Damp and moisture meters
Condensation sits on a metal window frame and the wall beside it is dry. Why should that not be written up as penetrating damp?
It should not be written up as penetrating damp because the moisture is on the metal frame and the wall beside it is dry. Condensation forms on a cold surface when room air meets it. A metal window is a cold frame. Water on that metal, with dry plaster next to it, is sitting on the frame rather than arriving through the wall from outside. The survey has recorded condensation on the frame and a dry wall. It has not called that penetrating damp, and it has not tested the cavity or the frame joints as a leak.
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?
Penetrating damp is water coming through the fabric from outside, and it marks the wall, the reveal or the ceiling in the path of that leak. Condensation on a metal frame beads on the cold metal and can drip onto the sill without wetting the wall beside it. A dry wall is the reason not to promote the bead into a penetration note. The survey saw where the water was. It did not measure humidity, and it did not hose the outside of the window.
Tell the solicitor, and any contractor, that the survey separates frame condensation from a dry wall. Do not buy a damp-proofing treatment for penetrating damp on the strength of water on the metal. Better ventilation, or a less cold frame, is a different conversation, and the survey has not specified a new window. If the wall later marks after rain, that would be a new observation. It is not what was written from a dry wall and a wet frame.
What should you ask your surveyor?
- Is the moisture on the metal frame, with the adjacent wall dry?
- Have you kept this off a penetrating-damp description?
- Was the cavity left untested?
What are the typical next steps?
- Describe the moisture as condensation on the metal frame.
- Do not brief it as penetrating damp through a dry wall.
- Do not commission a damp treatment from this note alone.
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 the diagnosis changed to a leak?
A stained sill can be drips from the frame, which still fits condensation on cold metal. The survey's point is the dry wall beside the frame. That dry wall is why this should not be written up as penetrating damp. Ask what was seen on the sill. Do not upgrade a dry wall to a leak without a new look.
Does a metal frame always mean the sealed unit has failed?
No. Condensation on the frame is on the metal, not a failed sealed unit. Mist between panes would be a different note. The wall beside this frame is dry, which is why the frame moisture should not be written up as penetrating damp. The survey has not condemned the glass. It has located water on a cold frame.