Rodent holes in fiberboard sheathing--best way to patch?
I'm remodeling the kitchen, bath, and laundry in a 1967 brick-clad ranch with fiberboard sheathing. This place has been a basket case with numerous undisclosed problems, one of which was a mouse infestation which I dealt with immediately. This included finding and securing all entry points along the foundation and ongoing maintenance of traps. So far, so good.
The walls were originally insulated with dense-pack cellulose (very effective, based on thermal images) that was blown in through 2" holes in the sheathing before the brick went up. I have opened the kitchen walls and removed the old insulation to run new plumbing and electrical and found a few holes where rodents had chewed through the sheathing from inside the brick-sheathing air gap. Once inside the wall, I don't believe they went far in the cellulose. Access to the brick-sheathing air gap was most likely from inside the crawlspace via the vent areas.
I want to patch the sheathing to prevent re-entry and air seal the wall assembly without inhibiting vapor transport and causing a mold problem. I was considering just cutting some small pieces of 22 gauge sheet metal and gluing it over the few holes I've found (four total). The original insulation blow-in holes appear to be patched only with a black cardboard that has not been chewed. Would be great to prevent creature reentry, since the walls will be covered with rather expensive cabinets, but that is probably best approached by removing access to the structure, rather than lining the walls with chicken wire or plywood. Above all I don't want to trap moisture in the wall and cause mold or rot. What would you do in this case?