I'm just beginning a basement finishing project, so I expect this is my first of many posts.
Right now I'm wondering about whether it would be worthwhile to add insulation to my rim joists. I live in Minnesota and the rim joists that I have are an engineered product that has a layer of foam insulation in the middle--rated R-8. My question is whether I can get away with just throwing in some extra fiberglass batting. I know this is generally not a good idea for the rim joist area, but I thought since there's already foam insulation that that would mean that I already have a pretty good air seal in place. Would the warning against using batting in this scenario still apply? I want to use batting because it seems like it would be quite a bit easier than the alternatives (except the alternative of doing nothing).