Do I Need A Vapor Barrier In Attic Insulation

To install an efficient vapor barrier you need the dimensions of the room.

Do i need a vapor barrier in attic insulation.

Not every wall does. 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. The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it. For example the recommended vapor barrier in a home or office in a humid southern climate built with brick varies.

Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. Take the measurements with you when purchasing materials. In any case the vapor barrier must point to the warm side. Whether or not you need a vapor retarder hinges on three main factors.

A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. 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. 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. Do not overlook attic access door.

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. 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. 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. I install my vapor barrier in the middle of the wall system between the two walls.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Do i need a vapor barrier. Measure the entire area and write down the results. 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.