Space-Saving Vertical-Opening Industrial Sectional Overhead Door For Mezzanine Loading Zones A Space-Saving Vertical-Opening Industrial Sectional Overhead Door is designed for mezzanine-level loading zones where headroom and floor space are both at a premium. The door panels rise vertically and tuck into the ceiling void, so mezzanine walkways, staging areas, and equipment remain unobstructed. Vertical Operation That Protects Mezzanine Space The space-saving vertical opening