the best underlayment for vinyl tile
I am about to install vinyl tile in my old kitchen. The subfloor is half hardwood tongue-and-groove plank, and the other half really old looking plywood. I think what previous owners did was to take in the porch, thus the different subfloors.
The floor is quite sturdy and pretty much level, maybe a 1/16"-1/8" difference in the two subfloors. I have completely removed the old linoleum.
My question is what underlayment to use? Would 1/4" or 11/32" b-c plywood be adequate, in terms of smoothness and sturdiness? I live in a rural area and not much else to choose from. The guy at Home Depot suggested 1/2" OSB, but I am a little leery of OSB for vinyl tile.
Thanks in advance for advice.