Hi All - I opened up the interior of an exterior wall of our living room in our upstate NY post && beam 1850 farmhouse (8x13' wall). Outside is an uninsulated attached shed with an earth floor. The wall, from outside to in, is constructed of 1" plywood, thin (about 1 mm) foil faced styrofoam (perforated on one side, solid foil on other), tar-paper (about 1 mm thick), 1" board, rotting paper, 1" board with gaps between each board. The stud bays are ~8" deep. I'm thinking of putting R30 rock wool batts in, but I'm concerned about condensation. Would a vapor barrier on the inside of the rockwool prevent condensation? Should I consider rigid foam boards in each bay? The adjacent exterior wall (8x9') does not have an attached shed outside of it. This wall from outside to in contains vinyl siding, 1" extruded foam panel, wood lap siding on the studs, then the ~6" deep stud bay. Here I was planing on adding R23 rockwool. Do I also need a vapor barrier here? Any suggestions? Also, these are the only walls we're opening up at this time. Thanks for any help! Dave