Crawl Space Vapor Barriers

It is fairly common to see vapor barriers installed below basement sub-floors and in crawl spaces to prevent the moisture vapor from entering the area. Vapor barriers can be installed by laying heavy plastic on the ground surface, overlapping the joints, or by sealing all the joints and penetrations with a tape or adhesive compound (most common). The vapor barrier is then mechanically attached and sealed to the foundation wall, taking care that the barrier does not seal any of the wood framing below the vapor barrier. All debris in the crawl space is removed and disposed of prior to laying any vapor barrier in the area.