How to Build an Interior Wall in an Attic Space With a Sloped Ceiling

Lay out the wall in the attic. Position the wall centered on a ceiling joist if the joists are parallel with the new wall. Place painter's tape on the floor outlining the wall. Your wall should be the width of a 2-by-4-inch board.

Hold a plumb bob over the outline of the wall and mark the locations of the corners where the plumb bob string touches the ceiling joist. This will allow you to align the wall perfectly.

Measure from the corner of the floor outline to the point where the floor touches the ceiling. Cut a 2-by-4-inch board to length. Nail the board to the floor using the outline as a guide. Use a framing nail gun and nail two nails every 8 inches. When possible, nail into the floor joist. This board is called a plate.

Measure the sloped ceiling from the plumb bob marks to where the floor touches the ceiling. Cut two boards to fit. Nail the first board in place using the framing nail gun. Together your two top boards form the top plate. Nail two nails every 8 inches of board. Nail the second plate directly over the first plate. You may need to trim the second board near the floor for fit.

Measure your height from the top of the bottom plate to the underside of the top plate. Use an angle-finding tool to determine the top angle. Set the miter saw to this angle and cut the top of your board. Toenail two nails into the top plates and two nails into the bottom plate. Recess the nails into the wood. Measure for a second board right next to the first board. This will make the corner stronger. Cut and install the second stud. Nail the two studs together as well as toenailing them.

Measure from the center of your second stud 16 inches. Mark your bottom plate at this spot. Measure another 16 inches and mark. Continue to the end of the wall. Measure, cut and nail in each stud keeping the studs level and straight. Measure between the studs and cut small 16-inch blocks. Nail through the ends holding the blocks horizontal to help stabilize the wall.