Adjusting a Spring Lift
Tube-type lifting devices house a spring-driven twist rod that helps lift the sash. To improve sash movement, you can adjust the spring devices. But before tampering with these, check to be sure the window has not been painted shut.
1. Unscrew the lift. Grip the tube before you remove the screw, holding it in place, or the spring will unwind in a hurry. If the window sails up too easily, hold the screw and let the spring turn a couple of revolutions.
2. Rotate the lift. If the window is hard to raise, tighten the spring by turning it clockwise. You may need to adjust the lifts on both sides.
Replacing a Spring Lift
1. Remove the stop. Using a utility knife, score the paint between the inside stop and the casing. Pry with a putty knife to remove the inside stop on one side of the sash. This should make enough room to remove the sash.
2. Pull out the sash. Remove the screw that secures the tube, let the spring unwind, and then pull out the sash.
3. Replace the lift rod. Remove and replace the twist rod/tube unit. Reinstall the sash and adjust the tube.
Replacing a Sash Cord
Each sash in an old double-hung window is connected to two weights that run through channels in each side of the window. A sash cord or chain is secured to the sash and runs through a pulley near the top of the jamb. Sometimes a window binds because the cord has come out of its groove in the side of the sash; if so, force it back into position. If a cord or chain has become detached from the sash, reattach it with a short screw. If the cord is broken, replace it. A cord will not last as long as a sash chain, which also looks better.
Tools: Putty knife, utility knife, screwdriver or drill, and hammer.
1. Pry out the stop. Usually you need to remove only one inside stop. Cut through the paint using a utility knife. Using a putty knife, pry carefully at several points to loosen the stop, and then remove the stop with a flat pry bar.
2. Lift out the sash. Lift the sash and swing it clear from the frame. One or both cords may still be connected. Take care that a cord does not come loose and suddenly fly upward.
3. Detach the cord. Hang on to the cord and pull it out of the sash; you may need to pry out a nail or unscrew a screw. NOTE: Be careful never to let go of the cord. Pull it out and slip a nail through the knot so that the cord cannot slip through the pulley.
4. Open the access cover. There will probably be an access cover at the base of the jamb; unscrew the fasteners that hold the cover in place. Gently pry it out to reveal the weights. If there is no access cover, you may have to pry off the jamb.
5. Feed in the sash cord. Untie or cut the cord off of each weight and pull the weight out. Cut new cords or chains longer than they need to be. Feeding new sash cords or chains over pulleys calls for patience. Replace the cords or chains on both sides.
6. Attach the weight. Once the new cord or chain is visible through the access hole, tie a knot in the other end so that it cannot slip through the pulley. Tie the cord or chain to the weight and tug to make sure the knot is secure. Slip the weight back in place.
7. Check the weight’s position. Weights should hang 3 inches above the channel bottoms when the lower sash is raised fully. Once you have determined the correct length, knot the other end of the cord or chain and fit it into the groove. Secure the cord or chain with a short screw—don’t drive the screw into the windowpane.
8. Remove the upper sash. To replace the cords on an upper sash, you have to remove the lower one, then one of the parting stops. Use the same techniques as for the lower sash.
9. Replace the stop. When you replace stops, partially drive in longer nails, or drive in nails at different points. Raise and lower the sash to check the stop positioning; it should be fairly tight, yet allow for smooth operation.
Rehabbing an Old Double-Hung window? An old window will probably never insulate as well as a newer window. The cavity that houses the weights cannot be filled with insulation, and the panes are single-glazed. So installing new windows may save money in the long run. However if you have the time and energy, you can plug most of the leaks and make the window a smooth operator. Remove the sashes and sand their edges smooth. Repair the glazing and paint the glazing so that it is sealed with the glass. Caulk around all the casing and apron edges, both inside and outside. If you install a friction sash channel, you can remove the pulleys and fill in the cavity with insulation. Adding combination storm/screen windows will add a great deal to the insulating ability of a window.