Knee Wall Storage Insulation

Although kneewalls can help turn attics into living space they often present insulation challenges most builders install fiberglass batts between the studs and some type of blown insulation between the floor joists.

Knee wall storage insulation.

Kneewalls short walls under sloped ceilings are common in story and a half homes and in bonus rooms above garages. Walls the junction of the top plate and top of exterior walls should be sealed. Screw two support braces to the attic floor right behind the knee wall. We prefer cellulose but we use fiberglass sometimes too.

Another alternative for knee walls conditions is to remove and reinstall the batt insulation to qii standards. We reduced the air leakage nearly 50 on this house in shaker heights without insulating the walls. Rake walls it s easier to handle than plywood or thermo ply and still gives you an r 19 r121 assembly. Build the supports out of 2x4s making sure they re flush with the sill of the cutout.

Rather than leaving this space empty homeowners can fill it with insulation for additional thermal protection. Exterior thermal envelope insulation for framed walls should be installed in. Step 9 insert dresser photo by. Then cover that same area with an r 8 fsk affixing it using cap nails.

Use a hammer to remove any knee wall studs from the opening. In tight attics or odd shaped wall conditions i e. The knee wall storage unit must be insulated similarly to the attic space or the room will suffer from infiltrating air leaks. Below are the components from the table that are applicable to sealing and insulating attic knee walls.

If the attic is not insulated insulate the attic rafter. While they can be an ideal storage spot knee walls can t do much without being properly insulated fiberglass is layered down on the floor of the knee wall but since fiberglass doesn t stop airflow it doesn t do anything to insulate the area. The sloped roof creates a small space that can hardly be use. Blown insulation in the knee wall and top attics.

If you go back and view the illustration above you ll notice there s an enclosed area behind the knee wall. Added bonus the floor of this knee wall leaked too so there is a line of foam just above the floor joist. Also be sure to remove any insulation. R402 4 1 1 n1102 4 1 1 air barrier and insulation installation table.

Step 8 install supports photo by geoffrey gross.