Subsidence, settlement and heave
Does a cracked kitchen screed, with the outside walls still plumb, mean the house is subsiding?
No. A crack in a screed or a tented tile is damage to the floor finish or the slab, and plumb outside walls only mean the shell was not leaning where the surveyor looked that day. Neither fact proves downward movement of the ground, and neither fact clears it. The survey does not test the soil, and one visit does not monitor the floor.
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?
Ground-bearing slabs and screeds crack because they shrink, because a heating pipe expanded, or because the fill under them settled locally. Tiles tent when the adhesive loses its grip or the slab cups. Those are floor defects. They are not automatically the same event as the walls leaving their footings. The Association of British Insurers describes subsidence as downward movement of the ground. A plumb wall is only what could be seen without a long-term level survey. A crack in a kitchen floor can sit in a house whose walls are still straight.
Ask which floor was cracked, whether the crack continues into the walls, and whether the surveyor could see the construction under the screed. They usually cannot. A standard inspection does not take up a floor to prove what is below. Do not price a new foundation from a cracked tile, and do not ignore a crack that leaves the screed and steps into the brick. Those are different sentences. Write them separately to any contractor. The report has not become a soil investigation because the kitchen floor looks wrong.
What should you ask your surveyor?
- Does the crack stay in the screed, or does it enter the walls?
- Were the outside walls plumb where you looked, and where did you not look?
- Could you see what is under the screed?
What are the typical next steps?
- Do not replace the floor and call it underpinning.
- Do not ignore a crack that steps from the floor into a wall. Ask for that to be described on its own.
- If you need the fill under the slab understood, that is an opening-up the seller must agree, not a guess from the tile.
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 slab settle while the walls stay put?
Yes. The slab and the walls may not share the same support. The survey can suspect that. It cannot measure the fill.
Does a plumb wall on one visit mean it will stay plumb?
No. It means it did not look out of plumb where it was seen. It is not monitoring.