Timber decay and woodworm
The suspended-timber joists the surveyor could see are dry and the wall they enter is damp. What joist end inside the wall is still hidden?
The joist end built into that damp wall is still hidden. The suspended-timber joists the surveyor could see are dry, which describes the visible span, not the end buried in masonry that is itself damp. Decay and wet rot commonly start at that bearing, where timber meets wet wall and air cannot dry it. The survey has seen dry timber in the open and a damp wall at the entry. It has not opened the wall, has not seen the joist end, and has not cleared it because the middle of the joist felt dry.
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?
A joist can be crisp in the room and soft in the pocket. The end is the piece built into or bearing on the wall, often the last few inches you cannot see without lifting boards or opening masonry. Damp in that wall is the reason the end stays in question. Dry visible timber is genuinely useful: it means the survey is not looking at a floor that is already obviously rotten in the span. It is not a probe of the hidden end.
If the floor is to be relied on, ask a timber specialist to expose the ends where they enter the damp wall, rather than taking the dry spans as the whole storey. Tell the solicitor the ends are still hidden. Do not let a seller sand or decorate the boards and call the bearings inspected. The survey has not confirmed the ends, and it has not said they have failed. Hidden is the finding.
What should you ask your surveyor?
- Which joists could you see, and where do they enter the damp wall?
- Did you see or probe any joist end inside the masonry?
- Are the dry spans clearly separated from the hidden bearings?
What are the typical next steps?
- Treat the joist ends inside the damp wall as still hidden.
- Do not clear those ends because the visible spans are dry.
- Ask a timber specialist to expose the bearings if the floor must be confirmed.
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 there is no beetle flight hole, is the hidden end sound?
No. A lack of flight holes on the visible joists says nothing about the end inside the wall, and it does not even clear the span of every defect. The end is still hidden. Dry timber you can see is not the bearing in the damp wall.
Can a dry meter reading on the skirting clear the joist end?
No. A reading on a skirting is not the joist end built into the wall. The wall the joists enter is damp, and those ends were not seen. The survey has not cleared them from a reading taken somewhere else.