I've got a 2 story balloon- framed home built in 1900. Currently, the rim joist has 0 insulation. We were looking at how we can DIY the insulation, but some of the bays are just gnarly looking. Nothing like what you see on any guide or YouTube video.
I've attached a photo of one of the more gruesome ones. At the top of the bays, you can see a little bit of plaster that has fallen, showing that there is a few more inches before you hit the exterior facing wall. So a gap that we can't touch at all. Also, you can see that the joists don't extend all the way, so bays are opened to the bays next to them. In certain areas, the sub-floor between the basement and floor 1 is wide open. I can literally stick my arm up through to the first floor.
I had 3 different contractors come in to quote out the rim joist. All of them agreed on closed-cell spray foam. But my fear is that some of these gaps are much larger than the the foam will expand to cover. I don't know if they will be able to completely air seal all these bays. I'm fine with a little bit of lost heat, but last thing I want to do is to increase the chances of rot.
So I'm at a loss on what to do ... Do we try to DIY with ridged foam, cutting to fit best we can and filling in the gaps with foam? Do we let the contractors do their thing and just spray everything with CCSF? Or, since this house is 125 years old and hasn't rotted out yet, do we not change anything and just live with cold floors?