So at this stage of my renovation, I am floating on air... well, suspended on a couple of 40 year old pieces of lumber. It wouldn't have been so bad had it not been for the fact that it was 3/8" plywood, partially rotted through, on 24" joists! The 2x4s you see on the left are for cutting up for some additional horizontal supports between the floor joists, to further reduce the bending of the plywood as we step on it. Any bowing of the flooring will result in cracked tiling, so I want to reduce it as much...