Yes, a 4" change in height from the old floor to new. We had 9 1/2 foot ceilings so this was not an issue. I don't have a cross section pic, but we did take s lot of video during the retrofit net zero build.
The install was simple. 2" EPS was laid down, followed by foil backed bubble insulation, 8"x8" steel mesh, and the PEX held in place with plastic clips that were pushed into the foam. 2" of concrete was added after.
In our loading bay, we cut out the 2" EPS foam out where the pallet rack feet were to be bolted down, and left these patches free if PEX as well. So in these few areas there was 4" of concrete.
Things we would do differently:
1. Eliminate the bubble insulation. It's likely a waste of money, and much of it was damaged by walking on it during the install.
2. Forget trying to pigment the concrete...light grey. That was a fail, and we had to do an EpoxyShield epoxy coat (the solvent based 75% solids stuff) for the 4800 sq/ft slab. We could have used a white mix like the sidewalks use here, and just polished it after.
It's been four yrs since, with heavy use including moving pallets, pallet jacks etc. and a few weeks with some very heavy hydraulic carts/lifts used in construction. Zero issues.
In terms of the radiant, it's a good choice for the loading bay zone, however given that we had to install air handlers for AC and fresh air, not sure I would spend the money on radiant just for heating. As it is, the floor is there as a thermal mass for the next phase adding solar water heating and PV panels to take us net zero.
