More crush or grit sand

All forms of block paving, brick paving, flexible or rigid, concrete or clays, new construction or renovation
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nqtraderman
Posts: 1
Joined: Sat Feb 29, 2020 9:19 am
Location: North West

Post: # 118226Post nqtraderman

Hi, I've had the driveway (120 m2) dug out and stoned up but the lad with the mini digger dug a bit too much out. It's had 21 ton crush so far and wacked and is about 100mm deep and it's between 100 - 120mm down from finished level. I'm going to be laying 50mm Tegulas so that leaves me needing between 50 - 70mm for the grit sand.

Is that too deep for grit sand ?

I could either top it with 30/40mm more Crush and then 30mm grit sand or just make it all up in grit sand.

Either way the cost per loose ton is the same, except that it will be easier to shift (and level) grit sand than stone as the digger lad has been paid & gone so it's all manual shifting now, and it's a big area, 120 m2

If I go with all grit Sand I can get 20 ton in one drop, level & wack it, in stages, ready for the blocks, as opposed to paying for a smaller amount of crush, wack it and then grit sand to be dropped off separately. But then I'm into minimum quantities per load which I think is 10 ton.

Whichever route I go it's going to be thoroughly wacked down and the edges are all in place and solid so nothing can move laterally.

My question is this, from a structural point of view, is there any difference laying the Tegula block paving on 30mm, 50mm or 70mm wacked grit sand as long as there's sufficient wacked hardcore underneath it or does more sand potentially cause sinkage even though it's wacked hard ?

thanks

KAMIKAZEE DIY
Posts: 139
Joined: Thu Feb 27, 2014 8:45 pm
Location: Scotland

Post: # 118227Post KAMIKAZEE DIY

Type 1 or crusher run would have a higher load bearing capacity than grit sand. If possible calculate how much type 1 or crusher run you need and get it delivered in bulk bags. When it gets delivered (if possible) get bulk bags evenly placed out so you can slit bags and then move it around as needed. That way it might cost a bit more than a loose delivery but you won't be moving it the length of the driveway.

Hope this helps.
Cheers

Tony McC
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Location: Warrington, People's Republic of South Lancashire
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Post: # 118235Post Tony McC

Yep - top-up with DTp1 rather than use overly-deep sand.

On 80+% of jobs where I investigate undulations and channelisation, I find the laying course sand is far too 'generous'. From the 70s to the late 90s we used tos spec 35-50mm of laying course sand, but since the turn of the century, we've relaised that the sand is often the 'weak link' in the chain, so the standard spec nowadays is 25-40mm.
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jwill
Posts: 148
Joined: Mon Feb 08, 2016 6:00 pm
Location: leic

Post: # 118240Post jwill

Stone is pretty easy to move about. If the tipper driver is any good he can spread it if can get onto your drive. Or slit bags as above

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