Timber decay and woodworm
One bay of floor is springy where the joists meet the party wall and the ends were not exposed. What decay at those ends is still a guess?
Decay at the joist ends in the party wall is still a guess. One bay is springy where those joists meet the wall, and the ends were not exposed. Spring is a feeling underfoot. It is not a view of the timber buried in or against the wall. The survey has recorded the lively bay. It has not seen rot, beetle or a failed bearing at the ends, and it has not ruled them out. Until the ends are opened, decay there is a possibility, not a finding.
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 built into a party wall are a classic place for hidden trouble, because the bearing is damp and out of sight. They are also a place where a joist can be notched, undersized or poorly seated without any decay at all. The survey cannot pick among those from a bounce. Exposing an end means lifting boards or opening the wall, which this visit did not do. Guessing decay and then pricing it would pretend the ends had been seen. They had not.
If the bay matters, ask a timber specialist to expose the joist ends at the party wall and to say what is actually there. Tell the solicitor the survey felt spring and did not see the ends. Do not describe the wall as rotten. The report has not said that. Decay at those ends remains a guess until someone looks.
What should you ask your surveyor?
- Where was the floor springy, relative to the party wall?
- Were the joist ends left unexposed?
- Is any decay at those ends still a guess rather than a finding?
What are the typical next steps?
- Treat spring at the party wall as a symptom, not as seen decay.
- Do not state that the joist ends are rotten.
- Ask a timber specialist to expose the ends if the bay 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
If the other bays feel firm, are these ends sound?
Firm bays are other bays. This one is springy where the joists meet the party wall, and these ends were not exposed. The survey has not compared hidden timber it did not see. Soundness next door along the floor does not clear this bearing.
Does a historic damp patch on the wall prove the joists have gone?
A patch is a mark on the wall. The joist ends were not exposed, so decay there is still a guess. The patch may be related or may be old decoration. The survey has not joined them into a proved rot. Opening the ends is what would turn the guess into a finding.