How to Frame Soffits for the House

Measure the width and length of the obstruction, as well as the distance between the bottom of the obstruction and the ceiling joists, with a measuring tape.

Measure four sections of 2-by-4-inch lumber to the length of the obstruction. Cut the sections to length with a circular saw.

Subtract 2 inches from the distance between the bottom of the obstruction and the bottom of the ceiling joists. Cut sections of 2-by-4-inch lumber to this measurement to form the side studs of the frame. Cut two sections for each end of the soffit and two sections for each 16 inches of soffit length.

Lay two length sections parallel on the floor on their 2-inch sides. Place a side stud between the length sections at each end, and at 16-inch intervals between the end studs. Repeat this process with the remaining length sections and side studs.

Drill pilot holes through the length sections into the ends of the studs -- the pilot holes should be slightly smaller than the diameter of the wood screw shafts. Insert and tighten 4-inch wood screws through the pilot holes with an electric screwdriver to secure the soffit sides.

Place one soffit side 1 inch from the side of the obstruction along the ceiling joists. Drill pilot holes through the top length section into the joists. Insert and tighten 4-inch wood screws through the pilot holes into the joists to secure the soffit side. Repeat this process with the remaining soffit side on the opposite side of the obstruction.

Measure the interior distance between the bottom length sections of the soffit sides. Cut sections of 2-by-4-inch lumber to this measurement with a circular saw to form the width sections. Cut one section for each end and for each 16 inches of length between the end width sections.

Place one width section between the bottom length sections at each end of the soffit, and at 16-inch intervals between the end width sections. Drill pilot holes through the bottom length sections into the ends of the width sections. Insert and tighten 6-inch wood screws through the pilot holes.