Should Attic Insulation Have A Vapor Barrier

Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case.

Should attic insulation have a vapor 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. Now with attic insulation heat is no longer lost from the living space such that moisture may remain trapped in the attic vapor barriers were therefore necessary to reduce moisture flow into the attic. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.

To stop the movement of vapor effectively through air leaks your vapor barrier should also have an air barrier such as an airtight. Many types of blanket attic insulation already have a vapor barrier incorporated into them and will be effective at reducing moisture problems if fitted correctly. In circumstances where conditions inside a home or office are much different than outdoor conditions water. Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home.

Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. 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. Batt insulation is typically made of fibreglass or mineral wool.

Attic vapor barrier detail for cold 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. Make sure that you read the instructions carefully so you know which side is the vapor barrier and how to install it. In any case the vapor barrier must point to the warm side. Within the material there is a lot of air that provides the r value and for this reason batt insulation should be loose fitting.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. Not every wall does.