Insulate rim joists in concrete / Discussions

How to properly insulate rim joists embedded in concrete in a home built in 50s?

...inking to insulate from the inside - many contractors suggested blowing foam to fill up those gaps - but I also read that effectively sealing off the rim joists could lead to rot - end of joists would no longer dry out? Would it be better to insulate from the exterior? Wouldn't that trap all vapour inside during summer...

Posted by GP Mitchell May 30, 2025 Foundation and basement improvements 2 responses