Vapor Barrier Attic Floor

Some regions don t require a vapor barrier.

Vapor barrier attic floor.

The previous owner has 1 foam insulation with a a plastic vapor barrier only on the rafters of the roof about4 from the slate roof but not on the walls of the attic. On the other hand an air barrier a properly detailed air tight drywall ceiling for example in the absence of a vapor barrier can be effective since it stops the flow of vapor laden air. Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home. Even though we apply vapor barriers to exterior insulated walls in cold climates it s no longer recommended for ceilings floor of the attic.

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. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer. To know if you need a vapor retarder ask yourself a few basic questions.

In any case the vapor barrier must point to the warm side. Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. Resolution of the vapor barrier debate. My question is should iuse a vapor barrier inthe attic floor.

A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective. In circumstances where conditions inside a home or office are much different than outdoor conditions water. If you live in a cold climate place the vapor barrier between the interior of your home and the insulation. 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.

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. Vapor barriers keep the air moisture in your house from condensing in the insulated cavities. Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic. Most forms of attic insulation benefit from the addition of a vapor barrier to protect them from the harmful effects of moisture which can reduce their effectiveness over time the following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation.