A crew of the concrete subcontractor’s men showed up this afternoon to lay down the rigid insulation on top of the washed rock. It was really quick going at first until they had to start doing the more detail work along the plumbing/diagonal area that rolls off towards the thickened edge. All in all I was happy with the quality of work although I think a table or skill saw would have done a much better job cutting even, straighter pieces for the transition to the thickened edge.
I took a few pictures while they were laying down the foam.
It’s pretty good… although not perfect. Guess that’s just the overly particular engineer in me!
After they were finished securing the foam they rolled out a 6 mm poly vapor barrier to go on top of the foam, between the foam and concrete. This should keep any moisture and harmful gases like radon out of the house.
As they were finishing laying the the last few pieces of foam it was obvious that they were running short and skimped on the detail in a few areas. I will definitely be talking to someone tomorrow about this rather large gap in the foam. This slab is supposed to be thermally isolated from the ground below, and a large area like this without insulation would create a HUGE heatsink.