Garage Attic Insulation Vapor Barrier

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.

In mixed climate areas the vapor barrier is optional depending on the total design of a building. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Vapour barrier is on the top of the rafter then insul then board if heating garage insul vapour then board need hatch for summer to let out hot air i m a insulator typar is a better product in a.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. In cold climates a vapor barrier is almost always needed. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. The facing on faced insulation acts as a vapor retarder.

You don t mention whether there is a bonus room or living space above the garage. If you need a vapor barrier and your insulation is unfaced you must cover it with a polyethylene film. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. If you are not sure if you need insulation in your walls follow along with this flow chart.

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.