Subsidence, settlement and heave
A stump remains and the new paving beside it has lifted. What can the survey judge from the slabs, rather than from a crack in the wall?
It can record the stump, the lifted or rocking slabs, and that the paving is new, a pattern that can fit heave after a tree was removed on clay. That is not a measurement of the house and it is not a crack diary. The survey does not test the soil, so lifted paving speaks about the patio, not about whether the walls have moved.
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?
Heave is the ground swelling, and it can follow the removal of a tree on clay because the soil takes up moisture the tree used to draw. The Association of British Insurers describes subsidence as the opposite idea: downward movement of the ground. A stump tells you a tree was there and was cut. New slabs that no longer sit flat tell you something has disturbed the bedding since they were laid. Roots left under a patio, poor sand bedding, or frost can lift slabs as well. The surveyor cannot sort those causes by standing on the patio once.
Keep the paving sentence separate from any crack in the brickwork. Do not argue the house from the slabs, and do not ignore the slabs because you are staring at a wall. Ask whether doors or floors inside were distorted near that corner. If they were not seen to be, say so. Relaying the patio is a groundwork job for a landscaper after you know you are not about to bury evidence an engineer wanted. Nobody on this inspection measured soil moisture. Nobody should invent how many millimetres the clay will still rise.
What should you ask your surveyor?
- Which slabs have lifted, and how close are they to the stump?
- Did you see matching distortion in the walls or the floors, or only in the patio?
- Are you calling this heave, or only recording a stump and uneven new paving?
What are the typical next steps?
- Photograph the slabs and the stump before anyone relays the patio.
- Do not tell the lender the house has heaved because a patio rocks.
- If an engineer is asked about heave, give them the paving description as paving, and the wall description as walls.
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
Should the stump be ground out so the slabs sit flat?
Not as a first move copied from the survey. Grinding roots can be the wrong step if someone still needs to see the ground. Ask before you instruct it.
Does old paving that is still flat clear the stump?
No. Flat slabs mean those slabs have not lifted. They do not test the clay under the footing.