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.

The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation. If you live in a cold climate place the vapor barrier between the interior of your home and the insulation. Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. Some regions don t require a vapor barrier.

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 in attics should only be installed on one side of the insulation. 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. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather.

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. 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. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. Never compress or fluff your insulation.

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. Not every wall does. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.

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. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. Even if it asks you to. Not be trapped inside.

In any case the vapor barrier must point to the warm side.