Mark Benjamin of Crown Jade Engineering delivered the final plan for the Waffle Mat system just was the plastic vapor barrier was being installed. The plan is engineered with the PSI concrete standards using a PSI computer program that took some time to receive and install. Mark called in Lisa Farmer, another PE, to help with the software and they both checked their design with Greg Carr, the Texas Wafflemat sales engineer. The floor calls for a double row of 5/8″ rebar in the 8 1/2 inch beams below the slab (actually calculated as 12 1/2 inch including the slab) and 1/2″ rebar in the slab at about 9.6″ on center. Which works out to two bars over each box and a bar between each box. It seems this is going to be a rigid slab construction!
This detail shows the box, the 2″ of insulation over and between the boxes, and the rebar placement. The building inspector asked for a bit more detail so the areas in “clouds” were added to the original drawing.
And here is how it looks as the boxes are being installed onsite!