Garage Attic Insulation Vapor Barrier

If you are not sure if you need insulation in your walls follow along with this flow chart.

Garage attic insulation vapor barrier.

Your first job after the studs are in place is to fill those walls with insulation. If you need a vapor barrier and your insulation is unfaced you must cover it with a polyethylene film. You don t mention whether there is a bonus room or living space above the garage. The classic answer is that the vapor barrier goes on the warm in winter side of the assembly.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Not every wall does. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. In cold climates a vapor barrier is almost always needed. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. If your garage is 45 degrees and you have a bonus room heated to 72 degrees above the garage the vapor retarder faces the upstairs room.

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.