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aemeijers

wrote:
going to use 10 treated 4x6 posts as foundation for 10x12 shed.....guy at
menards sugested coating with tar to extend life. sounded like good idea to
me...also building inspector guy advised me not to concrete posts in ground
or frost will be problem.....dig holes 48" then concrete in bottom of hole
and posts sit on the concrete....sound OK? Thanks

It is a little more concrete to mix, but correct answer is to pour
rebarred concrete piers (probably using the cardboard Sonotube forms),
and drop a big J-bolt in the top to anchor a metal standoff plate from
Simpson or similar. You then put the 4x6 posts in the standoff plates.
Once shed is framed and squared up, you lag the posts in place through
the holes on the standoff plates. If the piers are down into undisturbed
soil, they should last essentially forever, and your timbers will
probably never rot. Piers don't have to be tall- just want them higher
than the rain splash/snow line, and tall enough to make it obvious if
any termites start building tunnels up to the wood.

If that sounds like too much work or bother, just put gravel in the
bottom of the hole, set and square the the posts, fill the sides with
tamped gravel, and maybe put a small concrete cone on top to shed rain.
Idea is never to trap wood in a concrete pocket- always give the water
someplace to go. IMHO, tar will do more harm than good, and tend to keep
the wood wet.

And unless you have strange local conditions, inspector guy sounds
clueless- if the hole is below frostline and into undisturbed soil, and
properly sized, frost heave shouldn't be a problem. Maybe he meant to
not put a big concrete mushroom on top at dirt level- that can heave
enough to yank even a deep post out of position.

--
aem sends....