Indoor mold tends to grow in damp, dark environments, such as basements or showers and bathtubs, says Robert Fisher, the medical director at a Wisconsin-based practice called Allergy Research & Care. Because basements are so often affected, people with mold allergies should keep this in mind when choosing where to live, White says. "Don't rent in the basement, and don't put a bedroom in the basement," she says. Also, think about putting tile down as basement flooring rather than carpet. "If there's going to be water leakage," White says, "then carpet gets wet and moldy, so you want a floor that will dry easily."
Mold growth should be cleaned thoroughly using water, detergent, and 5 percent bleach, if needed. If mold spreads over an area larger than 10 square feet, the help of an indoor environmental professional may be needed, the AAAAI says.