Exterior Wall Vapor Barrier Installation

Using other kinds of tape will compromise the waterproof seal and render the barrier useless.

Exterior wall vapor barrier installation. 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. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.

When a vapor barrier is on the side of a wall where the dry air is i e outside in winter or inside in summer moisture problems can occur. It combines the superior air and water resistance vapor permeability and strength of tyvek with a vertically grooved surface to help channel water safely to the outside. How to install poly vapor barrier. Not every wall does.

The science of moisture movement. Thus installing vapor barriers on wall surfaces must. A vapor barrier s job is to keep water vapor in humid air from diffusing through one side of a wall and finding a cool surface inside the wall. To be extra certain use a caulk gun to place caulk material around the tape to double seal the barrier.

How did this project turn out. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Finish the wall within a month of installing the barrier to prevent damage to the surface and protect the vapor barrier. Dupont tyvek drainwrap is a moisture barrier designed to provide enhanced drainage in areas subject to extreme wind driven rain.

Tar paper has been time tested as a weather barrier. In exterior walls that are below grade like basement walls. This is generally referred to as installing vapour barrier because the main function is to stop the warm moist air in your home from entering the cold interior space inside of your wall cavity. Tar paper keeps the wood beneath it dry.

In any case the vapor barrier must point to the warm side. Installing polyethylene poly to the warm side of a exterior wall is very important. Whether or not you need a vapor retarder hinges on three main factors.