Insulating Knee Walls Vapor Barrier

The number one most important step in insulating and air sealing a knee wall is having a continuous air barrier.

Insulating knee walls vapor barrier.

Whether your vapor barrier is a facing or a film it must be placed on the warm in winter side of the wall. Insulation air sealing. 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.

Wow there s a lot of new stuff there. I ll deal with double vapor barriers more fully in another post let s take a look at a diagram of a finished knee wall job from energy smart home performance. The science of moisture movement. In any case the vapor barrier must point to the warm side.

Not every wall does. Thus installing vapor barriers on wall surfaces must. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

So before we get into the details there are a few choices to make. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. Vapor barriers keep the air moisture in your house from condensing in the insulated cavities. Whether or not you need a vapor retarder hinges on three main factors.

The biggest heat loss problems with knee walls are those gigantic holes in the air barrier.