Planning to build a 10 X 12 shed. Wood straight onto concrete, or raise slightly?

[big-all]

wacked MOT and then concrete lintels laid over at 90 degrees to the bearers. This is what my shed supplier recommended a few years ago (they supplied and installed). No need for a concrete pad for a shed they said. They were right - it's been fine.

mines is on bare clay soil lump hammer lots off bashing to firm up the ground slab/part slab/brick/slate handfulls off sand what ever to give height needed on a gentle slope topped with felt or dpm then 3x2 treated joists in a 600mm grid pattern and 19 years on all fine