I live in Buffalo, NY and have a 1920's double with a walk up attic. I currently have no attic insulation. My attic floor prevents me from laying batts without ripping up the entire floor, and cellulose is not an option because of my old wiring. I could blow in fiberglass, and have also considered expanding foam (neither of which is a good option right now because i need to contiune to have access for rewiring). i guess That leaves the underside of the rafters. I was thinking of useing a foil faced R30, because i do have some icedaming issues. I guess my question is what would you all recommend?