I'm currently remodeling a 13'x16' master bedroom floor. The house was built in 1988. The bedroom was originally carpeted, but I'm changing it over to sheet vinyl. I took up the old carpet and found the underlayment to be 5/8" particle board. I decided to replace it with 19/32" B/C plywood prior to putting down the vinyl. This would have matched the height of the adjoining bath floor, which is also vinyl. I took the particle board up and found the subflooring to be 15/32" OSB, non tongue-and-groove (lots of give along the long edges). At this point, I'm seeking advice on options to proceed with correct materials/thicknesses and do it the right way this time.