Patio Sub Base/Rubble Question

[mjjm986]

Hi everone, I'm looking orf some advice on a patio project.

I am paving an area 5m x 3m. The ground is unlevel at different points and needs raised to be level with the pathway.

I have excavated loose soil and have a depth of 8 to 10 inches to fill.

I have laid a layer of stone chippings around the edges and compacted it. I'm going to put a row of 6 inch building blockes around the edges, just to help retain everything as there are different levels along the perimiter.

The building blocks will allow me to compact the area and then infill the outer edges with soil when levelling the lawn area.

It will leave me with 8 inches to infill before I begin paving.

I have decorative gravel I want to clear from an area and also sizeable chunks of concrete from an old concrete path.

Can I use the concrete and decorative gravel for part of the subbase and then add some compacted gravel on top?

 

[foxhole]

As long as you break up the concrete, needs to be no bigger than a golf ball or you may end up with lots of voids in the base .

 

[mjjm986]

Thanks Foxhole.

The pieces I was going to use are from an old pathway. What if I used the bigger pieces, approx 30cm x 30cm by 10 cm deep. I was thinking I could lay the flat side down on a compacted layer of stone chippings (the ones with dust in them). Then fill between the concrete with the old decorative gravel I'm lifting. Then finish off the with remainder of the stone chippings.

I'm hoping this will help minimise voids and save cost on having to pay to have old concrete taken away.

Would this work?

 

[mjjm986]

So, I decided not to use the concrete. Instead I used the old decorative gravel to fill half and quarry chippings to fill the rest, using a compactor as I went, compacting every 3 inches or so. I used 6inch block round the edges to keep everything in as the levels are.lowe on the outside edges in places. Should give me a good sold base for the patio. Just need to get the manhole built up, I didn't even know it was there until I started digging.