Electrics and gas
A flue from a fire passes through a bedroom ceiling in a boxing that is warm. What clearance inside that boxing was not measured?
The clearance inside that boxing was not measured. A flue from a fire passes through the bedroom ceiling, and the boxing around it was warm to the note of the visit. Warmth may be ordinary heat from the flue or a sign the casing is close to the pipe. The survey has not opened the boxing, has not measured the gap to the timber or the plaster, and has not tested the flue. Gas safety and flue clearance are a different inspection from recording a warm box.
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 flue through a bedroom has to keep a gap from anything that can scorch, and the boxing is what hides that gap. Feeling warmth on the casing tells you heat is arriving at the surface you can touch. It does not tell you the distance from the flue pipe to the nearest timber inside. The survey could not see that distance without opening the box, and it did not open it. A warm bedroom is not a measurement, and it is not a certificate that the flue is acceptable.
Ask a Gas Safe engineer, or the appropriate solid-fuel specialist if the fire is not gas, to inspect the flue and the clearance inside the boxing. Tell the solicitor the survey records a warm box and an unmeasured gap. Do not tell a lender the flue was passed because the bedroom was only warm, not hot. The home survey has not produced a gas or flue certificate.
What should you ask your surveyor?
- Was the warm boxing opened, or only felt from the bedroom side?
- What clearance between the flue and the boxing was left unmeasured?
- Did you record the warmth without a flue or gas-safety test?
What are the typical next steps?
- Treat the clearance inside the boxing as unmeasured.
- Ask a registered engineer to inspect the flue and the casing.
- Do not read warmth in the bedroom as a passed flue.
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 boxing is only warm, not hot, is the gap adequate?
Not on that feeling. Warmth shows heat at the surface you can touch. The survey did not open the boxing and did not measure the gap to timber inside. A mild surface can still hide a close pipe. The home survey has not decided the clearance, and it has not certified the flue.
Does a tidy painted boxing mean the flue route is acceptable?
No. Paint shows the bedroom finish, not the gap inside. The survey saw a warm boxing where the flue passes the ceiling and did not measure clearance. Decoration does not test the flue and does not become a gas-safety record. The route through the bedroom stays undescribed beyond what was visible.