410.3.3 Exterior stage doors.

Where protection of openings is required, exterior exit doors shall be protected with fire door assemblies that comply with Section 716. Exterior openings that are located on the stage for means of egress or loading and unloading purposes, and that are likely to be open during occupancy of the theater, shall be constructed with vestibules to prevent air drafts into the auditorium.

410.3.4 Proscenium wall.

Where the stage height is greater than 40 feet (12 192 mm), all portions of the stage shall be completely separated from the seating area by a proscenium wall with not less than a 2-hour fire-resistance rating extending continuously from the foundation to the roof.

410.3.5 Proscenium curtain.

Where a proscenium wall is required to have a fire-resistance rating, the stage opening shall be provided with one of the following:

   1.   A fire curtain complying with NFPA 80; or

   2.   An approved stage water curtain and sprinklers complying with Section 410.7 and Section 903.3.1.1 of this code, and the following:

      2.1.   A deluge valve actuated by a "rate of rise system" and "fixed temperature system" shall control the water curtain system;

      2.2.   The heat actuating devices shall be located on not more than 10-foot (3048 mm) centers around the perimeter of the sprinklered area stage or as otherwise required for the type of device used to assure operation of the system;

      2.3.   In addition to the automatic controls, manual-operating devices shall be located at the voice/alarm communication system required by Section 410.9, and adjacent to at least one exit from the stage. Such exit shall be remote from the voice/alarm communication system;

      2.4.   All valves controlling deluge and sprinkler supplies on stages where the stage height is greater than 40 feet (12 192 mm) shall be provided with tamper switches wired to an annunciator panel located at the voice/alarm communication system required by Section 410.9;

      2.5.   The operation of any section of the sprinkler system on stages where the stage height is greater than 40 feet (12 192 mm) or the operation of the deluge system shall activate the emergency ventilating equipment required in Section 410.3.7 and shall be provided with central station supervision in addition to the required local alarm; and

      2.6.   The water flow alarm, tamper switches, the sprinkler system on stages where the stage height is greater than 40 feet (12 192 mm), and deluge system equipment shall be provided with central station supervision in addition to the required local alarm.

(Am. L.L. 2023/077, 6/11/2023, eff. 6/11/2023)

Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 2023/077.

410.3.6 Scenery.

All scenery or scenic elements shall be of noncombustible materials, or of materials having a flame-spread rating not exceeding 25, or of materials that have been rendered flameproof in compliance with the rules of the Fire Commissioner. Scenery and scenic elements not complying with the above requirements may be used only when expressly permitted by the Fire Department.

410.3.7 Stage ventilation.

Emergency ventilation shall be provided for stages larger than 1,000 square feet (93 m 2 ) in floor area, or with a stage height greater than 40 feet (12 192 mm). Such ventilation shall comply with Section 410.3.7.1 or 410.3.7.2.

410.3.7.1 Roof vents.

Two or more vents constructed to open automatically by approved heat-activated devices and with an aggregate clear opening area of not less than 5 percent of the area of the stage shall be located near the center and above the highest part of the stage area. Supplemental means shall be provided for manual operation of the ventilator. Curbs shall be provided as required for skylights in Section 2610.2. Vents shall be labeled.

410.3.7.2 Smoke control.

Smoke control in accordance with Section 909 shall be provided to maintain the smoke layer interface not less than 6 feet (1829 mm) above the highest level of the assembly seating or above the top of the proscenium opening where a proscenium wall is provided in compliance with Section 410.3.4.

410.4 Platform construction.

Permanent platforms shall be constructed of materials as required for the type of construction of the building in which the permanent platform is located. Permanent platforms are permitted to be constructed in accordance with the following:

   1.   The area below the platform shall be enclosed on all sides with solid construction.

   2.   Platforms constructed of untreated wood shall not exceed an area of 400 square feet (37 m 2 ). Platforms constructed of fire retardant treated wood shall not exceed an area of 1,200 square feet (111 m 2 ). Platforms constructed of noncombustible materials shall not be limited in area.

   3.   Where wood is used, the floor of the platform shall be a least 1 inch (25 mm) nominal thickness. Such floor shall be laid on a solid, noncombustible backing, or shall have all spaces between supporting members fire blocked with noncombustible material.

Where the space beneath the permanent platform is used for storage or any other purpose other than equipment, wiring or plumbing, the floor construction shall not be less than 1-hour fire-resistant construction. Where the space beneath the permanent platform is used only for equipment, wiring or plumbing, the underside of the permanent platform need not be protected.

410.4.1 Temporary platforms.

Platforms installed for a period of not more than 30 days are permitted to be constructed of any materials permitted by this code. The space between the floor and the platform above shall only be used for plumbing and electrical wiring to platform equipment.

410.5 Dressing and appurtenant rooms.

Dressing and appurtenant rooms shall comply with Sections 410.5.1 and 410.5.2.

410.5.1 Separation from stage.

The stage shall be separated from dressing rooms, scene docks, property rooms, workshops, storerooms and compartments appurtenant to the stage and other parts of the building by fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both. The fire-resistance rating shall be not less than 2 hours for stage heights greater than 50 feet (15 240 mm) and not less than 1 hour for stage heights of 50 feet (15 240 mm) or less.

410.5.2 Separation from each other.

Dressing rooms, scene docks, property rooms, workshops, storerooms and compartments appurtenant to the stage shall be separated from each other by not less than 1-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both.