Vapor Barrier For Blown In Insulation

This acts as a barrier to keep heated moist air from rising up into the attic during cold weather.

Vapor barrier for blown in insulation. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Vapor barriers keep the air moisture in your house from condensing in the insulated cavities. 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. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

Settlement vapor barriers condensation r values voids this document assists building buyers owners or inspectors who need to diagnose identify or improve building insulation for new construction or retrofit and energy savings projects. A common misconception is that all insulations require vapor barriers in all situations. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. Cima does not recommend the use of vapor barriers with cellulose insulation except in circumstances of exceptionally high moisture levels such as an indoor pool facility or very cold climates.

Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Not every wall does.