A concrete vapor barrier is simply a sheet of polyethylene plastic visqueen placed directly on top of the sub grade before the concrete floor or slab is poured to help keep moisture from the soil from passing up through the concrete.
Concrete slab vapor barrier.
Aci 302 1 guide for concrete floor and slab construction states that the minimum thickness of an effective vapor barrier is 10 mils.
The term vapor barrier is often used interchangeably with the term vapor retarder to describe all membranes used to resist water vapor transmission.
Thinner plastic can t stand up to the abuse of construction.
A vapor barrier is an impermeable membrane primarily used to resist water vapor transmission from the soil to the concrete slab.
Vapor barriers have been associated with certain concrete slab on grade problems including curling and cracking.
Vapor barriers are used because while fresh concrete is poured wet it s not supposed to stay that way.
They do not degrade when used in this environment like typical polyethylene film comprised of high amounts of recycled material and can be used in the construction of.
Many moisture problems associated with interior concrete floors and slabs on grade can be minimized or eliminated by installing a vapor barrier under the concrete.
It needs to dry and then stay dryto avoid flooring problems.
But they have also proven to be beneficial in reducing failures of moisture sensitive flooring materials adhesives and coatings caused by excessive emission of moisture vapor from concrete slabs.