Does Attic Insulation Need A 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.

Does attic insulation need a vapor barrier. You do not need a 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. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. Not every wall does.

Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. If your climate does not meet these conditions a vapor retarder like latex ceiling paint will work well for your house if you are in all other climates except the hot dry and hot humid. The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation.

A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Since you already have insulation if there was a moisture problem you probably would have noticed signs of it already. A plastic vapor barrier is best installed in a vented attic within climates with over 8 000 heating degree days. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.

Several layers of paint on the ceiling would qualify as a vapor barrier.