Using gravel to mix with hardcore aggregate?

mrcheez

I need 2.3 tonnes of hardcore for a DIY project but the supplier I'm using only sells them in bags of 1 tonne so I'd need 3 and then be left having to dispose of 700kg.

I do have an excess of 1/2" gravel that I ordered too much of though.

Is it possible to order 2 tonnes of hardcore and then mix in some gravel to bring it up to the required level?

Maybe the gravel needs to go on the bottom though it'll be hard to judge and I'd prefer to add it after finishing with the hardcore.

It's going to be a subbase for garden paving.

crashpilot

Realistically the bags will be shy of a tonne. Maybe 850 to 900kg.

So 850 x 3 = 2550. 3 bags might only just be enough! Maybe get 2 hardcore and a bag of sharp sand as well.

Had to lay my shed floor with half inch gravel and cement mix and the thing is absolutely solid, although the larger stones vibrated to the top and it looks like the surface of the moon.

Makes it an ideal surface for not slipping and not losing bolts and nails as they don't roll away, but wouldn't be flush enough to lay slabs over.

standardg60

https://www.boards.ie/discussion/comment/122683073#Comment_122683073

Agreed, if you need 2.3 tonnes in volume, ie 2.3 m cubed, then you'll likely need 3 bags. They don't contain a cubic metre.

mrcheez

What happens if I mix in quartz gravel?

mrcheez

I decided on 2 bags of hardcore as I need to use up the excess gravel I have.

I have a 1/3 tonne bag of hardcore to use up too.

I'm sure there's no issue using quartz to bulk up the hardcore if I put a mix in and whack it, then make sure the top layers are just hardcore

Also the tonne bag of sand i ordered will be over what i need so can fill it up as needed even over the required 4cm

standardg60

Whatever you do don't lay them on sand alone, lay them on a mix of mortar.

mrcheez

It's hardcore (mixed with quartz to bulk it up), then 4cm sand, then paving on top

looksee

standardg60 has given you good advice about the base/using sand.

mrcheez

Not clear what they were saying "lay them on mortar"...whats "them"?

The paving blocks sit on sand not mortar

looksee

'garden paving' suggests slabs, that's what I was visualising anyway.

mrcheez

Ah right, nah meant paving blocks

crashpilot

https://www.boards.ie/discussion/comment/122686405#Comment_122686405

I was thinking slabs as well 😄

mrcheez

Sorry assumed most diy paving was the one I was talking about 😀