[thehulk1978]

Is it a goord idea to waterproof the usb board before i vinyl it....i bathroom i have done i noticed mold when i had to replace a peel in stick area....i think it would be a good idea

[Bullmoose]

Hulk,
First of all, get rid of absolutely all mold and fix those leaks that caused the mold.
Next, OSB is not a good underlayment for damp locations. It swells and wicks moisture. I suggest you tear it out and use a good plywood specifically suited for use as underlay. Regular plywood has voids within the layers that can crush under the weight of a heel. Any good lumberyard should be able to provide the right material.
Lastly, make sure the underlay is secure and smooth. Vinyl doesn't hide flaws, it magnifys them.

[Floorwizard]

agreed.

[R&D Tile]

Vinyl in a bathroom is a very bad idea, TILE it.