To try and dig into a cave below my house?

[TimeToChangeNameAgain]

There’s a small network of caves in my town which were open as showcaves until the 80’s but then all shut off. The dad of my dc’s best friend is a keen caver type person and showed my dh a map of these caves which appear to go directly under our garden.

The pair of them plus 4 kids have been in the garden all weekend and managed to dig what looks like a grave. At the moment I’m leaving them to it because I’m assuming they’ll lose interest soon and they’re not actually going to find this bloody cave. The dc’s are so excited about it - convinced that they’re going to have it as the best den ever and find loads of fossils.

They won’t actually suddenly fall into a cave will they? The stuff I can find about the original caves says that they’re granite and limestone - they’re just digging through earth and a few stones at the moment. I’m assuming they would have to actually chisel away loads of rock before they hit a cave but I’m completely clueless. I really don’t care about them digging a hole in the garden but I don’t want them to actually find anything.

Would you try to stop them? Or just leave them digging? They won’t start up again until next weekend and I’m hoping they’ll have lost interest by then and I can turn their grave into a little pond.

The question is: would anybody pay heed to you, if you tried to stop them?

Digging deep holes can be very, very dangerous, never mind the damage it might cause to your property. This whole scenario is daft. I would put an end to it.

If it was just a bit of earth separating your garden from a massive cavernous space, it would have caved in already. They're not going to get anywhere. 😂 I'd leave them to their fun, though.

Thank you for this OP, this is exactly the kind of content I want to be reading on Mumsnet on a Sunday night

I think I'd just leave them to it, although I'd be more worried that they'd find the caves and then you'd have all and sundry wanting to come and explore the caves via your garden..

Hopefully you'll just have a big grave pond at the end of it.

Unless you have salt water intrusion, you have nothing to worry about.

Oh you have to let them dig for our entertainment and we definitely need pictures

"Day one of the dig. RIP Rover the dog"

How far away is the digging from the house? if it's close to the house I would shut down any further excavation until a structural engineer has given it the once over.

At least we know where to come if a mumsnetter doesn't have a patio and it sound as if there may be space for more than one in that hole.

Right, so how deep is this hole? And what sort of soil are you on? Once they get deeper than 4 foot or so there is a good chance of cave in and if you're kids are scrabbling in the bottom when that happens they could quite easily be killed. So either look to shore up the sides properly or stop digging.

What @Porcupineinwaiting said.

Unless one of them is an actual qualified gravedigger, they are going to get into potentially fatal difficulties very quickly.

Doesn't the map show the depth of the cave? It's probably several metres below ground, if not a lot more than that.

Be careful OP. This is where unrestricted digging can lead to:

www.plaquesoflondon.co.uk/page2706.htm

Aside from the very real danger of collapse, there is also the very real danger of them hitting an electrical cable or other utility. If they are lucky, it’ll be the gas, water or drainage and it’ll be messy and expensive but no one will die. If they hit the electrics though, well that’s another story.

And you can’t trust any cable diagrams as they are notoriously inaccurate. That’s why construction workers use equipment to detect where the cables ACTUALLY are compared to where the map SAYS they are.

It’s a ridiculously dangerous idea in so so many needlessly tragic ways

They won't fall into the cave unless there's a blocked entrance into it in the garden. Caves have roofs of rock.

It sounds like they are trying to dig into an existing system rather than simply excavate a hole. There are caves underneath things - there's a cave whose entrance is just outside the farmhouse kitchen window, there's one under Chepstow racecourse, there's another under the A66, close enough that you can hear the traffic above you.

Cave exploration in the UK consists largely of digging glacial debris out of cave passages and potholes - cave explorers get rather good at shoring up stuff.

Shamelessly placemarking here

It's certainly one way to keep the kids entertained over the weekend I remember being taken to see the redcliffe caves in Bristol as a child, but I understand they're not currently open

Ooooo how exciting!!!
I’d be out there helping them!
Really don’t think they’re in any danger whilst it’s earth and stones.

If they make it to solid rock however, I think some caution would be wise!!

Please do keep us updated op...this is proper good!! —jealous—

The digging is taking place about 15 metres away from the house and they’ve had a look at where the water and gas pipes are. It’s not near any walls either so it hopefully won’t cause any structural issues.

From the map it looks as though the cave goes straight along from the house that it’s under but our house is up a hill about 20 metres higher than where the entrance is. I can’t imagine they’re going to dig much deeper before they hit rock and then they’ll (hopefully) give up.

meredint yes they’re trying to get into some caves that are already excavated. They were open as a tourist attraction years ago. There’s a door that used to be the entrance below someone’s house down the road (it looks like a coal hole type thing). The house is just a holiday home now though and no one is allowed in. Dh and friend want to excavate a new entrance in our garden and have their own private cave network for God knows what reason.

This sounds fucking stupid. Surely the network was closed for a reason.

This sounds amazing and I would be out there with them...how have you not done this before OP??

Put a stop to it. The chances of them falling into the cave are low, cave chimneys are usually fairly clear at least. But the chances of them having their hole collapse in on them if they get deep enough are much higher and it's not safe at all. My father was the chairman of the british cave rescue society so I grew up with a whole lot of this safety stuff :)

If they want to look in a cave they should go to a showcave that's still open :) If they want to explore a cave and look for fossils then they need to start reading and training and learning how to cave properly, it's not a risk-free hobby. People die doing it and some of those peoples' bodies can never be recovered. I get the joy, I loved caving in my younger days, but it needs education, training and proper safety procedures.

Grief.. Private cave network? Just how experienced is this caver friend?

Just waiting for a neighbour to think they are digging foundations for something and Building Control turning up on the doorstep.

If they plan to keep digging, are they going to shore up the sides of their trench? If not, I'd guess they are digging their own grave.

It’s like an Enid Blyton - the Famous Five Go Caving (although there’s six of them)

it hopefully won’t cause any structural issues.

I was going to say that I hope you have a spare home, but I see this is the spare home, which I guess explains your relaxed attitude to all of this, OP!

This network of caves is closed so presumably no-one is monitoring its safety for people being in there - I certainly wouldn't be happy with my DC running around in a disused cave network- what if they don't come home for tea one day?

It sounds like a cool idea to a child, but someone in the family has to be the voice of reason, surely? Otherwise you'd have kids camping out on rooftops because they can access them from skylights and taking dinghies on the weir. These are all things that are cool in theory but bloody dangerous in reality.