Originally Posted by Wabbiteer
You won't put a 1" air gap between the floor and frame; the original compressed fiberglass ended up about 3/16" thick so thats a good measure to try and duplicate after the floor bolts get tourqed down. I arbitraily made the 1/4" thickness for air-gap space but doubled that in the centers of floor area as seen from beneath so any liquid water will drain to the center and out through the staple holes. If & when the shell comes off everything I've done most likely will get discarded but a 1/4" frame-floor gap will line up with what has already been done.
My floor did not have fiberglass batting underneath it. The PO opted for a thick spray foam that expanded to the full area size. I may misunderstand what you put, but do you mean that there was fiberglass between the frame metal and the subfloor?