How to fix a jammed window

If your window is jamming because it fits too tightly within the sash, it may just be the weather. Moisture swells wood which can affect how easy it is to open and close windows. You could just wait for the weather to change but if that window needs opening now, read our guide to find out the different ways you can fix a jammed window.

Level of difficulty

Level 2: Intermediate

What you need

• Dust sheets
• Chisel
• Thin piece of wood
• Silicone lubricant
• Damp cloth
• Sandpaper
• Screws
• Screwdriver

The steps to follow

Note:
Wet or damp weather may be the cause of a tight window. With an increase in humidity, wood can swell causing the window to tighten and jam. If the problem persists during winter, then you'll need to lubricate the window or strip the paint around the area that binds.

1. Cover your work area with a dust sheet.
2. Determine where the problem might be coming from.
3. If the problem lies in the binding spot, use a chisel to loosen and widen it. You can also use a thin piece of wood to wedge and loosen the problem spot.
4. Try opening the window to check if the problem is fixed.
5. If not, you can lubricate the window tracks with silicone lubricant. Clean the area in and around the window track with a damp cloth.
6. Apply a fair amount of silicone lubricant along the window tracks.
7. Open and close the window several times to evenly distribute the silicone lubricant over the window tracks.
8. You can also try to sand the edges of the window with coarse grade sandpaper to loosen it.
9. Unscrew and remove the window from the window frame.
10. Sand the paint off from the edges until you see bare wood. You can also strip the paint off from the edges.
11. Fit the window back into the window frame.
12. Tighten the screws and test the window.

Note:
A broken sash cord might also be one of the reasons for a jammed window. In this case, you'll need to replace it with a new sash cord.