Single-vehicle garage doors are 8 to 10 feet wide, and double-vehicle garage doors are 12 to 20 feet wide. Garage door heights are usually 7 feet high, but 8- and 10-foot heights are available ...

Double garage doors are 16 or 18 feet wide, so they would need to be cut in half unless you want a really long bed that requires extra support in the center to keep them upright. The height of ...