Openings between the stage and auditorium other than the proscenium opening shall not exceed 4 in number, 2 at the approximate stage level and 2 in the musician's pit; the size of any such openings shall not exceed 21 square feet. The openings at stage level shall have an automatic standard fire door on one side of the wall and a self-closing fire door at the other side of the wall, and openings, of any, below the stage shall have a self-closing standard fire door; all of said doors shall be hung so as to be opened from either side of the wall at all times.
All that portion of the stage extending from the stage side of the fireproof curtain and from the fireproof wall separating the space under the stage from the auditorium to the outer edge of the apron shall be fireproof A wood finish floor without air space may be used in front of the curtain and on the stage.
All openings in exterior walls of stage section shall be protected by approved fire doors, shutters or wired glass windows in metal sashes and frames.
All that portion of the stage which is not movable (excepting that part usually embraced between the proscenium jambs and from proscenium to rear wall) shall be of fireproof construction and designed to safely sustain a live load of not less than 100 pounds per square foot. The non-fireproof portion of stage floor shall be of heavy timbers or steel beam construction with flooring not less than 1 3/4 inch finished thickness.
The fly galleries and the tie galleries shall be of fireproof construction designed to safely sustain a live load of 90 pounds per square foot. No wood boards or sleepers shall be used as covering over these floors.
The gridiron or rigging loft shall have a lattice metal floor capable of sustaining a live load of 75 pounds per square foot and be readily accessible by metal stairs.
All stage scenery, curtains and decorations made of combustible material, and all woodwork on or about the stage, shall be painted or saturated with some non-combustible material, or otherwise rendered safe against fire.
There shall be one or more ventilators constructed of metal or other incombustible material, near the center and above the highest part of the stage of every theatre, opera house or motion picture show, raised above the stage roof, and of a combined sectional area equal to at least 10 per cent of the floor area within the stage walls. The openings in such ventilators shall have an aggregate sectional area at least equal to that required for the ventilators. Detailed drawings showing the construction and operation of the ventilators must be approved by the Building Inspector before installation is begun. The entire equipment shall conform to the following requirements or their equivalent:
The construction of the cover and its operating mechanism shall be massive and the cover shall open by force of gravity sufficient to effectively overcome the effects of neglect, rust, dirt, frost, snow or expansion by heat, twisting or warping of the framework.
Glass if used in ventilators must be protected against falling on the stage. A wire screen if used under the glass must be so placed that if clogged it cannot reduce the required vent area or interfere with the operating mechanism, or obstruct the distribution of water from the automatic sprinklers.
The cover shall be arranged to open instantly after the outbreak of fire by the use of approved automatic fusible links of the thinnest metal practicable; manual control also must be provided by a cord run down to the stage at a point designated by the Building Inspector.
The link and cord must hold the cover closed against a force of at least 30 pounds excess counterweight tending to open the cover. Fusible links shall be placed in the ventilator above the roof line and in at least two other points in each controlling cord. No automatic sprinkler heads shall be placed in the ventilator space above the fusible links. Each ventilator cover shall be operated daily while theatre is in use by one of the cords.
If any skylight is placed in a roof, it shall be installed in accordance with the specifications for skylights published by the National Board of Fire Underwriters.
Actors' dressing rooms shall not be placed on or under the stage, or in or under the auditorium. They shall be placed in a separate section provided for that purpose. No dressing room ceiling shall be less than 4 feet, 6 inches above the level of street or court adjoining.
The walls separating said section containing the dressing rooms from the stage or auditorium shall be of brick or concrete not less than 8 inches in thickness and each opening therein shall be protected with a self-closing fire door. The partitions dividing the dressing rooms, together with the partitions of every passageway from the same to the stage shall be constructed of approved fireproof material not less than 4 inches in thickness. All doorways in any of said partitions shall be protected by self-closing fire doors. All dressing rooms shall be ventilated by wired glass windows in metal frames to a street or to a court not less than 24 square feet in area.