Timber decay and woodworm
A window board is soft and the joist ends nearby were not probed. Why must the board not stand in for those joists?
A soft window board must not stand in for those joists because it is a finish piece, not the floor structure. Softness shows decay where the board was touched. The joist ends nearby were not probed, so their condition is unknown. Moisture that reached the board may also have reached the joists, or it may have stopped at the window. The survey cannot tell which. It recorded the soft board and the lack of a probe. It has not decided the joists are rotten, and it has not decided they are sound.
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?
Joist ends are the parts of the floor timbers that bear near the wall, often close to a window but hidden in the floor zone. A window board is the internal shelf. Probing one does not probe the other. Using the board as a proxy would pretend an inspection of structure that the visit did not make. The two timbers can share a damp path and still need their own look. The report should keep them as neighbours, not as substitutes.
If the floor structure matters here, ask for the joist ends to be probed where access allows, or instruct a timber specialist. Tell your solicitor the window board was soft and the joists were not tested. Do not tell a lender the floor timbers have failed, or that they are clear, on the strength of the board. The survey's finding stops at the piece that was actually touched.
What should you ask your surveyor?
- Was the soft finding limited to the window board?
- Were the nearby joist ends left unprobed?
- Has the report refused to copy the board's condition onto the joists?
What are the typical next steps?
- Keep the soft window board separate from the joist ends.
- Do not tell a lender the floor timbers were diagnosed from the board.
- Arrange a probe of the joist ends if that structure must be known.
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
Could the same moisture still be relevant to the joists?
Yes. Moisture at a window can track toward joist ends, which is why the unprobed ends matter. Relevance is not a result. The survey did not probe them and did not map a damp path between the two. Note the possibility. Do not write the joists up as decayed because the board is soft.
Does a firm floor underfoot clear the joist ends?
No. Boards can feel firm while the ends built into the wall are soft, and those ends were not probed. Walking the room tests the boards you stand on. It does not test the bearings. The window board remains the only timber this note actually describes as soft.