Temperature

• Keep the temperature of your home comfortable, but low. Mold and mildew need heat to survive. Most types of mold and mildew thrive in temperatures that are higher than 75 degrees F. By lowering the temperature of the house (or room), you can reduce the chances that mold and mildew spores will thrive.
  
  

Humidity

• Control the humidity. Just as mold and mildew thrive in a warm environment, they also thrive in a moist one. This is why mold and mildew is seen most commonly around windowsills, in basements and in bathrooms. Use a dehumidifier to lower the house's relative humidity, and the mold and mildew will not have the moisture that's necessary to spread.
  
  

Ventilation

• Ventilate the affected area. Proper ventilation ensures that the temperature and relative humidity are more controlled and that new, fresh air can remove or hinder the growth of the mold and mildew spores. The less ventilation there is, the more likely it is that mold and mildew spores will replicate in an area.
  
  

Clutter and Cleanliness

• Get rid of clutter and keep things clean. Mold and mildew make use of any organic material, so eliminating items that are of no use often helps enormously in preventing and removing a mold and mildew issue. Organic materials that attract mold and mildew growth include old newspapers and books, kitchen grease, vegetable and fruit peelings, and old flowers left in a vase.
  
  

Light

• Open the draperies and let in the sunlight. Mold and mildew like to grow in dark places, which is why mold and mildew problems are most common in places like basements and closets.
  
  

Chemicals

• Use chemical products designed to slow or prevent mold and mildew growth. Purchase specific products for bath and shower tile, one of the most problematic places for mold and mildew. Consider purchasing mildew-resistant paints. You can also scrub down most surfaces with chlorine bleach.