Have 100+ old house---stone foundation around perimeter. One area of house has a 20' X 20' space with a crawl space that is only 18" high. I am getting air infiltaration in this space---somewhere around where the sill sits on the stone foundation. I ceratinly can't get close enough to check exactly where infiltration is happening. I need suggestions as to how to insulate. I thought there might be some sort of spray-on foam insulation-with a 4'to 5' long "wand" applicator---that one could spray the heck out of the inside of the stone wall foundation---and up onto the sill---and even up onto a part the the underside of the floor (THAT WOULD TAKE CARE OF THE AIR INFILTARTAION!) what do you think? I need suggestions. If foam--- what kind of foam? If not foam, then what? Oh, by-the-way, I did tuck-point the outside of the stone wall foundation--- and did check for open areas where the siding covers sill. I NEED HELP---Please, respond. Jaes.