Sealing rim joists
A weatherization company came in today to weatherize our house as part of a county program.
To seal the rim joists in the basement (the ones that weren't drywalled over) they cut paper-backed fiberglass insulation and stuffed them in the cavities.
My understanding is the best way to do this is spray in foam. The next best way is with foam board insulation and seal with spray foam around the edges. Both of those are not cost effective for the county, so they use the R19 roll cut to size.
Is there much insulating value in just the batting stuffed in the rim joists? Is there anything I can do to help beef up the air barrier? The rooms above this space, and specifically the walls, are quite cold in the winter. Another company had said that was from unconditioned air leaking up through the uninsulated rim joists. So if I can temper down the air flow, it should make the upper rooms warmer in theory, right?