Repair and Replace

• Dirt crawl spaces will always have humidity that creates a foundation for wood rot. Before outfitting the crawl space with a vapor barrier and dehumidifier, take the time to repair water-related issues. Inspect the roof of the house for leaks. Fix all downspouts and gutters. Look for plumbing leaks in the house in the bathrooms, the kitchen and the laundry areas. Check that water drains away from the foundation. You may need to grade the property to allow water to drain away from the crawl space. Remove and replace any damaged wood in the crawl space.
  
  

Encapsulate

• Install a vapor barrier in the crawl space. The vapor barrier will lower your utility costs and reduce mold and insect infestation. The floors in the house will be warmer in the winter. Check local building codes before installing a vapor barrier. Use at minimum a 6-mil plastic. Overlap the seams and use construction tape to seal the seams. The plastic should run 6 inches up the walls and be taped. Moisture proof and insulate the walls with a fire-resistant barrier. Insulate the joists. Place a termite barrier on the inside of the foundation.
  
  

Dehumidfiy

• Install a dehumidifier that is meant for crawl-space use. This type of dehumidifier does not have a bucket that requires emptying and will only run when necessary. Place the humidifier in the middle of the crawl space on a solid surface that is higher than the crawl space to allow for gravity drainage. The dehumidifier will reduce moisture and eliminate mold, dust mites and wood rot. The dehumidifier will need to be plugged into a standard three-prong outlet that is GFCI protected and out of the water. The dehumidifier can drain through a sump pump, an existing HVAC drainage system or a garden hose.
  
  Crawl-space dehumidifiers are sized based on cubic feet in the crawl space and how much moisture needs to be handled on a daily a basis. Additionally, the dehumidifier must be able to fit in the crawl space. Larger crawl spaces might need more than one dehumidifier installed.
  
  Once the repairs are completed, the vapor barrier installed and the dehumidifier is working, close or seal the vents in the crawl space.