Q: What is the wax paper for and is it necessary for installing 3/4 ” thick hardwood? I’ve heard some people use the felt paper, any comments?
Also, do you need to lay the plywood over newer homes 5/8″ O.S.B.if it’s fairly level?
A: The wax paper simply makes moving the boards in to place easier. No, it is not necessary but makes the job easier. Tar backed paper can slow the transfer of moisture from below, but if you have such a high moisture level in your basement, the you really need a dehumidifier.
I do believe that manufacturers now accept OSB provided it is of a minimal thickness for any given floor type. check NWFA site for the exact measurement. but to be sure, it will be 3/4″ or thicker.