Subsidence, settlement and heave
How can shrinkage cracks in plaster be told from a crack you should worry about?
Shrinkage in plaster or a sand-cement render coat is usually a fine, wandering crack in the finish, not a crack that goes through the brick and opens wider at one end. A surveyor who can see it is only in the skim should say so. If they cannot tell, they should not call it subsidence to be safe.
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?
New plaster, a hot room and a cement-rich coat all shrink as they dry. The crack stops at the edge of the patch. Structural movement cracks the masonry as well, may step through joints, and may show inside and outside in the same place. Tapping a hollow patch tells you the finish has left the wall. It does not measure the foundations.
The ABI’s subsidence description is about the ground and the foundations, not about paint. Filling a shrinkage crack is decoration. Investigating subsidence is an engineer or a drain test. Ask the surveyor which layer is cracked. Do not put a structural figure in an offer letter for a crack that never leaves the plaster.
What should you ask your surveyor?
- Is the crack in the paint and plaster only, or in the masonry too?
- Does the same line show outside?
- Is the plaster new, and did you see a straight joint at the edge of a patch?
What are the typical next steps?
- Do not hack off sound plaster to “see the crack” before the surveyor has answered.
- If it is only in the finish, treat it as decoration unless the report says otherwise.
- If the masonry is cracked as well, follow that sentence. Do not let a decorator close it 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 shrinkage happen in a new extension?
Yes. New work dries and moves a little. A crack at the junction with the old house is a known place. It is not automatically subsidence.
Does a crack wider than a pound coin prove subsidence?
Width is a clue, not a diagnosis. The survey should describe the crack. A coin is not a British Standard.