Wall ties and cavity insulation
The report says the cavity width was not measured. Why can nobody then take a tie length from the survey and order parts?
Because the length of a tie depends on the cavity width, and that width is not in the report. The survey says the cavity width was not measured, so there is no figure to add an embedment to and no length to order. The inspection has recorded the absence of a measurement. It has not estimated a width, and it has not specified a tie. Ordering parts from a sentence that says 'not measured' invents the number the surveyor withheld. Nobody can take a tie length from this report, because the report does not contain one.
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?
A cavity tie has to cross the gap and sit properly in both leaves. Leaves vary, cavities were built to different widths, and insulation or a crooked joint changes what a tape would read at one spot. Without that reading, a supplier's 'usual' length is a guess about a different wall. The survey is right to leave the blank rather than dress a guess as a measurement. A blank cannot be turned back into a measured length by a buyer who wants to get on and order.
Ask the surveyor to confirm the width is absent and that no range was intended. Do not let a contractor write a length onto the survey as if it had been taken. If ties are to be ordered, the person who specifies them measures the cavity, which is their job and not a footnote to this paragraph. Tell the solicitor the report cannot be the source of a tie length. A lender should not be told the ties have been sized.
What should you ask your surveyor?
- Is the cavity width simply not measured, with no figure implied?
- Did you give any range that someone might treat as a length?
- Would you expect a tie to be ordered from this report?
What are the typical next steps?
- Leave the cavity width as not measured.
- Do not derive a tie length from the survey.
- Have the cavity measured before any ties are specified.
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 cavity is visible at a meter box, can that gap be the length?
Not as a tie length taken from the survey. A glimpse at a meter box was not written up as a measured width. The report says the width was not measured, so the order still cannot come from it. No extra conclusion about the unmeasured cavity should be read into the wording.
Does a standard house of this age have one cavity width?
The survey did not say so, and it did not measure this one. Age is not a width. Parts still cannot be ordered from the report, because the figure is not there. The inspection did not stretch the unmeasured cavity into any wider claim at all.