To repair a wood window, there are two main tasks to consider: fixing problems with the window frame and sash, and replacing or repairing the window glass. Let’s focus on the first task in this article.

The window sash holds the glass, and there are fixed or operable types of sash. Both can have issues, but operable sashes may have additional problems with their mechanisms. Over time, operable windows may become difficult to open.

Wooden windows are more susceptible to weather damage than those made of metal or composites. Prolonged exposure to dampness can cause wood to rot, while exposure to sunlight can lead to cracking. Termites can also attack wood. Double-hung wood windows, which have a bottom section that can be raised and a top section that can be lowered, are particularly problematic when they fail.

To preserve wooden frames, repaint them every three to five years, depending on the weather conditions in your area. However, be careful not to let built-up paint seal them shut or let the paint lap over any moving parts. Annual maintenance, such as filling cracks with putty and caulking the edges, will also help protect the frames. Vinyl and aluminum windows also require basic care to keep them working smoothly. Scrub them with a natural bristle brush and detergent solution, and restore the luster of anodized aluminum frames by polishing them with fine steel wool and coating them with paste wax.

If a wood sill or sash has been seriously damaged by weather and has begun to rot, you can use epoxy wood filler, available at home centers, to repair the area. However, if large areas are affected, consult a carpenter about cutting out and replacing sections of the wood or the entire sash. Alternatively, contact a window replacement or repair contractor if you need assistance.

To repair the damaged area with epoxy wood filler, follow these steps:

  1. Use a chisel to remove most of the loose, rotted wood. Drill a few 1/4-inch holes into the damaged wood. Soak the entire rotted area with liquid epoxy “consolidant” to transform the area into a sturdy base for filler. Let the wood absorb it for about five minutes and then reapply until it ceases to accept the consolidant.
  2. Mix a batch of epoxy filler according to the label directions and begin to mold the repair. As the material cures, use an old putty knife or flat paint stirring stick dipped in solvent to pack and shape the repair.
  3. Sand, file, and/or rasp the area until smooth and flat.
  4. After sanding the repaired area with epoxy wood filler, there may still be dips and voids due to the filler’s lack of pliability. To fill any remaining holes and voids, apply the exterior-grade vinyl patching compound with a putty knife. Allow it to dry, then sand it smooth and repeat the process if necessary. Finally, prime and paint the area within three days.

One common problem with double-hung windows is that they become stuck in their tracks. This can be caused by high humidity that swells the wood, accumulated grime that blocks the tracks, or repeated painting that seals the surfaces together. Here’s how to address these issues:

If a sash is temporarily stuck due to high humidity, wait for the weather to change. If a sash moves reluctantly, clean the sash channels. If the channel squeezes against the window, widen the channel by inserting a wood block where it binds and tapping it with a hammer. If grime blocks the channel, use a sharp wood chisel to remove the blockage. Then, sand the channel with medium sandpaper wrapped around a wood block and lubricate the channel with a wax coating.

If you can’t move the window, use a utility knife to cut through the painted edges of the sash. Then, work a 3-inch-wide putty knife between the sash and frame and tap it with a mallet. From outside, wedge a prybar between the sill and sash, and work alternately at each corner so the sash moves up evenly. Protect the sill with a wood block.

If you have a double-hung window that has been painted shut, you can usually get it working again by cutting through the paint and sealing the sash around its perimeter. Here’s how:

Use a utility knife or a window saw (a serrated metal spatula available at paint and hardware stores for about $10) to cut through the paint all around the movable sash. Be careful not to leave any areas uncut and to avoid damaging the painted surfaces.

Ensure the window is unlocked and no nails or screws are securing the sash to the jamb. If there are, remove them. Then try to force the window open with abrupt force, using the heels of your hands. If that doesn’t work, use a wood block and a hammer or mallet to free the window, but be careful not to jar the window so hard that you break the glass. Once you get the window open, brush away any loose paint.

As a window repair professional, I can provide you with some additional advice on how to repair your windows:

Window Sash Is Too Loose:

  1. If you prefer a more permanent solution, remove the sash and reposition the pivot pins. This may require more work, but it will ensure a more secure fit.
  2. You can also replace the weatherstripping around the sash to help reduce any gaps causing the looseness.

Window Falls Shut:

  1. When replacing the sash cords, use the same size and type of cord as the original.
  2. Inspect the pulleys to ensure they are in good working order. If the pulleys are damaged, they should be replaced as well.
  3. While you have the sash out, it’s a good idea to inspect the frame’s condition and make any necessary repairs.

How to Protect a Window Sill:

  1. If you don’t want to use aluminum, you can also protect your window sill with a coat of polyurethane or a layer of exterior-grade paint.
  2. Regularly inspect your window sills for any signs of damage or wear, and make any necessary repairs promptly.

Remember, if you’re uncomfortable with DIY window repairs, leaving it to the professionals is always best. can provide high-quality window repair services backed by a satisfaction guarantee. Contact us today to schedule an appointment!