Vapour Barrier Exterior Wall

Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.

Vapour barrier exterior wall.

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. 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. A vapor barrier against the concrete surface is generally recommended before wood framing or flooring materials are installed. 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.

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. Any condensation on a properly installed continuous plastic vapor barrier will. Finished basements often receive a vapor barrier layer between the concrete and the floor treatment to prevent damage from heavy rains or other moisture seepage. In any case the vapor barrier must point to the warm side.

Below grade walls and floor slabs transmit ground moisture through concrete walls or slabs. 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. A continuous plastic vapor barrier prevents condensation from forming on the internal surfaces of the exterior wall. Very hot and humid climates may benefit from an exterior vapor barrier that keeps outside humidity from penetrating into walls.

This wall assembly will dry from the vapor barrier inwards and will dry from the vapor barrier outwards. Frame wall with cavity insulation and brick or stone veneer. To know if you need a vapor retarder ask yourself a few basic questions.