Thanks! Next question. The 3/8" subfloor that I mentioned goes under the wall plates. On one side of the room, the joist is located back under the wall plate. The next joist out is about 14"- 15" OC. But, from the edge of the bottom wall plate to the joist (the area where the 3/4" plywood would sit) is only about a 10" - 11" span. Is there any concern when I glue and screw in the 3/4" plywood since I won't be hitting a joist along this edge of the wall? I can't add any cross bracing, etc in this joist bay because ductwork is running in it. If I glue and screw directly into the 3/8" plywood, does this give sufficient support? The 3/8" is pretty solid in this area.
The plan is to glue and screw 3/4" plywood on top of the 3/8" plywood floor that runs under the walls. On top of this to add 1/4" cement board for tile. The powder room is about 4-1/2' x 5-1/2' in size. Goofy size. I cross braced in most places (especially under the toilet) to help solidify the floor, but my concern is a lack of a joist to screw the edge of the 3/4" plywood along the wall as mentioned above.