I am insulating my rim joists with 2" rigid foam board. Most of the rim joist is bare, and the foam fits along it nicely. Some sill boxes have some small irregularities (vent pipes, plumbing, etc) that I have worked around easily enough.
However, there are many electrical cables running along the rim joist near the circuit breaker box. For a good 10 feet in either direction, there are enough cables that it doesn't seem practical to get the foam board flush against the rim joist. Yes, I could carefully and laboriously cut little channels for each cable in the back of the foam, but that would take a long time.
Is it okay to simply push the foam against the cables and call it good enough? This will leave some air pockets trapped between the foam and the rim joist because the foam will be off of the joist a 1/2" or so (the width of the cables). Will this cause moisture or other problems? Seems it shouldn't as long as I do a good job sealing around the foam board.
(p.s. I know that spray foam would be the ideal solution, but we are trying to avoid that, mostly for cost reasons)