Measure the opening for the window with a measuring tape. Take the inside dimensions, side to side and top to bottom. Cut two pieces of 1-by-4 lumber , one piece to fit flat inside the top of the opening and one for the bottom, using a circular saw. Apply a thick bead of silicone caulk to the underside of the boards and nail them in place with a hammer and 2-inch finish nails.
Cut two pieces of 1-by-4 to fit inside the top and bottom pieces you just installed, flat against the opening sides. Measure and cut each side separately for a snug fit. Apply a bead of silicone to the back of each board and nail them in place, one against the right side, one against the left.
Cut two pieces of brick molding to fit inside the bottom opening. Miter both ends at 45 degrees, one right and one left, using a miter saw. Cut the miters at the ends of the wide face, with the detail on the long edge and the miters running down into the outside corners. Do the same for the top and sides, for a total of eight, two tops, two bottoms and two each right and left.
Drill pilot holes every 8 inches through the brick mold through the narrow edge, using a 1/8-inch bit. Apply a bead of silicone to the back of one bottom piece and set it into the opening, detail side out, flush with the outside edge of the opening. Drive one 2 1/2-inch finish head wood screw through each pilot hole with a cordless drill. Countersink the heads just slightly.
Apply silicone and install two side pieces, using the same technique. Caulk the back of a top piece and fit it between the side pieces. Drive one screw through each pilot hole.
Apply a bead of 100 percent silicone to the inside face of the brick mold and set your glass against it. Apply a bead around the exposed edge of the glass and a second bead on the face of the glass 1/2 inch from the edge.
Install the remaining pieces of brick molding with the detail in, using a similar technique to that used on the outside pieces. Press the molding against the glass and caulk the back of each piece before attaching.
Caulk all of the joints in the moldings with painter's caulk. Use a color close to your paint color if the frame will be painted and clear if it will be stained. Caulk over the screw holes in the brick mold as well.
Things You Will Need
- Tape measure
- 1-by-4 lumber
- Circular saw
- Finish nails
- Brick mold
- Miter saw
- Finish head screws
- Silicone caulk
- Painter's caulk
- Buy your glass 1/8 inch narrower and 1/8 inch shorter than the inside measurements of your 1-by-4 frame.