I have a large block wall in my attic that I share with my neighbor, and both of our attics are unconditioned. This wall tends to radiate a lot of heat during the summer. I'm looking for advice on how to insulate my side effectively. I also have some plans to insulate the rest of the attic next Spring. Any suggestions?
1 Answer
You might want to consider gluing foam board directly onto the wall or framing it out with rockwool and then adding foam board on top. But keep in mind, if the rest of your attic isn’t insulated, insulating just this wall might not make a big difference overall. It's best to tackle insulation as a whole instead of just focusing on one part.

I was thinking about gluing foam board too! Should I spray foam where the board meets the existing framing? Also, does the foam board need foil? I'm planning on adding a radiant barrier under the roof as well. Right now, there's some insulation between the living spaces below, but it needs more work, so I’m considering adding more next Spring along with sealing gaps.