under slab vapor barrier

Under Slab Vapor Barrier

It’s no secret that moisture can cause problems in your foundation and walls.  When you properly install a vapor barrier underneath the concrete slabs, you can prevent moisture build-up related issues such as mold and mildew, delamination in the overlay or sealer, joint failure, spalling, cracking and deterioration.  Vapor barriers should be installed in both commercial and residential foundations to help prevent expensive repairs due to moisture damage.



There is a variety of polyethylene sheeting referred to as a “vapor barrier” or a “vapor retarder”, but not all of them can be applied as an under slab vapor barrier.  Vapor retarders are manufactured to meet ASTM E1745 specifications.  (Standard specification for water vapor retarders used in contact with soil or granular fill under concrete slabs.)  There are three classifications A, B, C with A being the most resistant to tearing and punctures and C being the least resistant.

Americover’s Vapor Barriers is composed of virgin polyolefin resins and offered in 10mil, 15mil and 20mil.  This is a high performance material designed to stop moisture migration and control the gases or contaminates from infiltrating the concrete slab, flooring and walls.  This vapor barrier can be installed over tamped earth, sand or aggregate base.  Simply unroll and completely cover the area receiving the slab, overlap the seams by 6 inches and seal by heat welding or with sealing tape.  All exposed penetrations should also be sealed.

Click here to see Americover’s Vapor Barriers