Manage Crawlspace Moisture
Crawlspaces moisture must be managed. As we know, the typical moisture levels and temperatures, crawlspaces are a perfect habitat for mold and termites. As a result, since we can’t easily control temperature, our goal is to restrict crawlspace moisture levels. There are more accurate and expensive methods to regulate the moisture in a crawlspace. For example, Encapsulation of the crawlspace with the installation of a moisture activated dehumidifier can regulate moisture levels and bring the crawlspace into a semi-conditioned environment.
Basic Crawlspace Building Practices
Outside of encapsulation, there are basic building practices that should be followed to control the moisture in your crawlspace:
- Proper grading around your home. Grading should drop away from the foundation 6 inches in the first 10 feet. Proper grading is necessary to carry rainwater runoff away from the foundation.
- Gutters: Gutters and downspouts should be installed around the structure to capture roof rain runoff and direct it away from the home.
- Maintain the function of existing gutters. Gutters filled with debris will overflow dumping water all along the foundation walls. This water and resulting moisture levels enter the crawlspace.
- Installing a vapor barrier that covers the entire exposed dirt floor of the crawlspace. Vapor barriers prevent the evaporation of soil moisture into the crawlspace atmosphere.
Water Invasion of Crawlspace
As you can see, these pictures of the crawlspace are extreme. None the less, they demonstrate how improper grading, lack of gutters and downspouts and no vapor barrier can affect crawlspace moisture. Additionally, at this home, the grading was actually sloped toward the foundation instead of away. The absence of gutters and downspouts resulted in all roof runoff being dropped along the crawlspace foundation. Correspondingly, with the vapor barrier absent, the constant supply of moisture continued to pour out of the soil into the crawlspace atmosphere. To compound matters, at the time of inspection, it had been raining on and off for 7 days.