Before picking up tools, you must determine if the wood is salvageable. A simple "screwdriver test" works best: press a screwdriver into the suspect area. If it sinks in easily or the wood crumbles, you have rot.
| Condition | Verdict | |-----------|---------| | Single rotten sill, rest solid | | | Bottom sash rail rotted, but frame fine | Replace just the sash | | Frame corner rotted through | Replace the window | | Foggy double-pane glass + rot | Replace | | 100-year-old quarter-sawn oak with minor rot | Repair (restore!) |
Before you start repairing the rotted wood, assess the extent of the damage. Check for:
Rotted window wood is intimidating, but it’s one of the most satisfying DIY repairs you can do. Take your time, use real epoxy (not cheap filler), and you’ll buy your windows another decade of life. And your wallet will thank you.
Apply two coats of oil-based or bonding primer to the repair (epoxy is not UV stable). Then paint the entire window component. Pay special attention to sealing end grain and all seams.
Window Rotted Wood Repair Verified Jun 2026
Before picking up tools, you must determine if the wood is salvageable. A simple "screwdriver test" works best: press a screwdriver into the suspect area. If it sinks in easily or the wood crumbles, you have rot.
| Condition | Verdict | |-----------|---------| | Single rotten sill, rest solid | | | Bottom sash rail rotted, but frame fine | Replace just the sash | | Frame corner rotted through | Replace the window | | Foggy double-pane glass + rot | Replace | | 100-year-old quarter-sawn oak with minor rot | Repair (restore!) | window rotted wood repair
Before you start repairing the rotted wood, assess the extent of the damage. Check for: Before picking up tools, you must determine if
Rotted window wood is intimidating, but it’s one of the most satisfying DIY repairs you can do. Take your time, use real epoxy (not cheap filler), and you’ll buy your windows another decade of life. And your wallet will thank you. | Condition | Verdict | |-----------|---------| | Single
Apply two coats of oil-based or bonding primer to the repair (epoxy is not UV stable). Then paint the entire window component. Pay special attention to sealing end grain and all seams.