I’m remodeling a soon to be rental property and I ran into a little dilemma with the flooring on a screened porch.  The screened porch appears to have once been a open porch with 5/4 PT decking that’s in fantastic shape when examined from dry enclosed storage area below the porch .  At some point the prior owner covered the decking with outdoor carpet (and of course, its glued down).  The gaps from the decking are telegraphing through the carpet and the carpet is faded and definitely seen better days.  We’ve been working on the house during some pretty horrendous rain storms and no water seems to enter the porch,  but I’m sure in the right conditions its going to see some water. One of my guys came up with the idea to cover the whole mess with 3/8 or 1/2 treated ply and then lay new carpet on top of it. His thinking is that the original outdoor carpet is inorganic so won’t rot even if sandwiched. Stupid idea or workable solution?  Or do I just bite the bullet, pop a few advil and spend some serious time with a floor scraper then call my chiropractor the next morning?