How to Replace a Broken Window Sash
- 1). Cut through paint alongside the window, using a utility knife. Use a pry bar to pull away wooden stops holding the bottom, interior window sash in place. Lift the inside window sash from the window opening and removed knotted cords that fit into holes on the sides of the window frame. Pry the narrow, vertical pieces of wood separating the two windows, called the parting beads, away from the window. Pull the upper, outside window sash away from the window opening.
- 2). Slice through the paint seal around the outside of the upper, outside sash. Use a wood block and hammer to tap the sash until it's freed from the window frame. Pull away any cords attached to the window. Go to each side jamb and open the small access panel. Remove the screw holding the panel closed, using a screwdriver. Reach into the cavity of the access panel and remove weights. Remove sash cords connected to weights and pull them from the access panel. Check that the pulleys at the top of each side jamb are not clogged with dirt. Use a putty knife to scrape off dried paint.
- 3). Put a couple drops of light machine oil on the pulley axles. Install 1/4-inch nylon sash rope by tying the end of a piece of string to a nail and tying the other end to the new sash cord. Feed these ropes over pulleys and down into the cavities of the wall. Tie the rope ends to the weights and put the weights back into the wall cavities. Sand and clean the side jambs with 100-grit sandpaper wrapped around a wood block.
- 4). Apply wax to edges of each sash. Trim the sash cords to size, and use the old cords as a reference for length. Tie knots into the cords and nail them into mortises, or cavities, on the sides of the windows. Put the cover for the access panel back into place. Push the back sash into the window jambs and put the parting beads back into place.
- 5). Repeat steps 2, 3, and 4 for the lower sash cords. Reinstall interior window stops, attaching them with wood screws or finishing nails. The finishing nails must enter the jambs just enough to secure the window stops. Test each sash to see if it works smoothly.
