Attic Vapor Barrier

The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it.

Attic vapor barrier.

Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions. 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. The inner surface in colder climates and the outer surface in hot humid climates.

In existing spaces oil based paints or vapor barrier latex paints offer an effective moisture 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 the following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation. Attic vapor barrier detail for cold climates. Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic.

Even though we apply vapor barriers to exterior insulated walls in cold climates it s no longer recommended for ceilings floor of the attic.