Whether converting a garage to added living space or a home office area, closing the garage door opening is a simple framing project offering increased interior wall space or an opportunity to add a new door or window to the wall. Preplanning and the proper materials will ensure a successful remodeling project. The procedure for closing in a 6-inch wall can be adapted to any exterior wall thickness needed.
Remove the existing garage door, track assemblies and associated hardware.
Remove the existing garage door jamb and trim from both sides and the top of the garage door opening to expose the wall framing and header.
Snap a straight line across the floor of the opening at the outside face of the existing wall framing, using a chalk line. Use a builder's level to ensure the line is plumb with the outside face of the garage door header beam.
Cut a length of 1½-by-5½-inch pressure-treated lumber to the inside dimension of the opening at the slab. This piece will be the bottom plate of the fill-in framing assembly.
Position the pressure-treated lumber piece cut in Step 4 on the floor of the opening with the outside edge on the line marked in Step 2. Piece(s) should fit snug and against both sides of the opening. This will be the bottom plate of the fill-in framing assembly.
Cut a 1½-by-5½-inch board to match the length of pressure-treated board cut in Step 4. This will be the top plate of the fill-in framing assembly.
Make a pencil mark at 15¼ inches from one end of the pressure-treated bottom plate. From this first mark, complete the stud layout at 16-inch centers over the remainder of the plate length. Use a hand square to match layout marks onto both top and bottom plates.
Stack both plates flat on the floor, one on top of the other, and positioned on the wall line marked in Step 3. Measure the distance between the bottom of the garage door header and the top of the plates. This will be the wall stud length.
Cut one 1½-by-5½-inch wall stud for each layout line marked in Step 7 plus two for the wall end studs. Cut each to the length determined in Step 8.
Place the top and bottom plates on the garage floor, on edge, parallel and spaced sufficiently apart to insert the wall studs cut in Step 9 between them.
Position a single wall stud, on edge, for each of the layout lines on the plates and a single wall stud at both ends of the wall.
Attach each stud to the pressure-treated bottom plate on the 16-inch layout lines with two 16d nails through the plate into each stud end. Attach all of the studs to the same side of each layout line. Repeat at other end of the studs to attach the top plate.
Stand the wall upright and slide into the garage door opening, keeping the top plate flush with the outside edge of the existing garage door header and the bottom plate aligned with the wall line marked on the floor in Step 3. Use a builder's level to make the wall plumb.
Secure the top plate by nailing two 16d nails through the top plate into the header at each stud space. Secure the bottom plate to the floor slab with a single concrete nail between the studs at a minimum of 32 inches apart. The wall is ready for installation of wall insulation and/or the interior and exterior materials to match existing finishes.