Vapor barrier in porch floor with mineral wool insulation
I have a screened porch with an exposed wood floor (8′ above ground) that I have started to transform into a 3 season porch (location: New Jersey ). Tilt windows were first installed to replace the original screens. Original floor is 1×6 pressure treated boards (with small space between boards to let air through) on 2×12 joists. I started by installing rockwool comfortbatt (R23 – for 2X6) between the joists and covering underneath with painted and caulked SmartSide 38 panels. On the interior side, I am planning to cover the 1×6 boards with RevolutionPly plywood and install on top of the plywood laminate flooring (Pergo Outlast+) . I understand I need a vapor barrier underlayment between the plywood and the laminate floor. Should I also consider CertainTeed MemBrain in case there is a different flow of humidity between winter and summer? Should I also assume I do not need a vapor barrier between the 1″x 6″ boards and the plywood?