Reuben writes from Gorham, New Hampshire: "I'm insulating my 1.5 car garage, turning it into a woodshop. I can insulate the 2x4 walls with fiberglass and then screw on a 1" foil backed form board and the cover it all with sheetrock, as you've described elsewhere in your blog. For the ceiling I am considering options. Raise the collar ties a bit and install sheetrock or 1/2" plywood for ceilings, then adding 12-24" of fiberglass batts on top. Or I could insulate the rafters (2x6) with fiberglass and foam board and sheetrock it, in order to keep the ceiling as high and as open as possible. With the latter, what is your recommendation? With the former, is there an ideal amount of fiberglass in the ceiling? Garage is 22'x18'."

Answer: You may do either. Just be sure to use unfaced FIBERGLAS™ insulation with at least one inch of FOAMULAR™ extruded foam insulation. Or install Kraft-faced R-19 or R-21 between the 2x6 rafters. Kraft facing should be installed toward the warm-in-winter side.