garage insulation

I'm not 100% on what you should do. Does the building even have a ceiling? There is probably insulation that can be blown right on the walls. It would be a good insulator and fire proof. I think before you do this yourself you should call an insulation contractor. More than likely they can do the job for less than you can get the material for. I like to build my own houses and always call an insulation guy. Top of the line insulation, fire proof, and done in a day or so. No mess at all. Always save a grand or two.