Can you put concrete slabs in concrete base?

[lms78]

Hi,

Can you put concrete slabs into a concrete base?

I plan to put in a 5m by 3m summer house and an 8ft by 6ft shed in next year. I have loads of slabs from old patio and paths.

I have kept hold of them in case they can be recycled in this way, but my local council are about to start charging £4 per slab taken to the tip. This is the last weekend I can get rid of them for free.

Should I keep them? I assume if I can use them, it will actually save me money, as I'd need less concrete mix when creating the base?

I assume I can only use one layer of them, or could I even get away with two layers (i.e. one slab on top of the other?)

In addition to having square and rectangular slabs, I also have some hexagonal ones. I assume they will be more hassle than they are worth for this use?

Thanks in advance for any advice.

 

[John D v2.0]

In general you need to have a good mix of sizes of aggregate to avoid having any voids that could collapse or gradually fill with whatever's underneath when it gets wet and sink. However for a shed you're not holding up a 3 storey house.

 

[r896neo]

Break the up and throw them in. As long as your concrete remains at least 75-100mm thick.

Otherwise pour your concrete low and you the flags as your finished surface.

 

[lms78]

Thanks both for your replies.