Cottage on the cliffs

Could Your Dream Cornish Cottage Be Sitting on a Copper Mine?

Being generally of a northern persuasion, we must admit that Cornwall can sometimes feel like a bit of a dream to us. Like you, when we think of it, we often imagine picturesque cliffsides, gorgeous beaches, delicious pasties, cream teas…. and extra conveyancing searches.

Alright, alright, we’ll admit that the extra searches might be a niche one. However, if you’re hoping to buy property in Cornwall, there’s something you’ll need to know about too.

So what’s the deal with the searches?

You may know searches as one of the cornucopia of annoying things your conveyancer sends you emails about during a property purchase. It’s true that they can be a bit dull, but they’re also a vital part of ensuring you’ve got all the information you need about a property before you legally commit to buying it.

As part of your purchase, your conveyancer will need to submit searches to the local authority to find out key information about thrilling topics such as sewage connectivity, planning consent and historical contamination. In certain parts of the country, your conveyancer will need to carry out extra searches to investigate more specific risks and concerns.

In Cornwall, these specialist risks (isn’t that a nice way of saying it?!) concern mines of the tin, copper and China clay variety. It may also be necessary to carry out these searches for properties elsewhere in the South-East, including in some parts of Devon and Somerset.

A brief history lesson

If you’ve watched any of the BBC’s Poldark – and if you’ve managed to tear your eyes away from Ross and Demelza – you’ll know that Cornwall has a long history of mining.

Cornish mining dates all the way back to the Bronze age, when tin and copper were first discovered in the area. This continued for hundreds of years, peaking in the 18th Century, when China clay was added to the mix. For a time, Cornwall was the mining centre of the world, though the industry declined over the 19th and 20th centuries.

It’s possible to visit some of these old mining sites; many of which are designated as UNESCO World Heritage Sites. However, many more were simply sealed shut once they were no longer needed.

Why do we need to worry about this?

The thing about a sealed mine is that it often leaves no trace on the surface. Problem is, we can’t say the same thing about the miles upon miles of tunnels and shafts beneath our feet. Some abandoned mines have been capped with wood or backfilled with waste, others have been left exactly as they were when the last miner walked out. Without a specialist search, you’d have no idea that the tunnels and shafts were there – or what condition they’d been left in.

Now, it’s all very well thinking that what you don’t know won’t hurt you… but in this case, we’re afraid it could.  

At the worst end of the spectrum, an abandoned mine under your property could collapse. If this was to happen, your cute Cornish cottage would likely be at risk of subsidence or other types of significant damage.

Having a historic mine nearby can also have environmental implications. It’s possible for explosive gases to build up in abandoned shafts and tunnels, and any water flowing through them can become contaminated. (If you’re in any doubt about how seriously to take this, it might be prudent for us to mention that Cornish mines were also key producers of arsenic.)

All of these risks mean that if a property is located in the vicinity of an old tin, copper or China clay mine, it’s likely to be worth less than it would be otherwise.

Oh, and one last thing…

If you were to discover old mines in the vicinity of your intended abode, this could well open an additional can of worms. In the past (particularly between 1900 and 1960), house builders in Cornwall sometimes used mundic bricks.

Now, you might well be asking what on Earth are mundic bricks when they’re at home. Essentially, mundic is a kind of concrete mixed using waste products from the mines. Over time, the chemicals in this waste can degrade the concrete from this inside and cause it to crumble.

Funnily enough, mortgage companies are often keen to know the properties they’re financing don’t contain mundic bricks. Though Cornish mining searches won’t tell you whether or not mundic bricks were used in the construction of the property, the closer it is to a mine, the more likely this might be. In these situations, it may be necessary to commission a further survey.

If you’re confused about copper and China clay, terrified about tin or musing on mundic, please don’t hesitate to get in touch. We’re always on hand to guide you through the process of carrying out specialist searches and interpreting the results. We might even refrain from referencing Poldark, if you’re lucky.

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