Wall Vapor Barrier

Cover exposed foundation walls with 1 1 2 in.

Wall vapor barrier.

Set your store to see local availability add to cart. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. Whether or not you need a vapor retarder hinges on three main factors. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

In this wall assembly the vapor barrier is also the drainage plane and air barrier. The science of moisture movement. Certainteed membrain 12 ft. Out of stock online.

A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. This not only insulates the walls but also keeps rising dampness in the concrete from getting into the crawlspace. Of rigid moisture proof insulation. The wall assembly does contain water sensitive cavity insulation except where spray foam is used and it is important that this assembly can dry inwards therefore vapor semi impermeable interior finishes such as vinyl wall coverings should be avoided.

In any case the vapor barrier must point to the warm side. Not every wall does. We used thermax brand available through lumberyards of polyethylene vapor barrier because it doesn t require an additional fire barrier. Water vapor can pass through building materials in several ways including direct transmission and by heat transfer but studies suggest that fully 98 percent of the moisture transfer through walls occurs through air gaps including cracks around electrical fixtures and outlets and gaps along baseboards.

This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses. Air barrier with smart vapor retarder model 42821017 190 43 190 43.