Controlling Moisture in Crawl Spaces

Excess moisture in crawl spaces can lead to serious problems, including mold, mildew, and wood rot. Controlling moisture levels in crawl spaces is essential for maintaining a healthy and safe home environment.

How to Test for Moisture

Before taking steps to control moisture in a crawl space, it’s essential to determine the severity of the problem. A simple moisture test can be conducted as follows:

  • Place a plastic bag containing several calcium chloride crystals on the floor of the crawl space for 24 hours.
  • If the crystals remain dry, the crawl space is considered “dry.”
  • If the crystals turn slightly damp, the crawl space is considered “slightly damp.”
  • If the crystals become wet, the crawl space is considered “wet.”

Controlling Moisture Levels

Once the moisture level has been determined, several methods can be used to control it:

Vapor Barriers

Vapor barriers are installed on the ground and walls of the crawl space to prevent moisture from entering the space. They can be made of plastic sheeting, metal foil, or other impermeable materials.

Dehumidifiers

Dehumidifiers remove moisture from the air in the crawl space. They are effective in areas with high humidity levels.

Ventilation

Adequate ventilation allows moisture to escape from the crawl space. Vents should be installed in the crawl space walls or floor to allow air circulation.

Grading

Grading the soil around the home can help prevent water from pooling near the foundation and seeping into the crawl space. The soil should be sloped away from the home to create positive drainage.

French Drains

French drains are trenches filled with gravel or perforated pipe that are installed around the perimeter of the home. They collect water and direct it away from the foundation.

Conclusion

Controlling moisture levels in crawl spaces is crucial for maintaining a healthy and safe home. By following the steps outlined above, homeowners can prevent moisture-related problems and ensure the longevity of their homes.