Exterior Stud Wall Vapor Barrier

The standard installation of a plastic vapor barrier is between the studs and the drywall but there are some exceptions to this.

Exterior stud wall vapor barrier.

How to insulate house walls from the outside. The exterior face of the wall or floor cavity should remain permeable in order to allow dissipation of any moisture that does enter the wall cavity. Window door openings connect both walls with 1 2 underlayment plywood and are sealed to the vapor retarder air barrier. This is then followed by a 2x4 wall with studs offset from exterior wall another 3 1 2 fiberglass or rockwool then sheetrock.

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. 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. Moisture driven inwards out of the brick veneer will condense on the. Dedicated vapor barriers have no place in a basement wall.

This will give you two vapor barriers one before and one after the stud wall framing. In any case the vapor barrier must point to the warm side. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. A vapor barrier reduces the movement of water vapor by.

It may look easy to go buy some packs of rigid insulation panels down at the. Adding extra insulation to the exterior walls of an older home when renovating or remodeling is a great way of improving a home s walls thermal performance and reducing energy use while reducing heating bills carbon footprint and improving a building s comfort level. 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. The other option is to set the 2 4 wall framing in 4 from the masonry or concrete basement walls and use just the vapor barrier on the insulation facing toward the living space.

Very hot and humid climates may benefit from an exterior vapor barrier that keeps outside humidity from penetrating into walls. If you are not sure if you need insulation in your walls follow along with this flow chart. Your first job after the studs are in place is to fill those walls with insulation. Since this wall assembly has a vapor barrier that is also a drainage plane it is not necessary to back vent the brick veneer reservoir cladding as in figure 6 and figure 7.

Such a wall system can be built with multiple thermal breaks with the weakest areas having an. In exterior walls that are below grade like basement walls. If you put a polyethylene vapor barrier behind a drywall covered stud framed wall then the answer is that water that condenses on the poly will fall onto the wood sill plate growing mold and eventually rotting it out.