I live in Central North Carolina in a condominium community (formerly an apartment community) that was built in the mid-1970's. My unit is on the upper level and is partially separated from the neighboring unit by a 12-inch thick, brick firewall. The units are off-set, so approximately 40% of the wall is an exterior wall. This wall has no insulation and is framed simply with 2 x 6's and sheet rock. I originally planned to seal the brick and to use fiberglass batt and a vapor barrier to insulate the wall, but I've read that solid foam may prove to be a better insulator if moisture in the brick or in the wall space presents as problem. Any thoughts?