Vapor Barrier For Blown In Insulation In Attic
Whether using loose fill or batts put the vapor barrier closest to the warm side of your installation where hot moist air would get in facing the house s interior in cold climates beneath floor insulation and the attic s interior in hot climates on top of floor insulation.
Vapor barrier for blown in insulation in attic. The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it. Cima can supply you with data regarding vapor barriers and cellulose insulation for your location. Fluffy bits of spun glass that are noncombustible and can t decay. R value declines by as much as 50 percent at temps below 0 degrees f.
With our vapor barrier installation services there will be no issue of the crawl space of your home becoming a residence for pests bats and rodents. With the added insulation the attic stayed cold and so did the ventilating air from outside which was now unable to effectively remove attic moisture. Attic insulation new construction or retrofit work. This worked well until we added large quantities of attic insulation.
Insulation labs is a name to reckon with for efficient vapor barrier installation services. 70 to 75 per sq. A plastic vapor barrier is best installed in a vented attic within climates with over 8 000 heating degree days. The insulation keeps the sheathing warm enough to prevent condensation of the water vapor.
Do not add a vapor barrier on top of the insulation in your attic since the paper facing on the existing insulation is the vapor barrier. Not every wall does. Click to enlarge graphic doe suggestion of a vapor barrier in double wall construction may not be necessary when using cellulose insulation in warmer climates. Attic vapor barrier detail for cold climates the best approach for a vented attic in a cold climate is installing a layer of drywall with a good coat of latex paint the paint creates a semi permeable vapor barrier.
There might always be water vapor in the insulation but it cannot condense because the sheathing is warm. Hence the need to reduce moisture flow into the attic and the need for a vapor barrier. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Some regions don t require a vapor barrier.