A vapor barrier basically helps to prevent moisture from entering your home through the ceiling floor or the walls.
Attic insulation vapor barrier.
Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case.
The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.
Some regions don t require a vapor barrier.
With a vapor barrier you will be able to significantly reduce this movement of vapor and make your living space more comfortable.
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.
If you do there is a chance that moisture that has slipped by the first vapor barrier will become trapped by the second vapor barrier decreasing the value of 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.
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.
A plastic vapor barrier is best installed in a vented attic within climates with over 8 000 heating degree days.
Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.
This acts as a barrier to keep heated moist air from rising up into the attic during cold weather.
When adding additional insulation to an attic that is already insulated never use insulation with a vapor barrier.
The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation.
Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.