A garage door is a large door on a garage that opens either manually or by an electric motor (a garage door opener). Garage doors are frequently large enough to accommodate automobiles and other vehicles. Small garage doors may be made in a single panel that tilts up and back across the garage ceiling. Larger doors are usually made in several jointed panels that roll up on tracks across the garage ceiling, or into a roll above the doorway. The operating mechanism is spring-loaded or counterbalanced to offset the weight of the door and reduce human or motor effort required to operate the door. Less commonly, some garage doors slide or swing horizontally.The insulated steel door is the ideal choice. This series of doors feature sandwich construction of steel-polyurethane-steel as well as between-section seals with thermal breaks to reduce air infiltration. With several panel designs to choose from, these doors offer design flexibility, durability and thermal efficiency that will help keep your home comfortable in cold or hot climates.