Insulation Vapour Barrier Attic

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

Insulation vapour barrier attic.

Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Not be trapped inside. The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation. In any case the vapor barrier must point to the warm side.

A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. You can forego the plastic and use a vapor retarder kraft faced insulation or latex ceiling paint in all other climates except hot humid or hot dry climates. Some regions don t require a vapor barrier. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather.

Not every wall does. Even if it asks you to. Since some leakage of moisture into the insulation in inevitable murphy s law you want it to be able to freely escape from the insulation into the attic. Vapor barriers in attics should only be installed on one side of the insulation.

Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days. 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 barriers are sheets of plastic or other material placed on one side of insulation sheets. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.

Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. 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. Vapor barriers keep the air moisture in your house from condensing in the insulated cavities. Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall.

Never compress or fluff your insulation.