New builds and warranties
A steel lintel in the new garage is unpainted and already showing rust. What corrosion protection was not recorded as complete?
The corrosion protection of that steel lintel was not recorded as complete. The survey saw an unpainted steel lintel in the new garage, already showing rust. Paint, galvanising, or whatever coating the specification expected, was not noted as finished. Rust on a new lintel is early corrosion of bare or unprotected steel, not a completed protection system. The report has not specified a product, and it has not said the lintel has lost its strength. NHBC describes Buildmark as a 10-year warranty and insurance product. The survey has not opened a claim about the coating.
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 steel lintel over a garage opening needs a coating if it is to sit in a damp, unheated space without rusting from the start. Unpainted steel that is already marked has not had that protection finished, or the protection has already failed where you can see it. The survey recorded the face of the lintel. It did not measure section loss, test the steel, or read the plot specification to see which coating was promised. Incomplete protection is the observation. A new coating design is not.
Tell the developer the garage lintel is unpainted and rusting, and ask for the corrosion protection in the specification to be completed or made good. Ask the solicitor which warranty applies and whether a coating defect is something that policy deals with. NHBC's Buildmark is a 10-year warranty and insurance product. The survey does not open a claim. Do not treat light rust as a verdict that the lintel must be replaced. That judgement is not in the report.
What should you ask your surveyor?
- Which garage lintel is unpainted and showing rust?
- Was corrosion protection left unrecorded as complete?
- Did you leave strength, and any coating specification, untested?
What are the typical next steps?
- Report the unpainted, rusting lintel as incomplete protection.
- Ask the solicitor which warranty policy covers this plot.
- Do not read the note as a decision to replace the lintel.
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 rust is only on the surface, is the protection finished?
Surface rust is still rust on a new lintel that was seen unpainted. The survey did not record the corrosion protection as complete, and it did not measure how deep the rust goes. A light bloom is not a finished coating. It is also not, by itself, a statement that the steel has failed. The protection remains the incomplete item.
Does rust in the garage mean the house lintels are the same?
Not on this note. The finding is one steel lintel in the new garage. The survey has not inspected every lintel in the house for a coating or for rust, and it has not recorded their protection as incomplete. Keep the garage lintel as the item. Do not spread one unpainted member across openings that were not described that way.