Causes

• Fungus can grow in the crawl space under a house because the area is dark, has poor air circulation and is damp. These factors combine to create an ideal environment for mildew to grow and spread.
  
  

Issues

• High levels of humidity in a crawl space that lead to fungus growth under the house can encourage increased levels inside your home. This puts your living space at an increased risk of mildew growth.
  
  

Prevention

• You can prevent fungus growth in your crawl space by providing better air circulation through the area. If the soil is wet in the crawl space, dry it with a fan and then cover it with a layer of plastic. This will provide a moisture barrier between the soil and your home.