Do I Need A Vapor Barrier In Attic Insulation

Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.

Do i need a vapor barrier in attic insulation.

I install my vapor barrier in the middle of the wall system between the two walls. 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. Take a note of the construction of the attic and figure out which type of barrier will be suitable. Measure the entire area and write down the results.

To be able to answer this question correctly for your home there are a few factors you need to consider before any major attic insulation project. Take the measurements with you when purchasing materials. For example the recommended vapor barrier in a home or office in a humid southern climate built with brick varies. Do not overlook attic access door.

In any case the vapor barrier must point to the warm side. Not every wall does. Such a location works both as a vapor barrier as well as an air barrier and eliminates the need for an external air barrier not a easy application on a multi storried building as well as any special electrical pans and their sealing. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.

Once thought to be essential throughout a home or office vapor barriers are now strongly recommended only for certain conditions and methods for creating a vapor barrier must be tailored to fit the climate region and type of wall construction. 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. If you are planning to have an attic insulation project for your home you may be wondering whether it is important to have a vapor barrier installed as well.

Do not add a vapor barrier on top of the insulation in your attic since the paper facing on the existing insulation is the vapor barrier. The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Do i need a vapor barrier.