Bonnie from Briar Lake, B.C. has a metal door that goes into her garage and it is constantly freezing shut with a little accumulation of ice. What to do? The easiest solution is to put some form of plastic, slippery tape on at least one side of the door or the frame where it freezes. We found a roll of Polyolefin tape but sometimes you can even find Teflon tape. These are usually industrial products sold by companies like Green Belting in Buffalo, NY. Check your local Yellow Pages for "tape", you might be surprised at what you find. The ice won't stick to the plastic.
If the rubber cushion bottom of the big garage door tends to freeze to the concrete, spray it with PAM, the cooking spray. Petroleum oils can degrade the rubber. The oil won't last forever but as long as it is there, the rubber won't stick to the ice.