Age and type of house
Original Crittall windows sit in a 1930s cavity wall and condensation runs on the metal. Why is that cold metal a condensation note rather than a failed cavity?
The cold Crittall metal is a condensation note, not evidence that the cavity has failed. Original steel windows in a 1930s cavity wall run with condensation because the frame is a cold bridge. Moisture from room air lands on that cold metal. That is not water crossing a failed cavity, and it is not evidence that the wall ties have failed. The survey has recorded condensation on the Crittall. It has not tested the cavity, the ties or the steel beyond what it could see.
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 wall of this period has two leaves and a gap. Condensation on a metal frame is water from room air meeting a frame colder than the plaster. Beads can form on the steel while the cavity does its ordinary job. The survey did not open the cavity and did not test the ties. The drips on the metal stay labelled as condensation.
Ask the surveyor to keep the wording as condensation on the Crittall frames if that is what was seen, so a lender does not read a cavity failure. Dealing with the cold metal is a window and ventilation question, not a wall-tie survey. Do not inject the cavity because the frames run with water. The home survey has not found a failed cavity, and it has not tested one.
What should you ask your surveyor?
- Is the water on the Crittall a condensation note?
- Why is that not a finding that the cavity has failed?
- Were the wall ties left untested?
What are the typical next steps?
- Label the runs on the metal as condensation.
- Do not rewrite that note as a failed cavity.
- Keep any window work separate from a wall-tie investigation.
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 sill is stained, has rain crossed the cavity?
Not on this note. A stained sill can collect the condensation that runs off the cold metal. The survey has not shown water crossing the cavity, and it has not tested the ties. The sill stain fits the condensation path.
Does new double glazing in one bay clear the Crittall note?
Only for the window that was replaced. Original Crittall frames that remain are still cold metal. Condensation on those frames is still not a failed cavity, and the survey has not tested the wall. One new bay does not regrade the cavity.