Attic Insulation Vapor Retarder

First the kraft paper is a vapor retarder meant to reduce the potential for moisture problems caused by diffusion.

Attic insulation vapor retarder.

Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. Moisture moves by two transport mechanism. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.

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. If installed in an attic a continuous vapor retarder is usually used to reduce air infiltration. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. The older term vapor barrier is still used even though vapor diffusion retarder is more accurate.

That s because cellulose is the only insulation that actually manages moisture. If this is accomplished and a similar air infiltration retarder is installed in sidewalls mechanical ventilation such as a heat recovery ventilator should be installed to prevent trapping air pollutants and moisture within the house. Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating. Stop worrying so much about vapor retarders.

A vapor barrier or vapor diffusion retarder is a material that reduces the rate at which water vapor can move through a material. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. With our vapor barrier installation services there will be no issue of the crawl space of your home becoming a residence for pests bats and rodents. In any case the vapor barrier must point to the warm side.

Sounds like a good idea but the vast majority of moisture problems are caused by air leakage not diffusion even in places like maine. Air movement and diffusion. Attic vapor barrier detail for cold climates 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. Do the air sealing.

Insulation labs is a name to reckon with for efficient vapor barrier installation services. To know if you need a vapor retarder ask yourself a few basic questions. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.