The floor of my bathroom, on the third floor of a coop building built in 1945, is not level. My licensed contractor removed the original cement floor and installed new 3/4 plywood on top of the floor joists. The difference in height from the exterior wall (highest point) to the entrance door (lowest point) is 1.5" over a distance of 65 inches. He added wood to the floor joists so the new plywood sub floor would be above the metal straps holding the original floor joists (where they intersect at 90 degrees). As a result, the new sub floor is now level with the hardwood floor in my hall way. All the tile installers are telling me he should have leveled the joists before installing the new plywood, and the subfloor should be lower. As a result, I am going to have a 2 inch high step at the entrance to my bathroom after they install the new tile floor. The tile installers are recommending I remove the new tub (installed by a licensed plumber) and re-install the plywood to reduce the height and make it level before the tile is installed. Is that the best way? My contractor insists that installing new tile over an uneven floor is okay because he would level it with the thinset. What should I do?