Subsidence, settlement and heave
Why should you not call roof spread subsidence when you write to the seller?
Because they are different mechanisms, and the repair is different. Subsidence, in the Association of British Insurers’ words, is downward movement of the ground affecting the foundations. Roof spread is the roof pushing the tops of the walls out. Underpinning does not tie a roof, and a roof strap does not stabilise bad ground.
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?
The ABI’s consumer pages are about insurance after damage from subsidence, not about how to price a purchase. A buyer who writes “subsidence” on a roof-spread crack may be asked for monitoring, a drain test and an insurance history that belong to a different problem. Use the surveyor’s words. If they said spread, say spread, and ask a structural engineer about the roof.
If the surveyor used both words because they are unsure, the next step is the investigation they named, not a blended discount. There is no honest single percentage for “movement”. Get the right person to look before you name a figure. Your solicitor sends the proposal. The surveyor does not negotiate the price.
What should you ask your surveyor?
- Which mechanism have you actually described in the report?
- What did you see in the loft, if you entered it?
- What investigation would tell spread from foundation movement?
What are the typical next steps?
- Quote the survey. Do not upgrade the noun to subsidence for effect.
- If the loft was not entered, say that. The mechanism may be unproven.
- Ask an engineer which repair they would investigate first.
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
Can a house have both?
Yes. A wall can be pushed at the top and also be on poor ground. That is why the patterns have to be described, not averaged.
Will an insurer pay for roof spread?
Policies differ, and you may not be the insured yet. Ask the insurer. Do not assume the ABI subsidence note covers a roof defect.