry outside air to enter, take up excess moisture, and then carried back outside. When natural breezes are not sufficient, you can use electric fans to circulate the air from the house.

Get rid of musty odors, as soon as possible, to prevent further mold growth. Usually musty odor disappear when the area is dried.

To clean mildew or mold from hard surfaces, first clean with a solution of dish detergent and water. Then clean with a solution of 3/4 to 1 cup of liquid chlorine bleach to a gallon of water.

Molds and mildews can cause health problems for those who are allergic to them. Check basements and other areas often during humid and wet weather. To reduce mildew remove the moisture source.