Attic Insulation Advice With Knee Walls

The blue lines representing insulation and hardboard on the graphic did not exist in my attic.

Attic insulation advice with knee walls.

Rake walls it s easier to handle than plywood or thermo ply and still gives you an r 19 r121 assembly depending on the original batt insulation installed. If you plan to insulate a kneewall and the attic floor behind the kneewall. Rather than leaving this space empty homeowners can fill it with insulation for additional thermal protection. Air seal and insulate the kneewall.

Then cover that same area with an r 8 fsk affixing it using cap nails. Once you ve decided which type is best for you examine the material options and prices to home in on the right product. In tight attics or odd shaped wall conditions i e. There are two basic ways to insulate a finished attic.

Two ways to insulate attic kneewalls good. The exact height of the knee wall is your choice. It is very easy to see where the studs are on this knee wall. Not so on these knee walls.

At the bottom points of the triangles the rafters meet the top plates of the exterior walls. As shown in the graphic above the knee wall lets in air from your eaves into the attic space. For diy attic insulation you ve got two choices. If you go back and view the illustration above you ll notice there s an enclosed area behind the knee wall.

But they are awfully good to have. Another alternative for knee walls conditions is to remove and reinstall the batt insulation to qii standards. It s usually easier and more effective to insulate the sloped ceiling rather than. As a comparison we can just barley see the horizontal ceiling joists.

Knee walls also provide pockets for additional insulation in the attic. If only the living space will be insulated wrap the insulation around the room s walls and ceiling and then continue along the floor of the non living space. Filling the space behind the knee walls with insulation helps to lock in your home s thermal energy. In this case the knee wall area becomes a cold space like traditional attic areas.

When the insulation is blown in on the attic floor all of the joists are covered and well insulated. Proper air blocks air barriers for example covering the insulation on the attic side and between the attic floor joists below the knee wall should be present. Both can be added to uninsulated attics or layered over existing material. In this case the area behind the knee wall will be uncomfortably hot or cold.

Insulate the sloped ceiling. Knee walls are not found in all attics and they are not absolutely necessary. If your attic space is framed with rafters and is unfinished it has a triangular shape.