How would you insulate a rim joist on an existing home that currently has next to none? It has 1" styrofoam on the outside of the joist. The insulation goes 5" up the 10" rim joist, leaving a 5" space with just joist, plywood and siding. I don't know how deep the insulation goes.
There is no insulation on the inside of the joist.
Pretty easy access to the inside with a 4' crawl space.
There is rot on the sill plate and rim joist in areas. I will be replacing those.
How would you insulate and seal once the rotted pieces are replaced?
Here are a few pictures....