On top of the
OSB, we lay 3/8 plywood.
Our subfloor is now over 1 inch high. (This was not planned, the floor
nailer didn't have shorter nails, so we ended up doing the floor twice)
 The plywood is attached to the OSB with rust-proof screws |
 The entire subfloor is attached to the concrete with Tap-cons. We then seal all drill holes and seams with caulk. |