After investigating various ways of building a base for a garden shed on
sloping ground I've bult a wooden frame out of treated 2x3 and plan to
drop 6 uprights into holes that will be filled with postcrete. Initially
I was going to make the uprights by cutting stub concrete posts in half
but am too concerned about the steel rebar (spalling and drilling holes)
so then decided to use treated 4x4 and accept that they will rot over
some years. Now I'm wondering about cutting strips from thick
(non-reinforced) concrete slabs and using those on end - they should be
OK to drill and there won't be significant sideloads.

Any comments?