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Insulating a brick wall?

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?

Re: Insulating a brick wall?

You've got several approaches here, and all are better than nothing. Sprayed foam would be best, but it costs most and is best done with the walls open and the sheetrock removed. Also with walls open, fiberglass at that thickness will be very effective. With the walls unopened, cellulose can be blown in and the needed holes patched more easily than opening the whole wall, but it settles over time. If you can finish sheetrock and want a big job for your spare time, I'd go with either of the first two. If not, I'd go with the blown-in. If you do fully open the walls, caulk all the wall penetrations (wires, pipes, and ducts) top and bottom with intumescant "Fire Caulking"- back in the 70's this wasn't done but it's code now and a good idea regardless as it will help seal for insulation purposes too.

Some other things to consider is that you may want to also upgrade the insulation in your attic if it needs it- most thermal loss occurs up there. There is probably fiberglass in the floors already. The main thing to consider is that you may be needing approval from the Condo management or HOA, as any shared or exterior walls are usually considered to be in their realm, not the owner's. I can't see them objecting but get it in writing that what you're doing is OK by them first. And know that you're not going to be adding much if anything to the resale value, but the benefits to you will probably be worth it if you're going to be living there awhile.


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