6 Ways to Keep your Crawl Space Dry

1. Keep outside water out

An open plumbing penetration is allowing water and debris to enter crawl space.

A few steps should be taken to prevent water from the outside of your home from having an easy opportunity to make it’s way into your crawl space. Extend your gutters (above or below ground) away from your foundation. Make sure that you have at least 5% grade falling away from your foundation so that water can easily flow away from your home. Seal below ground penetrations in your foundation wall that were created during the construction process. A thorough inspection by our Moisture Intrusion Technicians can reveal these penetrations.

2. Adequate vapor barrier

The floor of your crawl space should be 100% covered with a minimum 6 Mil plastic barrier. This barrier can be upgraded by installing a thicker plastic and/or taping the seams. A thicker plastic can add to efficiency and longevity of your vapor barrier.

3. Waterproof the outside of your home

You can prevent water from seeping through the foundation walls by waterproofing the exterior surface of your crawl space walls. This process should be performed by a professional as it involves excavating the earth beside the wall, cleaning the wall, applying a waterproof membrane, and possibly installing a drain beside the footer.

4. Install a french drain and sump pump

It is not always ideal to excavate and waterproof the exterior of the home. In this case the water can be controlled by installing an interior French drain that moves the water out of the crawl space. Depending on the terrain of your yard, a French drain may also need to be installed in conjunction with a sump pump. 

5. Install a dehumidifier

A sealed crawl space before and after.

A dehumidifier can keep the humidity level low and reduce the chances of mold, but keep in mind that you will also need to seal any possible openings that can allow humid air to enter. Otherwise you will be unsuccessfully attempting to dehumidify your neighborhood! A few common culprits are the crawl vents, lack of a tight seal on the crawl door, and small holes in the masonry wall around wires, cables, and plumbing lines.

6. Seal (encapsulate) the entire crawl space

The best case scenario for maintaining an ideal humidity level in your crawl space is to seal or encapsulate the crawl space. A crawl space that is sealed properly will not allow any outside humidity to enter the crawl, creating a clean and dry environment. A sealed crawl space improves your home’s indoor air quality, improves the efficiency of your HVAC system, as well as creates an ideal environment for storage.