Attic Knee Wall Construction

The knee wall will be built on the floor of the attic and then tipped into place against the rafters.

Attic knee wall construction.

Install insulation without misalignments compressions gaps or voids in all knee wall cavities. But you do so at the expense of floor space. In most instances they are no taller than 3 feet but some builders may custom fit them according to the roof s shape and size. If you aren t sure whether or not your attic contains knee walls go and look around the edges.

When insulated and covered with drywall the walls improve the thermal envelope of an attic. Framing basics for attic knee walls along the sides of your loft or attic space. Scribe a line on your scrap piece along the angle formed by the rafter. You can see the image below for an example of a knee wall.

Secondly without an air barrier on the back of the knee wall and with the potential to sag as indicated above attic air goes around the insulation into the cavity on the vertical space as well. The higher the knee wall the greater the amount of useful wall space you create in your finished attic. Support and follow me. Knee walls are short usually wooden walls installed around the sides of an attic where the rafters meet the floor.

Install a top and bottom plate or blocking at the top and bottom of all knee wall cavities. Determine the angle of rafters by setting the scrap piece of 2x4 in a vertical position against the side of a rafter. What are knee walls. Install an air barrier on the exterior of attic knee wall insulation and to block open floor joist cavities under attic knee walls.

Knee walls are short wood framed walls that install between the ceiling joists and rafters in an attic.