In any case the vapor barrier must point to the warm side.
Vapor barrier roof insulation.
To know if you need a vapor retarder ask yourself a few basic questions.
Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.
Vapor barriers applied over the face of the insulation provide additional benefits in the fight against moisture.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
That reduction of air and moisture infiltration can then help improve roof longevity.
A roof design that includes an adhered roof membrane with multiple layers of insulation with board joints offset and staggered over a vapor retarder air barrier helps lower the risk that air and the moisture it carries will infiltrate the roof system.
Formaldehyde free 1 moisture retardant 1 mold resistant 1 no dust material 1 vapor retardant 6 price.
Vapor barrier insulation 7 brand.
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 usually composed of a thin film such as polyethylene vapor barriers are used to retard or prevent water vapor diffusion into a wall ceiling or floor during the cold winter.
Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating.