The shed on is on the hill we made when we dug the pool out last year.
I am not planning to shot stars but did make the concrete deeper in the middle just in case. The C purlin only has rivets holding it so far, will update you when it all works. I put a piece of 4x1 across the back wall because it was weak after cutting the holes for the Cs. The shed is from RanBuild is 10'x10' and cost $840. Each wall came as one piece so it was easy to put up.
The boxing stays in place and is designed to keep vermin out, the walls sit in a L shape. See the slab here:
http://www.iceinspace.com.au/forum/a...8&d=1158872164