What flooring system do you all suggest between daylight basement & main floor? We're wanting to do radiant heat & valance cooling with geothermal closed loop system. Looking at PolySteel & Quadlock ICF's (local to zip 28018) Engineer who's working on plans says very expensive to engineer plans wf poured concrete floor, we're wanting basement to have wide open space, right now basement @ 2250 SF, going to use 1/3 of that for HVAC & shop room, want to leave rest of that as open as possible.
Current basement dimensions @ 61' wide by 53' deep, so that's like a 40' span max in basement area, I guess no matter which way we'd go, we'd have to have a post or two...

WE use a product for concrete floors and radiant heat all the time called SpeedFloor. Works great for us as we don't need a crane to set the joists. Man power only. You would need a beam down the middle for best results. We set 3,000 sq. ft. of joists yesterday with 6 men in one half a day. Would have been quicker but we had to cut aver half the joists off 2". Tt will require welded wire and 4" of concrete. If radiant is used it is quiped to the wire. Quick and simple.