Specifications include, but are not limited to: a. Repair of one existing damaged disc; b. Installation of the repaired disc in the existing disc support grid; c. Inspection and repair of the overall existing disc support grid system; d. Inspection and repair of all the existing disc primary hangers; e. Installation of secondary safety hangers on all discs; Repair Damaged Disc Scope: 2.01 One 9’ diameter disc is removed from the theater and is located backstage in the APAC. The disc has been damaged and shall be repaired to original condition. The work includes: a. Repair tear in disc surface with exposed surface finish blended to match existing. Reinforcement may be added to the concealed (top) side of the disc.; b. Reinforce attachment tabs to provide connection to disc rim that is equal or greater in strength to original.; c. Replace double L 1 x 1 x 1/8” angle backing.; d. After repair paint to match existing color.; 2.02 The existing disc is fabricated from 0.200” thick fiberglass with a smooth exposed surface. The attachment tabs are perforated steel plate that are cast into the fiberglass rim of the disc. The angle backing is welded to the tabs.; 2.03 Estimated weight of disc is 200 lbs.; Reinstall Repaired Disc Scope: 3.01 Reinstall the repaired 9’ diameter disc in its original position in the existing disc support grid.; a. Inspect existing disc support grid to ensure existing channels and strut are undamaged. Replace any damaged grid components.; b. Install disc with new primary hangers (rods and nuts), one hanger in each quadrant (four total).; c. Install secondary safety hangers (cable loops), one hanger in each quadrant (four total).; 3.02 Estimated weight of disc is 200 lbs.; Inspect / Repair Existing Disc Support Grid System Scope: 4.01 The existing disc support grid system consists of a horizontal grid constructed of strut (1- 5/8” x 5/8” perforated) and rolled steel channels (C3x5). The channels are supported by the existing soffits, existing catwalks, and from the building structure using steel angle hangers. The strut spans across the top of the channels and is aligned with connection points on the discs.; 4.02 The existing strut are connected to the channels at some intersections, but not all. The work includes: a. Inspect the existing grid connections.; b. Install new screws at any intersections that have missing connectors.; 5 Inspect / Repair Existing Disc Primary Hangers Scope: 5.01 Each disc is hung with four each ¼”all-thread rods (one per disc quadrant). The rods are passed between the back-to-back disc backing angles with a washer and nut retainer below. The rods are connected to the strut with rod clamps. The work includes: a. Inspect the existing primary hangers.; b. Install new primary hangers at all locations where the existing hangers are damaged.; c. Modify the lower rod end connections to be locked connections by either adding a lock nut if the rod length allows or replacing the existing nut with a locking nut.
