What thickness vapor barrier do I need?

6-mil for basic vented crawl spaces, 12-mil reinforced where there's foot traffic, and 20-mil for full encapsulation.

How much vapor barrier do I need?

Measure the crawl space floor plus the height you'll run up the walls, and add about 10% for overlaps.

Vapor Barrier

Stop ground moisture at the source. Shop polyethylene crawl space vapor barriers in 6-mil, 12-mil string-reinforced and 20-mil, each in 20 x 100 ft rolls covering 2,000 sq ft, or have our licensed crew install one under your home.

Showing all 3 results

Choosing a Thickness

6-mil: basic ground cover for vented crawl spaces that are rarely entered.
12-mil reinforced: resists tears from foot traffic; our most popular choice.
20-mil: heavy-duty liner for full encapsulation.

Installation Basics

Clear debris, rake the soil smooth, overlap seams 6 to 12 inches and tape them, and run the liner up the walls and around piers. Fix leaks and drainage first.

Vapor Barrier, Encapsulation and Dehumidifiers

A ground cover is step one. For persistent moisture, go further with encapsulation and a crawl space dehumidifier. See our vapor barrier installation service.

Vapor Barrier FAQ

What thickness vapor barrier do I need?: 6-mil for basic vented crawl spaces, 12-mil reinforced where there's foot traffic, and 20-mil for full encapsulation.
How much vapor barrier do I need?: Measure the crawl space floor plus the height you'll run up the walls, and add about 10% for overlaps.