Sub Floor Replacement

cs2kplus wrote:
@westend...ah..yeah that sounds better. The problem with 3/16 (which I have seen) is that I am joining to existing front floor (which is fine). So the stackup height needs to remain the same. Unless - the is stuff you speak of can be compressed to 1/8?
@Teachers Pet....see above.

I was wondering if this would be ok?

http://www.homedepot.com/p/Unbranded-1-8-in-4-ft-x-8-ft-Tempered-Hardboard-832777/202046928?N=5yc1vZbqm7Z1z0z6jh

No, Lauan won't compress. Since you are starting from the bottom and working up, I would get a sample of each piece of the flooring puzzle and see how they stack to your existing floor. Plywood, nominal 1/2", is not. It's typically 15/32". Another thing you can do is where the new floor meets the part you are keeping is to screed a filler along that seam. If the new floor is within an 1/8" or 1/16" of the old, a feathered seam will make the transition invisible. Actually, when I install vinyl, I fill all of the seams, knots, holes, etc. with a light filler, anyway. I don't want anything to telegraph through the vinyl. If you are overlaying with laminated flooring or carpet, this is all a non-issue.