I have wooden garage doors on a two car garage. One half the garage is sealed off as my shop, with heating. I bought a fiberglass insulation kit for the doors, and the sections of insulation just hang on the back of the panels with plastic clips. I've glued these on with liquid nails, but they still fall off once in a while, and portions hang down when i open the door. I put up a rubber seal around the outside edge of the door too to try to seal air leaks a little better (not sure it does much).
The doors are 30 years old, and the lower panels are very warped and starting to rot in the corners of the panels. I've kept them painted and they're stable enough, but will rot through eventually. I'm trying to decide if it's worth replacing it with a steel insulated door.
They would probably look a little nicer. Would they really be better for heating (they advertise as R-13)? would they seal at the edges better than the wood door?