Last year I helped a friend with her basement rim joist problems. The basement was under insulated but cold and floor were always cold and robbing a lot of heat upstairs. When I pulled out the little bit of glass someone stuffed up in the rim joist area cold air just poured in. I foamed the big gap and let it to harden up and when I went back it was amazing how it had changed. We put the glass back in and added more but I don’t think it did much. Stopping the draft was 99% of it.
If you have siding that snaps on its not that hard to take a couple rows down. It may be possible to do some good without taking the ceiling down. Most people dread opening the ceiling but that also isn’t that much to fix if you are careful how you open it up.
Your question is hard to answer because we don’t know the whole picture. You can keep anything warm as toast if you pump enough heat to it. It’s hard to say.
If you have siding that snaps on its not that hard to take a couple rows down. It may be possible to do some good without taking the ceiling down. Most people dread opening the ceiling but that also isn’t that much to fix if you are careful how you open it up.
Your question is hard to answer because we don’t know the whole picture. You can keep anything warm as toast if you pump enough heat to it. It’s hard to say.