Subsidence, settlement and heave
A Leylandii stump sits in the border and an upward crack is in the plinth. Has the survey proved heave?
The survey has not proved heave. A Leylandii stump in the border and an upward crack in the plinth are two observations placed near each other. Heave would be the ground rising as clay re-wets after a tree that was drying it is reduced or gone. A stump plus a crack that runs upward is a pattern worth investigating. It is not a level survey over time, and it is not proof the crack came from swell rather than shrinkage, settlement or old movement. Cause stays open.
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?
Leylandii take a lot of moisture while they are growing. After they are cut, a shrinkable clay can take water back and swell, and that swell can lift light foundations. An upward crack fits that story only as a possibility. The same crack can be historic, can be settlement in the opposite sense, or can be unrelated frost or impact damage. The survey did not take a datum and return. It did not test the soil. The stump explains why the question is asked. It does not answer it.
Tell the solicitor about the stump and the upward crack, and ask what the seller knows about when the tree was removed. A ground-movement specialist can advise on monitoring if you need cause rather than a snapshot. The survey has not started that monitor and has not told you the plinth is lifting. Do not tell a lender heave is confirmed. Equally, do not let anyone delete the crack because the cause is unproved. The two facts stay on the page together, unresolved.
What should you ask your surveyor?
- Has heave been proved, or only a stump and an upward crack recorded?
- Were levels taken on more than one visit?
- Could the crack be old movement rather than swell?
What are the typical next steps?
- Treat heave as unproved.
- Tell the solicitor when the Leylandii was removed, if the seller knows.
- Ask a specialist about monitoring before you call the cause certain.
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 an upward crack be something other than heave?
Yes. An upward crack can be old, can relate to shrinkage or settlement, or can have a local cause. Heave is one mechanism that fits a stump in clay, and it was not proved. The survey did not test the soil and did not watch the crack move. Keep several causes open. The photograph of an upward line is not a seasonal swell record.
Did anyone establish a datum and come back to it?
No. Proving heave needs levels over time, and this was a single visit. No datum was established and no return reading exists. The stump and the crack were recorded together. That is a reason to ask questions. It is not a graph of rising ground. Without the return visit, movement direction stays unknown.