Building Walls In An Attic

At the bottom points of the triangles the rafters meet the top plates of the exterior walls.

Building walls in an attic.

Consult your local building code and inquire about any necessary permits before beginning any such project. Footnote 12 building envelope assemblies including exterior walls and unvented attic assemblies where used shall comply with the relevant vapor retarder provisions of the 2015 international residential code irc. To build your walls to the correct length measure the angle of the rafter by laying a piece of 2x4 inch lumber against the side of the rafter in a vertical position. But they are awfully good to have.

Framing basics for attic knee walls along the sides of your loft or attic space. Use r 30 insulation for the ceiling and r 13 for the walls. If your attic space is framed with rafters and is unfinished it has a triangular shape. Mark the line that the angle forms along.

Staple insulation between the wall studs and ceiling joists image a. Don t mash or compress the insulation into the space. Knee walls are short wood framed walls that install between the ceiling joists and rafters in an attic. When insulated and covered with drywall the walls improve the thermal envelope of an attic.

Knee walls are not found in all attics and they are not absolutely necessary. Footnote 23 envelope leakage shall be determined by an approved verifier using a resnet approved testing protocol. It needs a certain amount of loft to work properly.