Garden path & shed base using a dry mix

We want to lay a concrete shed base and extend it into a bit of a path. It would end up approx. flag shaped i.e. a rectangle with a longer thinner section coming off as the path. A friend suggested making a wooden frame, filling with some kind of dry mix, levelling & compacting then spraying with water. Something he had done in his garden.
Can any one help fill in the fine details?
Would I need a hardcore base - if so, what depth? or
Would sand be OK as the base - if so, what depth?
What depth of dry mix would I need to allow for?
Can you buy pre-mixed dry mix or what do I mix together?
How do you work out how much of everything to buy?
If I know depths I can work out the volumes of things, but sand & cement come in kilos/tonnes not cubic metres!
Any other advice welcome!
OonaghG

Hi, oonagh
The preparation depends on the state of the ground/subsoil etc.
But as a general rule, if you dig down 8" and put in some small hardcore to about 4" below finish level and compact it, and then set up a framework of timber to the finished level, Put in drymix to 1 1/2" below finish (using notched timber to tamp off the frame).
Lay the slabs on to a line set off the framework and bed them as you go.
there is no need to wet the dry sand/cement mix as the natural dampness/rain will set it.
Point in the next day and point up with a bucket handle tool.
don't be tempted to brush in as that will only make a mess.
The quants can be calculated easily as a ton of sand measures 2.2 m2

That might be a mt2 = 2 tons of sand.
ask noseall he'll know for sure.

Wasn't planning on laying slabs, just the concrete!
What items do you mix & in what ratio for the dry mix? Does the m2 to tonnes work the same for plain sand & the mixed stuff?
OonaghG

Oh, sorry,
just a concrete base then,
Ok
Similar substrate of compacted hardcore, (broken bricks or type 1, chalk or concrete bits.) similar depth.
Just mix the concrete or order ready mix .
Concrete is 10-1 balast to dust.
order 2 ton of balast and 8 bags of dust.