How to Repair a Stuck, Broken, or Rotted Window

Stack of old windows

If you have a new house with thermal-pane windows, you probably won’t need to undertake any forms of window repair. However, if your house is older and you still have single-pane windows that require storm windows in the winter, you might run into problems. You can carry out some of these window repair jobs yourself with just a little time and minimal equipment.

1. Window Repair for a Stuck Sash

brick building with a white sash window

If you can’t open a sash window, the most common cause is that it’s been painted shut. To free it, run a wide-blade putty knife between the window and the frame. If necessary, use a hammer on the knife. Tap lightly to break the paint seal. Do this on both sides and try to open the window again. (Make sure first that you have unlocked the catch.)

If this doesn’t work, do the same to the seals at the top and bottom of the window frame and try again. In most instances you will solve the problem. However, if you can only barely open the window, put a small piece of scrap lumber on the inside sill. Then use a pry bar to ease the window up. Be careful not to use too much force. Once you have opened the window, clean and lubricate the tracks to avoid a recurrence of the problem.

If the window won't open because of warping in the wood, you’ll need a professional carpenter.

2. Window Repair for Broken Glass

If you have a broken window, you can carry out the window repair. Wearing protective gloves, remove the old glass and scrape out the putty on both sides of the window. You’ll also need to ensure you take out all the old metal tabs that help hold the glass in place.

Use linseed oil on the exposed wood. If the frame is metal, paint it with rust-resistant paint. Measure the opening and have a piece of double-strength glass cut between 1/16 and 1/8 inch smaller than the opening.

Roll some putty into a thin tube between your fingers. Starting from one corner on the inside of the window, put a line of putty around the entire frame. Push the glass into place. On the outside of the window, push the metal tabs (also known as glazier's points) into the wood. Space them about six inches apart.

Now roll out more putty and put it around the window opening on the outside of the glass. Use the putty knife to push it down. To complete the window repair, use the knife or a razor blade to ensure the putty on both sides is even.

3. Window Repair for Rotted Wood

rotting wood on a white window

If part of your window frame or window sill has rotted, you might not need to replace the entire thing. Instead, you can conduct a window repair. If most of the wood is still good, just chisel out the rotted area. Then soak the area with liquid epoxy consolidant. After five minutes soak again. Keep doing so until the wood is flooded with the epoxy.

Now mix some epoxy filler and put it in the hole with a putty knife. Make sure it fills completely. Once the filler dries, you can sand it down to the level of the rest of the wood. You should paint or seal the wood within three days.