So from what I've read spray foam is the best but it is also very expensive I'm trying to figure out what to get for my 40x48 14ft ceilings with 16ft of it vaulted it's a pole building it has 6in of concrete and has in floor heat ran by natural gas boiler. My neighbor just got his 30x30 spray foam and was just under 4k that included ceiling. Being that my building is almost twice the size I don't think I'll wanna spend that kind of money. My friend got reclaimed foam insulation real cheap so I thought about doing that. Or could always go with fiberglass insulation I did have them put the bookshelveing in it. I live in pa so Winters we see negative temperatures. Looking to be efficient but not break the check book to bad. I have free gas but still doesn't mean I wanna waste it.