How to Frame a Cantilevered Wall

Prepare for the installation of the cantilevered wall by cutting the floor joists per your blueprints, to project a designated number of feet past the first floor’s paired top plates. Mark the top plates with the locations of each joist on 16-inch centers with two pencil marks, 1½ inches apart, marked “joist” or “J.”

Hang the joists, typically 2-by-8 lumber, from the band joist opposite the cantilever, using joist hangers. Lay the joist, termed to be “running wild” as it is not yet affixed to an end joist, over the first floor’s doubled top plate so the free end juts into the air. Line up each joist so that it falls between the marks of its location on the top plate. Nail seismic ties to connect the joist and plate, nailing through each hole in both arms of the tie with galvanized joist nails.

Mark an end joist every 16 inches on center with the locations for the regular joists, with a carpenter’s pencil, measuring tape and speed square. Tack temporary 2-by-4 braces under the end joist to hold it in place. Line up the running-wild ends of the regular joists so that each joist falls between the pencil marks of its marked location. Press a joist hanger up against the junction of the regular joist where it meets the end joist. Nail a joist nail through each hole on all faces of the joist hanger.

Follow standard wall-framing techniques to complete the cantilevered wall. Nail a subfloor such as plywood or OSB to the tops of the regular joists. Measure, mark and cut 2-by-4s to serve as bottom plates, top plates and regular studs. Lay out the wall elements on the subfloor and nail each joint with 16d nails. Add additional king studs, jack studs and cripple studs, as well as sills and headers, around rough openings for doors and windows. Lift the wall in place with the help of an assistant and nail it to the subfloor. Tack on temporary 2-by-4 braces until the trusses crew can add these roof framing elements to permanently affix the cantilevered wall’s top plates.