removing old foundations

[sm_jamieson]

I am digging the footings for my extension (it should have been the start of the summer !), and about 3 metres of the new foundation is in the same location as the old foundations. It turns out these are 3 brick courses down and concrete about 250mm deep 600 wide. Since they are half as deep down as the new ones, and only about 250mm thick, I am fairly sure the BCO will want them removed, rather than over- pouring etc. I dug out a small area in another location with my SDS drill, drilling holes though and then chiseling, but it was very hard going and I think I might need more heavy-duty tools to do this job. So, what tools should be used to break up and extract a concrete slab

3000 x 600 x 250mm ? Thanks, Simon.

[dom]

SDS Max breaker.

[John Rumm]

and a mini digger ;-)

[sm_jamieson]

How much more ferociously would you expect SDS max breaker to "break" than an normal SDS plus drill ? Would you just go at it from the middle, or have to chip off slivers as I did with my SDS ? Simon.

[sm_jamieson]

Hah ! I've started to digging by hand, and its not too bad. I guess the digger is to remove the concrete chunks. Simon.

[Lobster]

When I had to break up a slab with an ordinary SDS drill, I used it to sequentially bite off chunks... eg, imagining a line across a corner of the slab then digging in all along the line until it eventually cracked. My slab was probably only about 6" deep though.

I'm sure you'd find a bigger tool from a hire shop to be a helluva lot quicker though - that's certainly been my experience.

David

[nightjar]

You can get mini diggers with a power take-off to run a hand-held concrete breaker.

Colin Bignell

[The Natural Philosopher]

Mini digger.

Or bigger. About £100 a day or slightly more with a driver.

Dig down lever up and snap.

You will need a big skip or a dump truck, or somewhere to put the useful hardcore.