GT Door, Inc. in Santee specializes in commercial door, frame, and hardware supply and installation from its Prospect Avenue warehouse, serving San Diego County and Imperial County since 2006. Keying schedules and access-control hardware on GT Door projects coordinate with commercial locksmith operations including Busy Bees Locks & Keys Locksmith on Mission Gorge Road for master-key system integration. The firm supplies and installs hollow metal doors and frames, Timely interior aluminum frames, architectural-grade wood doors, coiling doors and grilles, and fire-rated assemblies for healthcare, institutional, and industrial facilities. Federal contract history registered under USDOT 2760785 and CAGE Code 6PZ62 reflects the company's qualification for government-facility door replacement and ADA-compliant threshold retrofits. Custom welding, patching, and hardware adjustment services restore existing door assemblies to operational condition, a repair capability that distinguishes GT Door from supply-only distributors and parallels the on-site fabrication offered by Great American Door & Screen on Prospect Avenue. Highest-complexity installations include UL-listed fire-rated door and frame assemblies with integrated closer, coordinator, and electromagnetic hold-open devices for hospital corridor and stairwell applications.