Wall ties and cavity insulation
What should you ask if replacement wall ties have already been installed?
Ask for the guarantee, the number of ties, and whether the old ties were isolated or left to keep expanding. New plugs on the face show that someone has worked on the wall. They do not show that every old tie has stopped doing damage.
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?
Replacement ties are usually fixed from outside and the holes pointed up. A surveyor can see the pattern of making-good if it is still visible. They cannot see whether the specification matched this cavity, or whether insulation was in the way. A paper guarantee may sit with the seller. Read the exclusions. Many are insurance-backed only while the premium was paid, and the survey will not police that.
The Energy Saving Trust still wants the wall to be suitable before anyone adds cavity insulation. Ties and insulation interact: fill can hide the remaining metal. If you are told the wall was tied and then filled, ask for both sets of paperwork, and ask the surveyor what they could still see.
What should you ask your surveyor?
- Could you see the pattern of replacement ties, or only a seller’s claim?
- Were the old ties isolated, or is that not known?
- Was the cavity filled before or after the ties were replaced?
What are the typical next steps?
- Ask the seller for the guarantee and the specification, and read the address on it.
- Do not assume a guarantee transfers. Ask the issuer.
- If there are new horizontal cracks after the work, treat the guarantee as something to call in, not as proof the movement has stopped.
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
Do new ties need building regulations?
Ask the local authority or the installer what was notified. The survey does not issue that approval.
Can you retrofit ties with insulation already in the cavity?
Sometimes, but it is harder and easier to get wrong. The survey has not designed the method. Ask a specialist who will say how they deal with the fill.