Causes

• Countless mold spores are constantly circulating through the air. When air circulation within a space is insufficient, the spores settle onto surfaces. If growing conditions are sufficient, the mildew quickly spreads. According to the EPA, mildew can grow in temperatures ranging from 40 to 100 degrees Fahrenheit. It also requires a moist, relatively dark area, as well as a source of nutrients. Mildew can draw nutrients from any organic material, as well as man-made materials covered in nutrient-rich dirt or grease.
  
  

Prevention/Solution

• To prevent mildew growth, keep your home clean to minimize dirt and grease on different surfaces. Keep air circulating with a fan or by opening the window. Increase drainage and ventilation to keep moisture from building up, especially in damp areas like the basement. Use a dehumidifier or air conditioner to cool the room and reduce humidity. According to the "University of Minnesota," chemicals like silica gel and calcium sulfate can also help control moisture levels and keep mildew at bay.
  
  

Location

• Homeowners are most likely to find mildew in areas that are damp, dark or poorly ventilated. Basements, crawl spaces, garages and other wet areas are frequent targets for mildew due to the high moisture levels. Homes with insufficient ventilation, or rooms without windows or ventilation grills, are also likely to develop mildew if certain other conditions are right. Mildew is most often found on organic materials within these rooms, including drywall, paper, cloth, leather or wood.
  
  

Cleanup

• If you do experience mildew growth, it's important to get rid of it quickly. Open the windows to bring fresh air into the space. This will not only allow the air to circulate, it can also help dry up excess moisture. Any wet or mildewed items should be thrown away, except for those hard surfaces that can be cleaned. Mildewed drywall, rugs, insulation and other soft objects are often not able to be cleaned and should therefore be thrown away.
  
  Before cleaning, protect yourself with a dust mask and rubber gloves. Wipe down all hard surfaces with a non-ammonia cleanser, then disinfect with a ten-percent bleach solution.
  
  

Warning

• Mildew can cause a number of problems in the home. It is often associated with a musty, unpleasant odor. When it grows on a surface, it can stain or discolor the finish, even after the mildew has been cleaned off. Mildew can also cause objects to rot or decay, which can compromise the structural integrity of building materials. Like all mold, many types of mildew can also contribute to allergies or illness, so they should be cleaned up as quickly as possible.