"SteveF" wrote in message
...
Thanks for the info.

One question comes to mind. One my first (and only garage) I did a 6"
concrete floor with fiber reinforcement. No rebar and no mesh. Cut
control
joints properly. A year later no cracks except the ones in the control
joints and everything looks fine.

If I put in radiant piping I must but in either mesh or rebar to hold the
piping in place during the pour. From what I've read on the concrete web
sites, the rebar shouldn't cross the control joints since that defeats the
purpose of the control joint. I guess the radiant piping can stretch a
little without a problem.

How did you handle the control joints or did you just leave them out?

Thanks.
Steve.

The guy that did our floor does a lot of commercial concrete work and
suggested that he score the floor with a bull float with a skeg, for lack of
better definition, then finish over the score. He said any cracking would
follow the score, even though it wasn't visible. His rational is that the
skeg separates the coarse aggregate, which is expected to lend the greatest
strength to the concrete, and replaces it with fines of lower strength,
encouraging the floor to crack at specific places. It turned out exactly
that way, in spite of the fact that our rebar is continuous. Any cracks
that have occurred are at scores, although not every score has cracked. We
haven't found any wild cracks, and the floor is now 5 years old.
Therefore I'd have to say that the information that suggests rebar defeats
the purpose of the score isn't true, at least in our case. To be perfectly
honest, there's no way in hell I'd pay the price of hydronic heating and
install it without something to prevent the 'crete from moving when it
cracks, and crack it will.

Regards the piping-------I know I'll sound like an idiot, but I don't have a
lot of faith in the plastic stuff. We used rubber hose, a product made by
Goodyear to Heatway's specifications for the purpose of hydronic heating.
I figure it will tolerate a little misalignment, but at this point that's a
non-issue. I'm sure the plastic would have worked equally as well, and it's
one hell of a lot cheaper to buy. We paid roughly 70¢/ft. for the 3/8"
rubber hose. While we didn't pay for a trace, they make the same product
with a trace so it can be detected easily. I felt no need because it's
placed deep enough.

Harold