Top 5 Tips for Sealing a Crawl Space

Posted by richard in Crawl Space Repair | 0 comments

From the Web site of Southface, a non-profit organization with the mission of saving energy, conserving water, and preserving the environment, comes a Top Ten List for Sealed Crawlspace Success.

The list discusses many of the issues that we here at Basement Systems have been addressing for the last 7 years, including the sealing of a crawl space with a thick, impermeable liner (you can’t save the planet if your throwing away a crawlspace full of 6-mil plastic every two years) and then conditioning the space.

You can see the crawl space list in it’s entirety at the Southface Web site, but as it deals with new construction, I have truncated it here to reflect sealing a crawl space in an existing home.

Here’s the list:

1. Moisture can enter the crawlspace when the home is being constructed, creating mold even before the home is completed. Proper drainage, sealing and insulating are important early in construction—before the floor joists are installed.
2. After construction, proper drainage is essential. Install a drainage plane on the foundation and a perimeter French drain that channels water away from the house.
3. Install continuous insulation on the walls. An example is a foam board that will not deteriorate should it ever get wet
4. Install a continuous, sealed plastic vapor barrier on the ground. Experience has shown that standard “6-mil poly” isn’t strong enough to survive construction so consider thicker, reinforced plastic. Overlap the seams and use mastic to seal the plastic “liner” to the walls and piers.
5. Construct a weatherstripped, properly insulated access door or crawlspace hatch.
6. Consider installing a dehumidifier plumbed to the outside or to a sump pump. Install a relative humidity (RH) meter and monitor it to keep the space below 50 percent relative humidity.

The CleanSpace Crawl Space Encapsulation System that addresses the above five issues. There are many products that make up the system, including a 20-mil crawl space vapor barrier with an anti-microbial agent built in.