Timber decay and woodworm
The window board is soft and the sash above it is hard. Which timber is the decay note?
The window board is the timber in the decay note, not the sash above it. The board is soft and the sash is hard, so the survey has marked the shelf at the cill rather than the sliding sash. Softness there is decay in that piece. A hard sash means this note has not condemned the frame above. The survey has not lifted the board to see how far the softness goes, and it has not named a species of rot beyond the timber it could feel.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Window boards sit on the cill and take the drips and condensation the sash may shrug off. The board can be saturated while the sash stiles stay firm, which is why the note names the board. A soft board can hide a wet cill beneath, but the survey did not lift it, so the cill is the next look rather than a finding. Hard sash timber is what was recorded above. It is not a promise about the hidden pulley stiles inside the boxes.
Ask a joiner to lift the soft board and see the cill before anyone replaces only the visible shelf. Tell the solicitor the decay note is the window board, with the sash recorded as hard. Do not price a new sash on this sentence. The survey has not opened the floor beside the window and it has not mapped decay beyond the soft board. The timber in the note is the board.
What should you ask your surveyor?
- Is the soft timber the window board rather than the sash?
- Was the sash above that board hard?
- Has the board been left unlifted, so the cill underneath is unseen?
What are the typical next steps?
- Treat the window board as the decay note.
- Ask a joiner to lift it and inspect the cill beneath.
- Do not price a new sash because the board is soft.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If the paint film is unbroken, is the board sound?
No. The board is soft, which is the decay note, even if paint still covers it. Paint can bridge a soft surface. The sash above was hard, so the note is not the sash. The survey has not lifted the board, and an unbroken film does not tell you how far the softness goes or what the cill is doing.
Does a hard sash mean the whole window assembly is clear?
No. The sash being hard means the sash was not the soft timber. The window board was. Boxes, cords and the cill under the board were not cleared by that contrast. The survey has not condemned the sash and it has not cleared everything around it. The decay note remains the board.