Garage Attic Insulation 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.

Garage attic insulation vapor barrier.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. There is a school of that maintains that an unheated garage that is attached to the house may get some benefit from insulating the walls and ceilings of the garage since it theoretically offers an additional thermal buffer. Some regions don t require a vapor barrier. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.

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. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. 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. Not every wall does.

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. Vapor barriers keep the air moisture in your house from condensing in the insulated cavities. Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.

In any case the vapor barrier must point to the warm side. If you live in a cold climate place the vapor barrier between the interior of your home and the insulation. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Over time this trapped moisture can rot the wood framing in your attic or cause mold and mildew to appear.