Subsidence, settlement and heave
The crack is in the plaster and the surveyor could not see a matching crack in the brick. Why is a plaster crack not yet a structural diagnosis?
Because the structure that would carry the diagnosis was not seen to be cracked. The crack is in the plaster, and the surveyor could not see a matching crack in the brick. The survey has recorded a plaster crack and that limit. It has not diagnosed a structural crack in the masonry. Plaster cracks from shrinkage, heat, a poor key and ordinary decoration. Until a crack shows in the brick, or the plaster is opened and the brick is found cracked, the structural claim has not been made. A finish crack is not yet that diagnosis.
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?
Old lime plaster and modern gypsum both craze and open along board edges without the wall behind them moving. A structural crack is a crack in the supporting fabric: brick, block or the frame. The surveyor looked for a match and could not see one. That negative finding is the point. It does not prove the brick is perfect behind intact plaster elsewhere, and it does not condemn the wall where the only crack is in the coating. The diagnosis waits on the masonry, which this crack has not shown.
Ask the surveyor where they looked for a brick crack, and whether furniture, tiles or a lining stopped them. If a lender or an insurer has been told the wall is structurally cracked, correct that to the survey's words: plaster only, brick not seen to match. Opening the plaster is a further step, agreed with the seller, not a conclusion already reached. Do not price a structural repair off a finish crack the inspection would not call structural.
What should you ask your surveyor?
- Was the crack confined to the plaster?
- Where did you look for a matching crack in the brick, and what stopped you?
- Are you withholding a structural diagnosis until the masonry is shown to be cracked?
What are the typical next steps?
- Call it a plaster crack with no matching brick crack seen.
- Do not upgrade it to a structural diagnosis.
- Open the plaster only if the brick itself must be checked.
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 plaster crack is wide, does width make it structural?
No. A wide split in plaster can still be a finish crack. Width in the coating is not a crack in the brick. The surveyor could not see a matching brick crack, so the structural diagnosis has still not been made.
Does sound brick beside the crack clear the whole wall?
It clears only what was seen. Brick that showed no crack at that spot supports the limit of the note. It is not a survey of every hidden face, and it does not turn the plaster crack into a structural one.