I am wondering how others have covered their decks to provide a dry area underneath. I have built a deck structure 16' x 32' attached to 2nd floor level of the house by a 2" x 10" ledger board bolted. House siding is Hardiboard cement board so flashing will have to be caulked/fastened to outside surface of siding. Have approved building permit and design meets FL Building code. Deck area is joists on 16" centers covered with 5/8" OSB which is covered with waterproof leak barrier material (GAF Weather Watch Grandular Mineral Surfaced Leak Barrier). I have enough 12" x 16' PVC hollow core deck boards (manufacturer u/k-see atch photo) and stainless screws to cover the deck but have reservations about water getting under the deck boards and causing problems, ie. mold, etc, and expansion problems. I am thinking of using grooved 2" x 6" PT boards around the perimeter to cover the hollow core (to keep out pests). Location is Florida coastal area. I would appreciate any comments, suggestions or criticism of this project.