Floor forms in place

I’ve been out of town for two days, but was surprised to see all the floors w/ rebar in place.  Basically there is an 8” void under the basement concrete floor.  This is accomplished by laying void forms—like 8” tall cardboard boxes, along the dirt floor of the basement. Then they put OSB 4x8 sheets on top of those.  This just needs to be enough to support the concrete until it dries—it doesn’t provide any real strength.  There is a vapor barrier (plastic) on top of the wood so that will isolate all the organic material and any vapor below the concrete.   To keep things dry, mold free, and eliminate radon there is a series of perforated pipes all along the perimeter and down the middle which then come up and vent above the roof (a radon fan will be hooked up to this pipe and it will run all the time to keep fresh air flow).  Then there is rebar on top of that—it is epoxied into holes drilled along the wall-- and tied together with all the caissons that come up in the middle of the basement floor.  

They plan to pour the floor on Friday.  The radon vent pipe is located in the wrong spot so they will move that (someone had an old set of plans, I guess).  I also questioned whether we have or would need fresh air intakes (I think we would since the radon fan would otherwise create a vacuum). I’ll talk to Doug tomorrow on these items.