Hi,

I'd like to add either a laminate or resilent fiber-glass vinyl floor on an enclosed porch in Maine. The flooring on the porch now is 5/4" pressure treated decking built over a concrete wall and floor crawl space. I was wondering what type of vapor barrier is need or necessary to add before I put down a 1/4" luan subfloor before I install the finished product. Should I put the vapor barrier over the pressure treated floor or on the bottom side of the floor joist.

Thanks