Tubing, Rebar, Ties and Backaches

Following the laying of the insulation, the next step was the rebar and the PEX tubing for radiant heat.

For the radiant system, I used LoopCAD to help me lay out the design for the tubing. With 1/2" PEX, about 1 foot of tubing is required per square foot of floorspace. Runs need to be under 300 feet. I did three runs of roughly 250 feet for the system, and didn't run it under the staircase to keep the design within the 750 feet I had to work with. 

I started with laying out the rebar at 32" on center. Final grid will be 16" on center, but PEX is sandwiched between layers.  

 Here's the tubing mostly laid out.

Final layout of the tubing and rebar. Aggravated the back after 500+ rebar ties and 700 or so zip ties on the tubing. Where the control joints will be, I wrapped the tubing with sill seal foam to protect the tubing from concrete movement. At the door openings I  filled in with leftover foxblock foam above the final height of the slab. After the slab has cured, I will trim the foam down to slab level. 

I put a tarp over the foundation to keep sunlight off the tubing until the slab is poured.