Wall ties and cavity insulation
What is a cavity closer, and why is it not a wall tie?
A cavity closer seals the cavity at an opening, such as a window or a door, so the two leaves are closed off and the jamb does not act as a cold bridge. A wall tie holds the leaves together across the cavity in the body of the wall. Seeing a closer, or not seeing one, says nothing about whether the ties have corroded.
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?
Missing or rotten closers show up as draughts and cold reveals, and sometimes as damp at the frame. Failed ties show up, when they show up at all, as regular cracks or a bulging leaf. A surveyor who mentions one is not automatically talking about the other. On a visual inspection the closer may be hidden by the frame. The ties are hidden in the cavity.
Do not let a quote for new ties be justified by a draughty window, or a quote for new windows be justified by a tie comment, unless the surveyor actually linked them. They are different elements. The Energy Saving Trust’s notes on cavities are about insulation, not about closers.
What should you ask your surveyor?
- Are you commenting on closers at the openings, or on ties in the wall?
- Could you see the closer, or only the frame?
- Is any crack pattern the regular horizontal pattern associated with ties?
What are the typical next steps?
- Brief contractors with the sentence from the report, not with a merged version.
- Do not replace windows solely because ties were mentioned, or the reverse.
- If both are suspected, ask for two scopes so the quotes can be compared.
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
Does a plastic closer prove the ties are plastic too?
No. Closers and ties are specified separately. One can be plastic and the other metal, or either can be hidden.
Can a missing closer be called rising damp?
It can wet a reveal. That is not water rising from the ground. Ask the surveyor which pattern they saw.