Insulation Vapour Barrier Attic

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

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. Even if it asks you to. Vapor barriers keep the air moisture in your house from condensing in the insulated cavities. 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.

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. Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days. 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. The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation.

Never compress or fluff your insulation. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. Not be trapped inside.

If you live in a cold climate place the vapor barrier between the interior of your home and the insulation. 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. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. 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 are sheets of plastic or other material placed on one side of insulation sheets. Vapor barriers in attics should only be installed on one side of the insulation.

Most forms of attic insulation benefit from the addition of a vapor barrier to protect them from the harmful effects of moisture which can reduce their effectiveness over time.