Should You Put Visqueen Under Concrete

Recently, though, research has shown that the old traditional layer of 6-mil Visqueen (polyethylene plastic) under the slab is seldom effective for two main reasons: Although it may seem water-tight, this grade of material allows a lot of water vapor to pass through.

Should I use a vapor barrier under concrete?

The single most important reason you should use a high-performance vapor barrier is to protect the expensive floor covering in your building. … Water vapor diffusing through the concrete slab can also lead to deformation and discoloration of the floor covering material, leading to costly repairs or even replacement.

Do I need black plastic under my concrete slab?

Vapour barriers are the black (or orange) plastic that builders put under residential house slabs. They do this for two main reasons: to prevent moisture from the soil permeating up through a slab and into a house (also known as rising damp); and.