Protecting your family’s health and your investment in your home requires that every homeowner check regularly for signs of mold and water damage. Whether mold is growing where water from a leak in your roof collected in your attic or it is growing on building materials in the crawl space under your house, the effects can damage your home, lead to costly repairs, and, maybe most importantly, affect the health of your family. 
Consider, if you will, that the frame and the basic structure of your home is built of wood or wood products. Many types of fungus can grow on wet wood products. Whether these are wood decoy fungi, or other types of mold and mildew, there is potential danger is allowing them to grow. One could damage the structure of your home; the other could damage the health of your family. 
 
Mold and other types of fungus will grow when four conditions are present in the right combination. These are:
  • Dust
  • Oxygen
  • Moisture (70% humidity or higher)
  • Temperature (68 to 86 degrees Fahrenheit)  
Because dust can be present on any building material (from insulation to paper to wood to glass to metal), it is important to inspect your home regularly when the temperature is at a level that supports the growth of fungus. While mold and mildew will not damage wood, wood decoy fungi will cause damage. Mold and mildew are a threat to your family’s health. Mold and mildew can cause allergic reactions, asthma and other respiratory illnesses.
 
Preventing the growth of mold and other types of harmful fungus or controlling its growth is a matter of preventing the accumulation of moisture on building materials. The main things a homeowner can do are:
  1. Control humidity levels inside the home
  2. Ensure that exterior materials provide proper seals against moisture
  3. Immediately repair any damage to the roof, exterior walls or basement and crawl space.
  4. If there is a leak, it is important to also dry out the materials thoroughly and immediately.  
Here are the main steps you can take to protect your home against mold and water damage and save money by preventing a need for costly repairs.
  • Check drainage around the foundation of your home. Make sure water is draining away from the sides of the house and not pooling near the foundation.
  • Check all downspouts to be sure they are carrying water away from the foundation
  • Check your crawl space to be sure there is adequate ventilation and that a moisture barrier has been properly installed.
  • Ensure that your dryer vent, kitchen exhaust ventilation system and bathroom vents are working properly, are adequate for the size of the rooms, and are venting to the outside of the house.
  • Check for dampness in your basement. If you detect dampness, run a dehumidifier and empty it often
  • Check for proper flashing and seals around the exterior access points (doors, windows, vents, etc.)
  • Check around windows, doors and other wall openings on a regular schedule to be certain that no moisture is seeping into your walls. Tight, waterproof seals are necessary around all openings through your walls.
  • Check regularly for dampness and condensation in the attic. Add or adjust vents if necessary
  • Make sure ventilation and dryer vents are not opening into the attic
  • Make sure all flashing is tight around places where the roof and the walls connect
  • Make sure moisture prevention materials required by local building codes have been properly installed in your attic http://www.saveonmyremodel.com/articles/article.cfm/save_money_by_protecting_your_home_against_mold_and_water_damage