I will strip the 3/4"tk x 3" wd t/g kitchen flooring and replace it with 3/4" t/g plywood. I will install solid vinyl planks (akin to laminate flooring) on top of the plywood. The question: Would painting the underside of the plywood serve as a vapor barrier to protect the plywood from absorbing moisture? It will be on above ground 24" center floor joists. The floor is approx 2' above ground level and sits on pillars.