i live south of houston alot of moisture and mold i plan on using the titanium roof wrap my question is can i put it directly on the decking then put 2x4 every 4 ft then 2 layers of 3/4 foam board between the 2x4 then put the wrap on top of this then the metal or leave 1 layer of wrap off to prevent mildew which is best place to install wrap thanks for your avice jim