Aggregate calculations - How much to buy?

Foul and surface water, private drains and public sewers, land drains and soakaways, filter drains and any other ways of getting rid of water.
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Whitepj
Posts: 8
Joined: Wed Sep 07, 2016 10:13 am
Location: North Shropshire

Post: # 113776Post Whitepj

Really sorry guys - this is probably a FAQ. It also have been answered somewhere else, but I haven't seen it...

Regarding "french" drains: I have my trench all ready. Basic maths gives me the volume of aggregate required to fill the hole, and the specific page on these things tells me I need to order Type B aggregate...

But the supplier sells in bulk '1 ton' bags. How do I work out how much I need to order, based upon the volume of the hole I've dug?

??? Thanks.
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seanandruby
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Joined: Mon Jun 26, 2006 11:01 am
Location: eastbourne

Post: # 113781Post seanandruby

here
They are not 1 ton bags they are bulk bags.
sean
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Whitepj
Posts: 8
Joined: Wed Sep 07, 2016 10:13 am
Location: North Shropshire

Post: # 113784Post Whitepj

Hi Sean,

OK. I'm being thick.
I can find calculators for mixing concrete, calculating bedding mix, sub-base coverage and grit sand volume.
Can't see what i need to work out what I want (bearing in mind that a big proportion of the drainage is going to be voids)

Sorry...
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digerjones
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Joined: Fri Jan 18, 2008 9:32 pm
Location: cheshire

Post: # 113785Post digerjones

As I see it if you're trench calculation works out you need 1 m3 of gravel then that would be about 1 dumpy bag
dylan
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Tony McC
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Post: # 113830Post Tony McC

Type B is (very roughly) 1.9T/m³ - there is quite a bit of variation from aggregate to aggregate, but that value is a reasonable 'average'.

So, if you know the volume rquired, multiply by 1.9 for the tonnage. The Bulk Bags supplied by Builders' Merchants are allegedly, about 850kg, but some are as much as 100kg less than that so chjeck before ordering.
Site Agent - Pavingexpert
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