Well, not technically a shed base but a Bike storage unit. This thing weighs 21 stone and requires a good solid base to go on (50mm thick slabs for bolting it down onto also).
The size of the base I'm laying is going to be 10ft (3048mm) by 3.9ft (600mm) and is going to be simple council concrete paving slabs (600x600x50mm)
As I understand, I need to dig out maybe 3" deep and lay a 8:1 ratio mix of Sand:Cement to about 2" deep, then lay the slabs on top and level with a rubber mallet.
My question is, how much sand and cement am I likely to need to fill in an area of 10ft (120") x 3ft 9" (47") x 3". I don't want to go and buy a shit load of sand/cement and end up with a shit load left...