On 30/04/14 15:10, John Rumm wrote:
For slabs used as a shed or greenhouse base, adding enough cement to the
sand to let it set a little once laid is usually all that's needed to
keep it in place. (used as a dry mix - no need to actually turn it into
mortar prior to laying)

About 30 years ago my dad and I put a new shed in the "woods" at the end
of our garden. Ground was rough as shite and not stable.

We levelled with a rake, dad made a boundary frame with some 3x1 (ish)
pegged at each corner.

We filled it with dry 6:1 sand:cement. Rammed down by hand, levelled and
slabs laid.

Gave it a good couple of hosings from the top then installed the shed.

Despite the frame being proud of the ground on 2 sides and the wooden
frame eventually rotting and falling off the slabs stayed put.

6:1 is weak but it's enough to hold the general shape.