Attic Insulation Vapor Retarder

Sounds like a good idea but the vast majority of moisture problems are caused by air leakage not diffusion even in places like maine.

Attic insulation vapor retarder.

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. 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. The older term vapor barrier is still used even though vapor diffusion retarder is more accurate. Air movement and diffusion.

Cima does not recommend the use of vapor barriers with cellulose insulation except in circumstances of exceptionally high moisture levels such as an indoor pool facility or very cold climates. Moisture moves by two transport mechanism. In any case the vapor barrier must point to the warm side. 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.

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. You can forego the plastic and use a vapor retarder kraft faced insulation or latex ceiling paint in all other climates except hot humid or hot dry climates. If installed in an attic a continuous vapor retarder is usually used to reduce air infiltration. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.

A vapor barrier or vapor diffusion retarder is a material that reduces the rate at which water vapor can move through a material. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. Insulation labs is a name to reckon with for efficient vapor barrier installation services. First the kraft paper is a vapor retarder meant to reduce the potential for moisture problems caused by diffusion.

To know if you need a vapor retarder ask yourself a few basic questions. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days.

That s because cellulose is the only insulation that actually manages moisture. Do the air sealing. Stop worrying so much about vapor retarders.