I am wondering if anyone has installed rigid foam insulation in between rafters? I have a 100+ year old home in Grand Rapids MI with a full walk up attic, with two by six rafters. In order to get the best R value and to be able to do this myself I figure the rigid foam boards would work best. I was thinking of cutting them to fit and using the expanding foam cans to fill in any gaps. I have found a place that I can get reclaimed/recycled foam boards by the pallet at a significantly reduced price. I would leave some room for venting and use blown in cellulose in the knee walls and ceiling to get the needed R value. I have been researching this for awhile and have not Found any posts or info on this.