On Thu, 22 Apr 2010 13:59:48 -0400, "Don Phillipson"
wrote:

"terry" wrote in message
...

All previous outside structures have built, three sheds one cabin,
large wooden deck etc. we have dug down and used posts (stubs of
telephone poles and similar.

Now wondering if possible to build a shed on those concrete blocks
that just about sit on the surface. The blocks probably weigh 50 lbs
each, and are shaped on top to fit four by four post or cross member.

They are sometimes used here to support a deck or patio.

If the local building code permits this for uninhabited structures
the municipal building permits office will tell you. (You need to
know whether such a building requires a permit because, if you
decide to build without one, you may need also to camouflage
it somewhat . . . ) Just here, on top of an esker (sandhill) decks
on surface blocks seem equally as stable as those on concrete
pillars (sonotubes) sunk below the frost line.

I (re)built the deck on my previous house ten years or so ago and used
sonotubes. Every year the frost got to them and pushed them out 3-6",
sometimes more. Every year I had to relevel the deck and every other year I
had to rent a concrete saw to cut off the pillar. When they finally came out
(all 4') I put the deck on blocks (made for the purpose) and never had another
problem with it. It would go up in the winter and go right back in the
spring. I built it completely free-standing so this didn't cause any other
problems.