"Phil Anderson" wrote in message
...
Good Morning, All,

I have an elevated deck over my carport. The kitchen door and bedroom
door
open onto the deck and we have patio furniture there for meals and
gatherings. Because the deck is over the carport, it has to be
waterproof.
I also barbecue on the carport because with the protection of the deck, I
can do it year 'round.

Probably not what you want to hear, but I would replace the rotting plywood,
have a roofing company put a rubber membrane over it, then put a "floating"
deck laid on the rubber. You could use 1X4 green lumber, with the decking of
your choice nailed to it. Build it in sections so you can remove the decking
to clean under it a couple times a year.
Greg