Non-standard construction
Nothing on the visit sampled a capped shaft, opened the Cornwall garden or tested a mundic class the cap does not provide. What has to stay undecided?
The mundic class has to stay undecided, because a capped shaft does not provide one. Nothing on the visit sampled the cap, opened the Cornwall garden, or tested the concrete of the house. A shaft cap is a cover over an old ground opening. Mundic is a question about certain concrete, and RICS guidance on it is for surveyors in the south west. Cornwall Council describes a core test and does not provide it. A home survey does not drill cores or award Class A, B or C. The cap and any class for the walls stay separate, and both are undecided as a test.
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 cap in a Cornwall garden tells you there is a cover. It does not describe the aggregate in the walls of the house. Sampling the cap was not done, and the garden was not opened, so even the shaft itself was only seen at the surface. A class would depend on cores of the relevant concrete, which this visit did not take. The council describes that test and does not offer it. What stays undecided is both the shaft beyond the cap and any class for the building.
Tell the solicitor the capped shaft was not sampled and that no mundic class was given. A Coal Authority or other mining search, if the shaft needs one, is a different product from a concrete classification. Do not let the garden cover stand in for cores of the walls. If classification is required, instruct the people who take and test cores. This home survey has not drilled them and has not awarded Class A, B or C.
What should you ask your surveyor?
- Was the capped shaft only seen at the surface?
- Did any part of the visit test concrete in the house?
- Why can the cap not stand in for a mundic class?
What are the typical next steps?
- Keep the shaft cap separate from any class for the walls.
- Tell the solicitor nothing was sampled and no class was awarded.
- Instruct a core test separately if a class is actually required.
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
Does a tidy cap mean the garden has no mining history?
No. A tidy cap only means a cover was seen. The visit did not sample it or open the Cornwall garden, so what lies under the cap stays unknown. That unknown is also not a mundic class. A home survey does not award Class A, B or C from a garden cover, and this one has not done so.
Should the house walls be assumed clear because the cap is outside?
No. The cap being in the garden does not clear the walls, and it does not condemn them. Mundic class, if it is needed, comes from cores of the relevant concrete. RICS guidance is for surveyors in the south west. This visit did not drill those cores. Cornwall Council describes a core test and does not provide it.