53 Pa. Stat. § 24949
The fly galleries entire, including pin rails, shall be constructed of iron or steel, and the floors of said galleries shall be composed of iron or steel beams filled with fireproof materials, and no wood boards or sleepers shall be used as covering over beams, but the said floor shall be entirely fireproof. The rigging loft shall be fireproof, except the floor covering the same. All stage scenery, curtains and decorations made of combustible material and all woodwork on or about the stage shall be saturated with some noncombustible material or otherwise rendered safe against fire to the satisfaction of the bureau of fire. The roof over the auditorium and the entire main floor of the auditorium and vestibule, also the entire floor of the second story of the front superstructure over the entrance lobby and corridors, and all galleries in the auditorium, shall be constructed of iron or steel and fireproof materials, not excluding the use of wooden floor boards and necessary sleepers to fasten the same to, but such sleepers shall not mean timbers of support. The fronts of each gallery shall be formed of fireproof materials, excepting the capping, which may be made of wood. The ceiling under each gallery shall be entirely formed of fireproof materials. The ceiling of the auditorium shall be formed of fireproof materials. All lathing whenever used shall be of metal. The partitions in that portion of the building which contains the auditorium, the entrance, vestibule and every room and passage devoted to the use of the audience shall be constructed by fireproof materials, including the furring of outside or other walls. None of the walls or ceilings shall be covered with wood sheeting, canvas or any combustible material, but this shall not exclude the use of wood wainscoting to a height not to exceed six feet, which shall be filled in solid between the wainscoting and the wall with fireproof materials. The wall separating the actors' dressing rooms from the stage and the partitions dividing the dressing rooms, together with the partitions of every passageway from the same to the stage, and all other partitions on or about the stage shall be constructed of fireproof material approved by the bureau of building inspection. All doors in any of said partitions shall be of iron or of wood constructed as hereinbefore described. All the shelving and cupboards in each and every dressing room, property room or other storage rooms shall be constructed of metal, slate or some fireproof material.
53 P.S. § 24949