How to get concrete out of the ground

Roger465 · 4 Jul 2019

Sorry, not a great pic – the centre of the grey mass is a very solid lump of concrete, a foot to 18 inches across, with a bit of scaffold stuck in the middle. It is completely immovable, so I assume it goes fairly deep… it used to from part of a 2’ square base for one of those rotating washing lines.

I want to remove it, and foolishly thought I could just smash it into bits with a sledge, then dig it out with a pick – but, having broken off the original 2’ square top, and battered away at what’s left for days, I’m not really getting anywhere.

Anybody have any great ideas for demolishing it? Or how far down it’s likely to go?

Thanks all

JohnD · 4 Jul 2019

hoist it out with a jack if you can get one. Once it has moved a bit, the rest is easy.

Or you could hire or borrow an SDS+ drill. heavy but it will slice through the concrete, with a chisel bit, set to hammer but not rotate. You can buy one for £60 upwards.

old concrete buried in the ground is particularly strong and hard, because years of damp improve the cement. Being damp also makes it harder for you to lift. In one piece you would hard to lift even if you dug all round it.

Munroast · 4 Jul 2019

dig down the side of it, find out how far down it goes. Once you get down to the same depth you maybe able to prise it over into the hole you have dug, once its loose you should get some idea if it is possible to lever it out. Don't try and do it all in one go or you may bugger yourself.

conny · 5 Jul 2019

Fit a 12" (300mm) masonry bit, 8-10mm, into your drill and drill a test hole about 2" from the edge. When it goes through the bottom it will plunge down easily. The dust marks on the drill will give an idea how deep it is. Then do another hole near the centre to see if it's the same depth or a bit deeper. It may be conical shaped underneath where the original hole was dug out.

bernardgreen · 5 Jul 2019

This might work for your lump of concrete

One hole and a large expanding bolt to fit.
Lift the end of the beam to lift the concrete a couple of inches.
Wedge the concrete to stop it dropping back.
Lower the beam and add more height to the spreader block and lift the concrete a few more inches

Repeat until the concrete is high enough to be moved away from the hole,

Roger465 · 5 Jul 2019

Just a quick thanks to everybody who's contributed so far - I am reading them all as they come in, and will have a go at something over the weekend.

Please keep your ideas coming

Burnerman · 5 Jul 2019

Hire an SDS drill with a nice big bit, say 20mm. Drill a couple of deep holes, shove a large cold chisel down and beat merry hell out of it.....it will split readily enough.
John

Munroast · 5 Jul 2019

Burnerman said:
Hire an SDS drill with a nice big bit, say 20mm. Drill a couple of deep holes, shove a large cold chisel down and beat merry hell out of it.....it will split readily enough.
John

Either that or it will become like King Arthurs Sword

this actually happened to me, lol, I had to drill another hole and risk another chisel stuck out of the ground like Excalibur's long lost cousins - thankfully it did eventually split. it could have been very embarrassing

Roger465 · 5 Jul 2019

Munroist said:
Either that or it will become like King Arthurs Sword

this actually happened to me, lol, I had to drill another hole and risk another chisel stuck out of the ground like Excalibur's long lost cousins - thankfully it did eventually split. it could have been very embarrassing

This WILL happen to me, trust me - I know how my karma works.

I will end up with the thing bristling with chisels like the throne on Game of Thrones...

And I guess I'll have to hire meself a fancy SDS drill...

Roger465 · 6 Jul 2019

Hhmmm, major expense it seems, for just this one job... the ones for hire seem to be 110V, and by the time you hire a transformer, bits & everything, you've spent £¾M pounds...

Would this be any good?

Burnerman · 6 Jul 2019

It'll do what you need for this job without any problems.....its a bit on the heavy side for general SDS work like drilling for wall plugs or whatever. Heavy to hold, I mean!
John

Munroast · 6 Jul 2019

think I would just dig down the side of it first and try to work out how big it is. I wouldn't waste money buying or hiring a tool just for this. If its not that big you could dig it out and if it is huge then that little sds will be of no help.

What do you thing it was supporting, a childs swing, flagpole or something else. Can you not hammer a metal bar down the middle of the scaffold tube and use it as a lever?

Harry Bloomfield · 6 Jul 2019

Roger465 said:
Would this be any good?

That should do it, but you will need to source some long bits. I have a set of three extra long ones in my garage, about 3 foot long, bought as a Lidl special and so cheap, it would have been rude not to buy them. I have used them occasionally.

If nothing else, you could chisel the top away and maybe bury it where it is with that.

Nige F · 6 Jul 2019

bernardgreen said:
This might work for your lump of concrete

]

A good diagram from Bernard - I would suggest a jack by the arrow - and a sloping hole from the arrow to the bottom of the concrete block. Then as it's lifted you can wedge behind it and roll it up the slope.

Keithmac · 6 Jul 2019

If its an ex council house that will have been the old clothes line poll, I removed ours abd it was a fair lump of concrete!.

Had to remove a few concrete wire fence posts as well ans again they didn't scrimp on the concrete!.

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

How to get concrete out of the ground

Similar threads