Mildew is one of the most insidious problems a homeowner can face. Ignoring the problem only makes it worse, as entire mold colonies can bloom; mildew is mold in the early stages. Baseboards are particularly attractive environments for mildew growth, as moisture can get trapped between the wall and the baseboard, leading to colonies' blooming. A detergent solution can kill off mildew and halt its growth. If the problem returns, consider removing the baseboard and cleaning the back, as well as the wall, to kill off remaining spores.
Things You'll Need
Lay a drop cloth to protect your floors from getting wet during the cleaning and to prevent moisture in the floors from contributing to your mildew problem.
Mix a solution of laundry detergent and warm water in a bucket. Use a capful of detergent for every gallon of water.
Dip a scrub brush into the solution and vigorously clean the baseboard. Scrub any concentrated patches of mildew especially well.
Dry the baseboards thoroughly with clean rags.
Mix 1/8 cup of bleach in a spray bottle with 1 quart of water. Apply a light mist to the baseboard to kill off any remaining mold spores. Color-test the baseboard first in an inconspicuous area if you're concerned about fading the paint. Allow the baseboards to air-dry.
Do not paint over a mildew- or mold-covered wall. According to the Washington State Department of Health, doing so will allow the mold to continue growing and eventually crack the paint.
Exposure to mildew and mold can cause respiratory and other health problems, especially for people with underlying medical conditions. Wear protective clothing and a face mask when cleaning mildew and mold, and open the windows to increase ventilation.