Attic Insulation Ceiling Vapor Barrier

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.

Attic insulation ceiling vapor barrier.

Before the introduction of attic insulation attics in cold climates were poorly insulated and plastic ceiling vapor barriers were omitted. 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. Now with attic insulation heat is no longer lost from the living space such that. Not every wall does.

A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Some regions don t require a vapor barrier. A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

The heat being lost from the house below warmed up the attic so that moisture was lost through the vents as vapor. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. On the other hand an air barrier a properly detailed air tight drywall ceiling for example in the absence of a vapor barrier can be effective since it stops the flow of vapor laden air.

If you live in a cold climate place the vapor barrier between the interior of your home and the insulation. 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. When adding additional insulation to an attic that is already insulated never use insulation with a vapor barrier. If you live in a hot humid climate place the vapor barrier toward the outside of the wall cavity.

Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. In any case the vapor barrier must point to the warm side.