Attic Insulation Advice With Knee Walls
Knee walls also provide pockets for additional insulation in the attic.
Attic insulation advice with knee walls. Rather than leaving this space empty homeowners can fill it with insulation for additional thermal protection. If you plan to insulate a kneewall and the attic floor behind the kneewall. There are two basic ways to insulate a finished attic. For diy attic insulation you ve got two choices.
Once you ve decided which type is best for you examine the material options and prices to home in on the right product. The blue lines representing insulation and hardboard on the graphic did not exist in my attic. It s usually easier and more effective to insulate the sloped ceiling rather than. 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.
In this case the knee wall area becomes a cold space like traditional attic areas. Knee walls are not found in all attics and they are not absolutely necessary. When the insulation is blown in on the attic floor all of the joists are covered and well insulated. Both can be added to uninsulated attics or layered over existing material.
If you go back and view the illustration above you ll notice there s an enclosed area behind the knee wall. Two ways to insulate attic kneewalls good. As i researched the possibility of insulating the attic space in my knee wall i learned that it was a major contributor to wasted energy. 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.
In tight attics or odd shaped wall conditions i e. Not so on these knee walls. Then cover that same area with an r 8 fsk affixing it using cap nails. Another alternative for knee walls conditions is to remove and reinstall the batt insulation to qii standards.
As a comparison we can just barley see the horizontal ceiling joists. The exact height of the knee wall is your choice. 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. Loose fill or batt the common term for blanket insulation.
It is very easy to see where the studs are on this knee wall. As shown in the graphic above the knee wall lets in air from your eaves into the attic space. At the bottom points of the triangles the rafters meet the top plates of the exterior walls. As well the access door should be insulated and sealed appropriately.
But they are awfully good to have. If your attic space is framed with rafters and is unfinished it has a triangular shape. In this case the area behind the knee wall will be uncomfortably hot or cold.