Exterior Wall Vapor Barrier Thickness

Window door openings connect both walls with 1 2 underlayment plywood and are sealed to the vapor retarder air barrier.

Exterior wall vapor barrier thickness. Not every wall does. This is then followed by a 2x4 wall with studs offset from exterior wall another 3 1 2 fiberglass or rockwool then sheetrock. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. The science of moisture movement.

There are two basic types of vapor barriers used with exterior wall insulation. Such a wall system can be built with multiple thermal breaks with the weakest areas having an. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. 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.

The standard installation of a plastic vapor barrier is between the studs and the drywall but there are some exceptions to this. In many of those cases vapor barrier paint woks better than installing sheeting. Instead of pulling away the insulation sheets to slip in the barriers apply at least one thick coat maybe two to the insulation. In exterior walls that are below grade like basement walls.

The application can vary so read all instructions on your specific brand of paint. The most common is paper faced insulation.