How to Frame a Basement Knee Wall

Look for a stud in the wall adjacent to where you want to build the knee wall. Since the wall will not tie into the ceiling, it must have a wall to anchor to as well as the floor. Use a stud finder or tap on the wall and listen for a solid sound in contrast with the hollow sound that indicates the absence of a stud. Alternatively, drive a finish nail into the wall.

Measure up the wall, starting at the floor, to the height you wish your knee wall to reach. Mark a large "X" or other signifying mark.

Align a carpenter's level with the stud and determine when it reads straight up and down. Run a chalk snap line or pencil down the length, from the "X" mark to the floor, to create a guide for the knee wall installation.

Measure from the wall out into the room, stopping at the length you desire for your knee wall. Mark another "X" to indicate the end of the future wall.

Line up a straightedge with the plumb line on the wall and the "X" on the floor. Run a line, either with chalk or a pencil, across the expanse to guide the wall installation.

Cut two 2-by-4-inch boards to the length of wall you desire. These boards form your bottom and top plates for the stud wall -- the name for the wooden skeleton of any wall, whether full or knee-high.

Lay the plates flat on your work surface with the edges aligned. Measure over, from the beginning edge, 16 inches. Using a square to create a straight line, mark across both plates at once to indicate the center of a stud. Continue across the plates, marking lines every 16 inches until you run out of board.

Count the stud marks you created. Add two additional studs for the beginning of the wall and two more for the very end; to ensure a solid base for wall coverings, every stud wall always begins and ends with a double stud even if it leaves less than 16 inches between them and the next stud.

Subtract 3 inches from the desired wall height. Cut the number of studs determined previously to this length; since each 2-by-4 board is actually 1 1/2-inches thick, the stud height plus the header and footer will measure the height you want your wall.

Lay the bottom plate on its edge with the stud marks facing you. Place a stud on its edge as well, aligning the end with a stud mark. Drive two nails through the plate into the end of the stud to secure them together. Continue, working across the plate, attaching every stud, including the double beginning studs and double end studs, flush with the plate ends.

Place the top plate against the opposite end of the studs. Ensure the ends are flush with the beginning and ending studs. Drive nails through the plate into the stud ends.

Set the wall in place, checking with a level to ensure the wall is plumb. Nail through the double beginning studs into the stud in the adjacent wall, using two nails every 6 inches. Attach similarly through the bottom plate into the floor, using masonry screws if the floor is concrete. Finish with insulation and wall covering as desired.