Ordering hardcore

[Dopeydaz]

Hi all, I have an area of 27m2 that I want to have a drive on. I want to have 200mm of hardcore after being compacted by a plate vibrator.

How much does hardcore compact? Should I order 27m2 by 300mm or even more? Thanks

Darren

 

[lasors]

For 200mm final compacted depth you will need approx. 11tonnes of type 1 MOT (crushed limestone).

Out of interest what is the reason for going so deep?

 

[Dopeydaz]

Sorry I have re read my post and can see the confusion. I need a finished level of 200mm. I was wondering if 300mm was about right as in spread it to 300 and compact it using a compactor. Would that finish to about 200?

The reason for going so deep is I'm putting hard core down, then gravel. I am going to be parking a fully ladened van or pickup truck on it. I don't want it sinking. 200mm was the amount I found on a post on this forum.

Thanks for your help, I'm a bit new to this!

 

[r896neo]

200 is a sensible depth for a heavy loaded driveway. Use the calculator below and it will give you the amount and factor in the compaction for you. It;s pretty accurate i have used it many times.

http://www.pavingexpert.com/calcall.htm#focus14

 

[lasors]

300 won't compact to 200, no. You'd buy hardcore by weight and not by calculated volume.

If your measurements are accurate, 11tonnes will do you. Presumably it's a driveway that you can tip directly onto, which is easier, but you shouldn't really try and compact more than 100mm at a time so maybe two deliveries would be better. If you buy it in bulk bags, cut them open on the crane and save shovelling.

For the gravel, consider using cellular paving. It adds strength and your gravel won't migrate all over the place every time you drive on it.

 

[Dopeydaz]

Thanks guys, I'll be able to get it ordered tomorrow now.

The new part of drive is off to the side of the existing drive but should be able to tip straight on to where it needs to go.

I'm buying loose as bagged I've been quoted £25 a bag. Loose direct from the quarry is £10 a tonne.

 

[r896neo]

what lasors says about compaction depth is important. You need to plate it in gradual lifts if possible.

i.e after 50mm again at 100 and again at 150 etc.

A heavy duty petrol plate will compact 100mm ok but you need to give it a good 10 passes or so.

 

[lasors]

Can I assume that you're putting 100mm of gravel down, if you were hoping to fill a 300mm hole and compact to 200? If so I'd say that was too much. Use a membrane to stop mixing of layers, use cellular paving filled with pea shingle at 40mm depth. I think cellular paving is laid on a thin bed of compacted sand, can't remember off the top of my head, but you can research that. It does help with stability but it will add to cost. Up to you of course. Have a look at it.

 

[Dopeydaz]

No sorry I shouldn't hav mentioned 300mm. The hole is 200 and I wasn't sure how deep to put the non compacted type one. As if I fill it to 200 then compact it, it would be less than 200mm. Sorry I wasn't very clear.