Subsidence, settlement and heave
What can one survey visit say if floor joists bear on a party wall that appears to have dropped?
It can record a slope in the floor, a gap at the ceiling, or joist ends that look to sit on a wall lower than the wall opposite. It cannot measure how far that party wall has dropped, and it cannot say the drop is still going on. The joists were not uncovered. One visit does not monitor the wall, and the survey does not test the soil.
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?
In a terrace, joists often span from the party wall to a spine wall or to the other party wall. If one support drops, the floor tilts and the cornice or the skirting can open. That pattern is a reason to take the comment seriously. It is not a figure for how much the ground has moved. The Association of British Insurers describes subsidence as downward movement of the ground. A sloping floorboard is compatible with that and also with an old dropped support that has been still for years. The inspection cannot choose.
The surveyor has not lifted the floor to see every bearing, and a standard inspection does not open up concealed structure to prove it sound. Say that clearly to anyone who wants to price a new wall. The neighbour’s side of the party wall was not inspected. The survey does not instruct work on that side and does not decide who pays. Your solicitor asks about any known history. If you need an engineer, give them the surveyor’s description, not a storey you have added about the ground.
What should you ask your surveyor?
- Which end of the joists looks lower, and what did you actually see of the bearings?
- Is the slope in one room, or does it continue through the house?
- Are you saying the party wall has moved, or only that the floor is out of true?
What are the typical next steps?
- Do not lift floorboards before you own the house unless the seller agrees in writing.
- Tell the solicitor the neighbour’s side was not seen.
- If an engineer is instructed, ask them to distinguish a historic drop from movement that is still active. This report has not done that.
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
Does a gap under the skirting on the party wall prove the joists have left their sockets?
No. Skirtings are nailed on. A gap can be shrinkage of the board. Ask whether the joist ends were seen at all.
Can you prop the floor from the survey sentence?
No. Propping is a builder’s or engineer’s instruction after they have seen the bearings. The survey has not designed it.