Do foundations require hardcore on base before concrete

[JoshRogan]

Hi all

looking at doing foundations for a garage and all the diagrams I have looked at seem to place concrete direct on the final dug surface (or at least thats the impression I got). Someone mentioned that it is best to put hardcore down before filling with concrete to prevent stress points.

Now I know this is the way when, say, laying concrete for a path or driveway, is it the same for strip foundations?

Cheers

C.

 

[rangersman]

Hi all

looking at doing foundations for a garage and all the diagrams I have looked at seem to place concrete direct on the final dug surface (or at least thats the impression I got). Someone mentioned that it is best to put hardcore down before filling with concrete to prevent stress points.

Now I know this is the way when, say, laying concrete for a path or driveway, is it the same for strip foundations?

Cheers

C.

Normally the concrete goes straight to undistrubed ground to minimise the risk of settlement. The only time I have seen anything go in before was in the form of a blinding layer (weak concrete) to create a firm, level surface for fixing reinforcement steel.

I would be surprised if your BCO would permit anything in there before the concrete, but maybe others have come across this before.

 

[cheltonian]

As long as the earth at the bottom of your trench is firm and compacted there is no need to hardcore it.

The BCO should inspect it before you pour any concrete, if you have building regs.

 

[JoshRogan]

Thats great guys, thanks for your input. I suspected it was not totally the done thing.

Building Regs not required, so it was worth asking the Q to get it right.

C.