That is one of two garage doors. The doors are
constructed of sheet metal. I finally insulated
the darn things. When you live in an area that
can see over night temperatures as low as -20
degrees, it's down right silly to wait 32 years to
insulate. Oh well, no door shall be insulated
before it's time.
So far it has made a difference close to 10 degrees
warmer in the shop.