Controlling moisture from the soil beneath a slab is critical for protecting flooring systems, improving indoor environmental quality and helping maintain long-term building performance.

An under-slab vapor barrier or retarder is a sheet membrane installed beneath the slab to reduce the movement of water vapor and soil gases into the building.

Selecting the correct vapor barrier requires understanding material performance, installation requirements, project conditions and applicable standards.

Whether it is evident on the surface, water exists, to some degree underneath a building. This water can migrate through the soil and potentially contact the bottom of a concrete slab. To prevent water vapor from reaching the concrete, you’ll need a high performance under-slab vapor barrier between the sub-base material and slab.

Protecting the concrete slab and building interior from moisture sources below starts from the ground up. Choosing the correct below slab water vapor protection is imperative to your finished floor and overall health and safety. Proper selection and installation of a high-quality under-slab moisture barrier will result in a successful finished flooring system and provide you with long-term security and comfort.