slab over slab

kev

I know this is an old question but, 4" concrete slab with 2" of insulation both under and along edges. Now they want radiant heat. If we poor over this slab with a minimum thickness can I just figure the tube sizing, space,etc. as normal? I do not see any reason to isolate the slabs from each other. There is a limit as to how high the second slab can be raised, doors and such. Thanks for any help.

Alan(CaliforniaRadiant)Forbes

An old answer

If you don't isolate the slabs, you may get a flywheel effect. I wouldn't go any thicker than 6" total without separating the slabs or going with a "dry" method such as Thermalboard or Climate Panel.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

hr

Is it a basement

or slab on grade? In a basement I feel 1" would be plenty of insulation between the two, if this helps.

What's the final floor covering?

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Mark Eatherton1

One thing for sure...

the tubing will be in the "right" spot. I don't think I'd worry about another isolation shield.

Did ya ever notice in all the manufacturers drawings how they show the tube in the very center of the slab? Yeah, right... In your wildest dreams...

If you're in the upper part of the slab, it should work well.

ME

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"