That’s really interesting to me that they use “board feet” for the coverage. For lumber, board foot is a very specific measurement that means a square foot, one inch thick (so 144 cubic inches). The insulation value is then measured at 2" thick. Unless DIY spray foam means something different by a board foot then coverage is going to half the area at the advertised R value, and roughly a third if you fill in the 2x4 framing cavity.
Professional spray foam is pretty expensive, but it’s probably a way better idea than than this DIY stuff. The mineral wool is probably fine, and I would happily let somebody punch me in the stomach if it meant I didn’t have to mess with fiberglass batts.
That’s really interesting to me that they use “board feet” for the coverage. For lumber, board foot is a very specific measurement that means a square foot, one inch thick (so 144 cubic inches). The insulation value is then measured at 2" thick. Unless DIY spray foam means something different by a board foot then coverage is going to half the area at the advertised R value, and roughly a third if you fill in the 2x4 framing cavity.
Professional spray foam is pretty expensive, but it’s probably a way better idea than than this DIY stuff. The mineral wool is probably fine, and I would happily let somebody punch me in the stomach if it meant I didn’t have to mess with fiberglass batts.