Exterior Wall Vapour Barrier

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.

Exterior wall vapour barrier. Holes in the vapor barrier that allow humid air through may allow a lot more water vapor into an assembly than the vapor barrier is stopping. In hot climates any moisture that condenses on the exterior side of the vapor barrier will be drained to the exterior since the vapor barrier is also a drainage plane. Whether or not you need a vapor retarder hinges on three main factors. Moisture barrier between the sole plate the concrete slab.

Sole plates or sill plates are the first pieces of framing lumber placed in home construction. A vapor barrier reduces the movement of water vapor by diffusion. Dupont tyvek drainwrap is a moisture barrier designed to provide enhanced drainage in areas subject to extreme wind driven rain. In exterior walls that are below grade like basement walls.

These plates must be made of pressure. 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. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. The standard installation of a plastic vapor barrier is between the studs and the drywall but there are some exceptions to this.

Not every wall does. Vapor barriers are applied to the interior walls in climates which are predominantly cold while they are best applied to exterior wells in predominantly hot climates. In any case the vapor barrier must point to the warm side. 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.

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. Thus installing vapor barriers on wall surfaces must. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. An introduction to vapour barriers and vapour retarders.

A vapour barrier sometimes referred to as vapour retarder is typically a plastic or foil sheet used for damp proofing to prevent interstitial condensation from forming in various building assemblies such as walls roofs foundations and floors. The science of moisture movement. What is a vapour barrier.