Mining – How it Affects Property in Cornwall

Part of Cornwall’s rich heritage lies in tin mining – as illustrated by the engine houses dotted around this beautiful county. Miners worked in some desperate conditions in various locations across Cornwall to extract tin, copper and other precious minerals. With its rich geological make-up, Cornwall was one of the more important mining areas across Europe until early in the 20th century.

While mining was widespread across Cornwall, the most notable tin mines in West Cornwall have to be Geevor Tin Mine in Pendeen and Levant Mine near Trewellard. Both mines were functioning in to the 20th century with Levant Mine closing in 1930, and Geevor working right up until it closed in 1986! 

Mining was dangerous, and was for the most part a very manual process. Conditions were tricky, and men were working at great depths below ground and sometimes below the sea in Cornwall to extract tin, copper and any byproducts that could be monetised.

The scars of mining are visible in Cornwall’s varied landscape with areas around Geevor relatively untouched. You can walk along the coast path near Pendeen and see the huge piles of red rocks and earth dug out from beneath the surface to try and locate veins or lodes of minerals that could be removed and sold.

When an area of minerals (or a lode) was discovered by miners, they would excavate the area to extract as much as possible. Hundreds of years ago this was done from the top down, so digging down from the surface to locate and follow the rich veins of minerals and latterly when technology and machinery had improved, this was done the other way, by digging down below the vein of minerals and working back up towards the surface.

As materials were removed underground to make space for operations and to navigate to the lode, workers would backfill the mine working above that had been created on the surface. Timbers would be laid across the void, and rubble, soil and rocks would be emptied in to bring the ground level back to normal. Over the years since this back-filling those timbers have begun to fail, and materials obviously began to shift. 

Historic tin mining operations make buying property in Cornwall quite challenging sometimes, and as part of the conveyancing process your solicitor will request a mining search of the area of the property you are buying. This mining search can be done independently of the solicitor and companies can produce a mining search report online for you if you want to check this yourself before proceeding any further.

Mining search reports will highlight anything that is known or suspected in the vicinity of the property, and typically mortgage lenders will want this to be all clear before approving a mortgage. If mine workings, suspected or confirmed, are found to be within the perimeter or boundary of the property you are buying in Cornwall, then your solicitor will recommend further investigation.

There are two possible outcomes following a mining search that shows the presence of something, and either a visual site survey or investigative drilling will be required, depending upon how serious or widespread it looks.

A site survey is easy to arrange with a mining consultancy or an engineer familiar with mining. The engineer will look for signs of subsidence or ground instability and produce a report that either confirms the property is not at risk of subsidence due to mining, or it will recommend further investigations IE drilling.

Investigative drilling is a more involved process, and depending upon the location and positions of any mining features, can take days of planning and drilling – all at a much higher cost than the visual site survey. The drilling will take samples of the soil and rocks, but will also map out where any features are likely to be and run. This will result in a report that either confirms the features present little or no risk to the structure of the building, or will render the property unmortgageable by most high street lenders. 

Properties that have mining features like shafts, adits or stopes within their boundary are seen as high risk, and very often you will see these properties in Cornwall marked as “Cash Buyers Only”.