How to build a roof properly in South Florida
I am building a new home in Naples Florida with a metal roof and open cell foam sprayed on underside of roof deck.
I am considering a peal and stick membrane under roof panels but have been advised I would be creating a 'double vapor barrier' potentially trapping moisture in the roof deck causing long term issues given Naples is hot and humid.
I was of impression open cell foam is an air barrier but not a vapor barrier, would the moisture only travel one way?
I have read one option is to a/c the attic space, another is to install the 'peel and stick' over old fashioned roof felt which seems like putting the new modern material over old technology material.
I am owner builder and will be installing roof myself, but spray foam of course by professionals.