First Floor insulation was completed yesterday. We used an open cell soybean oil based foam insulation with an R-value of 13 @ 3.5" THK. The radiant floor requires R- Values 21~24 for maximum performance. The minimum specified for our project is R-19 per code; we will achieve R-26~30. It was essential to have the height clearance  be 24" +/- at crawlspace; it is easier to navigate under the house.