From 
Image 1 of 17
1.Install a temporary support wall 2 to 3 ft. from the exterior wall. Position studs directly under each truss or ceiling joist. Turn off power to any outlets or switches in the wall.
Image 2 of 17
2. Cut through finish nails securing the window using a reciprocating saw. Cut back the siding with a circular saw if necessary to expose the nailing fins that hold the window in place. Remove the window.
Image 3 of 17
3. Remove the drywall or plaster, then the framing that formed the old window opening. Use a reciprocating saw to cut through nails securing the exterior sheathing to the framing. Use a BIG sledgehammer to bash the studs and trimmers away from the header, then use a BIG pry bar—a 3-ft. one gives you lots of leverage—to pry the old header down and away from the top nailing plates.
Image 4 of 17
4. Install the new header. First mark the rough opening and position of the new studs and trimmers on the bottom nailing plate. Use a 4-ft. level to plumb and toenail the new king studs and one trimmer on each end. Lift the two 1-3/4 x 11-7/8 in. laminated headers into place, and nail them to each other, top, middle and bottom, every 12 in. with 16d nails. Add the two additional trimmers, then remove the temporary wall.
Tip
Your temporary support wall can do double-duty; staple plastic to it to help contain the debris and dust.
Image 5 of 17
5. Nail the new cripples to the bottom plate using 16d nails, then cut and nail the new sill in place. We “sistered” longer cripples alongside existing ones to create the correct opening height. If your new window is taller, you’ll need to cut the cripples shorter.
Image 6 of 17
6. & 7. Lift and position the new window into place. Use sawhorses, blocks and shims to temporarily support the window.
Tip
Remove the operable window sashes to lighten the weight, especially if you’re working off ladders.
Image 7 of 17
6. & 7. Lift and position the new window into place. Use sawhorses, blocks and shims to temporarily support the window.
Tip
Remove the operable window sashes to lighten the weight, especially if you’re working off ladders.
Image 8 of 17
8. Level the windowsill with shims every 16 in. Move the window in or out until the extension jamb is even with a scrap of material the same thickness as the finished wall. Use your 4-ft. level to make certain the sides are plumb and the window square, then install shims every 16 in. Drive 10d finish nails through all the shims to secure the window in the rough opening.
Image 9 of 17
9. Use cable clamps to tighten the support cables around eye hooks screwed firmly into the header. If space over the window is limited (our manufacturer wanted a minimum 30-degree cable angle), secure the cables to eye hooks screwed into the over-hanging rafter tails or blocking nailed between the tails.
Image 10 of 17
10. Tighten the adjustment nut on the bottom until the footboard is level or slants slightly upward (about 1/8 in.), to compensate for cable stretch. Do it right; once the bottom of the window is insulated and sheathed, the nuts will be inaccessible.
Image 11 of 17
11. Enclose the window bottom. Use big-head, plastic cap nails to secure 2-in. rigid insulation to the footboard, then secure the 3/4-in. plywood by driving 3-1/2 in. drywall screws through the insulation and into (but not through!) the footboard. Use 4d galvanized nails to secure the soffit plywood to the 3/4-in. plywood. Keep the edges of all three layers even with the edges of the window.
Image 12 of 17
12. Use a level to transfer the profile of the window up to the soffit, then make marks 1/2 in. back and secure 1x2 cleats to those marks. Add fiberglass insulation to the cavity. If the distance from window top to soffit is less than 6 in., you can enclose the top with the same metal flashing shown in Photo 15.
Image 13 of 17
13.Screw 1/2-in. plywood to the cleats. Since we enclosed one of the existing soffit vents, we added another one to the left of the bow window.
Tip:
Level the footboard, then raise it an extra 1/8 in. using the cable nuts. That way, when the cables stretch and the rafters or header they’re attached to “gives” a little (and that’s inevitable), the window will wind up level.
Image 14 of 17
14. Apply caulk to the back of the side flashing, then tap the tongue of the flashing into the groove of the window. Prevent damage to flashings by hammering against a wood scrap.
Image 15 of 17
15. Install the bottom flashing. First hold the flashing in place, mark the corners and lightly prebend the flashing to accommodate the profile of the window. Secure it into the bottom groove of the window using a tapping block. Caulk the seam between the bottom and side flashings.
Image 16 of 17
16. Install the exterior trim and siding. Above the window we nailed corner blocks over the seams and filled between them with lap siding. We cut cedar lengthwise for trim alongside the window. Rather than filling in the wide space on the left side with short pieces of siding, we removed the siding back to the corner of the house and installed full-length pieces.
Image 17 of 17
17. Cut the interior trim and nail it in place, using a nail set to sink nailheads below the surface of the wood. Apply one coat of finish, fill the nail holes with putty that matches the wood color, then apply a second coat of finish. Our trim and cabinets are Douglas fir, finished with a lightly tinted polyurethane.
Copyright ©2005 Home Service Publications, Inc.
Comments :