Non-standard construction
A rust stain runs down from a Cornish unit post and the panel beside it is quiet. What reinforcement inside that post was not exposed?
The reinforcement inside the Cornish post was not exposed. A rust stain runs down from the post, and the panel beside it is quiet, so the survey can describe the stain and the quiet panel. Rust on the surface can come from steel inside the post, but the inspection did not open the post, expose the bar, or measure any loss of steel. A stain is not an exposure of the reinforcement. The panel being quiet does not clear the post.
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?
Cornish units use concrete posts and panels, with reinforcement in the posts. A rust stain tracking down from a post is a surface clue that steel somewhere in that post is corroding enough to stain the face. The clue stops at the stain. Opening the post to see the bar is a different and more destructive step, and this survey did not take it. A panel that shows no crack is a note about the panel. It is not a window into the post beside it.
Tell the solicitor there is a rust stain from a post and that the reinforcement was not exposed. If a lender asks about the Cornish construction, give them that limit rather than a clean bill for the steel. A specialist in these concrete houses can advise whether any opening is warranted. Do not chip the post open yourself. The survey has not seen the bar.
What should you ask your surveyor?
- Was the reinforcement inside the post left unexposed?
- Did the quiet panel stay a note about the panel, not the post?
- Is the rust stain a surface clue rather than a view of the steel?
What are the typical next steps?
- Describe the rust stain, not an exposed bar.
- Do not treat the quiet panel as a clearance of the post.
- Ask a specialist before anyone opens the Cornish post.
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 stain is faint, is the steel intact?
Not on the strength of a faint stain. Faint or strong, the stain was seen from outside. The reinforcement inside the post was not exposed, and no loss of steel was measured. The bar itself stayed hidden. Surface colour is not a section through the post.
Does a quiet panel mean the neighbouring post can be ignored?
No. The panel being quiet describes the panel. The rust stain runs from the post beside it. That post's reinforcement was not exposed, so the panel does not clear it. Quiet concrete next door is a different member, and it does not open the post.