"Andrew V" wrote in message
...
WOW,

Gentlemen thank you for some great responses, lots of useful info. I
spoke
to a contractor today and he suggested a combination of tube deep in the
slab and some separately poured spots for the power hammer & shear.
nothing
else will really need to be anchored deeper then 4"

A couple of follow ups:

Harold-- is the rebar @ 18" centers in addition to mesh or instead of?

Instead of. However, if I said it was on 18" spacing, I was wrong. The
hoses are, but the rebar is on 12" spacing. I have a photo of the layout in
one of our albums which I could scan if you're interested. It worked out by
choosing where I tied the hoses. I could install rebar as cheaply as mesh
at the time, and I don't like wrestling with the mesh that comes from rolls.
It's clearly a bitch to get flat enough to keep your hoses where you want
them, and dobies don't do much of a job of keeping it at the right height.
I decided that if I was going to spend the money, I may as well get the
benefit of the stronger support. No regrets, aside from it taking a lot of
time to tie the intersections. I poured about 2,600 square feet. I
strongly recommend the rebar in lieu of mesh to avoid any settling should
you get cracks.

I added a lot more rebar at the entrances, where I risked breaking the edge
of the floor with my lift truck. It weights about 5 tons alone, as I
stated, and I figured it was cheaper to add rebar than to fix a broken floor
and heating system. To that end, I ran additional rebar from the entrance
to roughly 6 feet in. That maybe wasn't necessary, but the floor hasn't
cracked, in spite of having hauled a maximum load through the doors, so I'm
happy I made that decision. I also used a 6 sack mix. In my opinion,
saving a couple hundred dollars on a project of that magnitude is not worth
the risk from cutting corners.

One other thing I did was install a built in vacuum cleaner, a large one
capable of servicing 18,000 square feet. All of the pipe is either under
the floor or poured in the walls. Twin motors, with no filter bag. It
discharges directly outside and has a cyclonic separator. We'll extend it
to the house, so it will serve double duty. If your budget can stand the
cost, it's a super way to go for keeping a shop clean. We can walk around
in stocking feet with no worries (we're living in the shop while we build).

Good luck!

Harold