I plan on laying tile in an upstairs bathroom. I am going with 3/8″ x 16″ on the floor. Do I need to lay a mud floor for this size tile? Also I am ripping up the old mud floor and tile and am planning to put a new subfloor down. Should I try to go over the old wood subfloor once the old tile and mud is ripped out or should I just take everything out and put down a new subfloor? I also have a couple of questions regarding the subfloor. (1) What should I use for the subfloor? (2) How should I go about taking out the old subfloor where it runs under the sole plates? Should I just cut it short of the walls and then piece it in? I would really appreciate some help, Thanks guys.