My home has poured concrete basement and crawl space walls. There is brick on the outside that continues below the ledger board and over the concrete. I recently noticed that the insulation on the interior crawl space wall had fallen down, so I decided to replace it.
I found the old insulation was chewed up and full of animal feces (chipmunk most likely). It appears there is a gap where there is a notch in the foundation to accept an I beam (photos attached). You can see the back of the brick in the photos of the notch. The cob webs are moving, so there is air flowing through. It doesn't appear wet, and the feces is not fresh. but the I beam is rusty.
I removed the old insulation, but before I replace it, how can I fill the gap? Foam, fiberglass (this was stuffed in previously), concrete? Nothing is wet now, but I am concerned about rust on the I beam. I want to keep moisture and critters out. Any suggestions will be greatly appreciated. I am pretty handy around the house, but I have no idea how to deal with this.