Attic Insulation Vapor Barrier Direction

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.

Attic insulation vapor barrier direction.

If you put it on the right side where the humidity is it s not much of a vapor retarder. The placement of the vapor barrier depends largely on the climate where your house is. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. 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.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Not every wall does. Not so asphalt saturated kraft paper. Joe says in the article plastic vapor barriers really are vapor barriers when things get wet.

The purpose of insulation facing the facing on kraft faced insulation is made of kraft paper with an asphalt coating that makes the paper impermeable to water vapor. Never compress or fluff your insulation. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. The wetter it gets the better it dries.

If the insulation is installed with the paper vapor barrier facing away from the heated part of the home moisture from humid inside air can condense and become trapped in the insulation during cold winter months. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Also on the graph is the permeance of polyethylene.

Not be trapped inside. In cold climates the opposite is true. The paper creates a vapor barrier that helps keep the water vapor in the warm moist heated indoor air from migrating outward into the wall or other structure.