Attic Insulation Vapour Barrier

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.

Attic insulation vapour barrier.

This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. 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. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. In hot dry climates your attic can be vented though like in hot humid climates you should not install any vapor retarder or barrier.

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. A vapor barrier basically helps to prevent moisture from entering your home through the ceiling floor or the walls. However all attics vented or unvented and in all climates should have an air barrier such as an airtight drywall ceiling. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.

Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. In any case the vapor barrier must point to the warm side.