Good evening, I have a layout question so I'll get to the point. I'm going to be laying down some 9/16 thick 4 3/4 wide engineered American cherry flooring on the second floor of my house. The subfloor is 5/8 t&g ply. Floor joists are 2x10's 16 inch off center. The problem I'm having is that on the second floor the joist direction changes in the master bedroom and runs parallel to the direction that the flooring in appearance should run. I verified this when I removed a couple areas of ply to shave down an upward crowned joist. So the predicament is should I change directions once I enter the master bedroom or just go against the normal schedule of perpendicular to joists? I could add another layer of ply but am hesitant to do so due to the height differential it would create. Thanks in advance for any help.

Hi Barron,
Since it's in the bedroom it shouldn't be a problem to run with the joists on the current ply, no need to add additional layer of ply or to change directions to go perpendicular to the joists. As long as your subfloor is flat it should go down well.
All the best.

with 3/4 wood I would agree, but with 9/16 I wouldn't just go over 5/8 plywood. I just don't think it will be solid enough. I also don't like American cherry for floors, it is to soft and being only 9/16 it will limit the refinishing capabilities.

Never a good idea to not follow NWFA or manufactures guidelines but to add the additional plywood called for and use a reducer in the doorway. Have seen it all from 3/4" x 2 1/4" nailed direct to floor joists, wrong size floor underlayment and while 10 times the amount I have seen not ok. Movement etc etc etc it always is a failure when I get called in to inspect.
As stated above you may have no problem BUT if you do you will know why.
Personally, I don't take those chances. Even when the clients home I have been in show that the installer did not follow guidelines if it has nothing to do with the concern I am there to inspect, as dictated the the NWFA standards for inspectors, I do not comment.