How to Finish a Basement by Boxing in Beams

Measure the width and length of the beam you want to cover with a measuring tape.

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

Add 2 inches to the width of the beam, and cut sections of 2-by-4-inch lumber to this measurement with a circular saw to form the cross beams. You need one section for each 16 inches of beam length.

Lay out two of the length sections far enough apart to accommodate the cross beams. Place one cross beam between the length beams at each end and at 16-inch intervals between the ends to form the bottom section of the soffit. Insert 4-inch wood screws through the length beams into the ends of the cross beams with a drill equipped with a screwdriver bit.

Measure the height of the beam. Cut sections of 2-by-4-inch lumber to this measurement with a circular saw to form the height studs. You need two sections for each 16 inches of beam length.

Lay out one of the remaining length sections. Place the cut end of one height stud at each end of the length section, and place additional height stud at 16-inch intervals to form one side of the soffit. Insert a 4-inch wood screw through the length section into the end of each height stud. Repeat this process with the remaining height studs and length section to create the other side of the soffit.

Place one height section of the soffit 1 inch from the beam against the ceiling joists. Insert 4-inch wood screws to secure the side section to the floor joists. Repeat this process on the opposite side of the beam with the other height section.

Position the bottom of the soffit under the height studs. Insert 4-inch wood screws through the bottom soffit section into the bottoms of the height studs to complete the soffit frame.

Measure and cut sections of drywall with a utility knife to cover the sides and bottom of the soffit. Install the drywall by securing these sections to the frame with 2-inch drywall screws.

Cover the seams and corners of the drywall with drywall tape. Cover the screw heads and taped joints with drywall compound using a large putty knife. Sand the drywall with a palm sander to smooth out the joints after the compound has dried.