Wall ties and cavity insulation
The inner leaf is cracked and the outer leaf the surveyor could see is not. What does that split not decide about the wall ties?
It does not decide the ties either way. The inner leaf is cracked and the outer leaf the surveyor could see is not, and that split is a difference between two leaves, not a tie test. The survey has recorded which leaf is cracked and the limit of what could be seen outside. It has not tested the ties, and it has not decided that they have failed or that they are sound. Tie corrosion more often marks the outer leaf, so a quiet outer face does not convict the ties and does not clear them. The split leaves the tie question undecided.
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?
Cavity ties connect the two leaves. When they corrode they often expand in the outer bed joints and crack that face, which is why an inner crack with a quiet outer leaf is an awkward fit for the usual tie storey. Awkward is not a verdict. The inner crack may be a lintel, a partition, shrinkage or a point load, and the outer leaf may be cracked where the surveyor could not see, under render or on a return. The visit did not open the cavity.
Ask the surveyor how much of the outer leaf was actually in view, and what else might explain the inner crack. Do not tell the solicitor the ties have failed, or that they have passed, on the strength of this split. If the tie question still matters, it needs an inspection that finds and tests ties. A lender should see an inner crack and an outer leaf that looked quiet where it was seen, which is all the survey decided.
What should you ask your surveyor?
- How much of the outer leaf could you actually see?
- Did you test any tie, or only compare the two leaves?
- Does this split leave the ties undecided?
What are the typical next steps?
- Record an inner crack and a quiet outer leaf where it was seen.
- Do not decide the wall ties from that split.
- Test the ties only if that separate question still needs an answer.
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 inner crack is over a door, is that the lintel instead?
It may be, and the survey has not had to choose for the ties. A crack over a door can belong to the opening. That possibility is one reason the split does not decide the ties, which were not tested.
Does pebble-dash on the outer leaf count as quiet?
Only if the surveyor could see no crack in it, and dash hides a lot. Quiet where it could be seen is not a test of the ties, and hidden outer-leaf cracks remain unseen. The ties stay undecided. Keep the split between the leaves inside the facts the surveyor actually recorded on the day.