NCC 2022 Volume One - Building Code of Australia Class 2 to 9 buildings

32

Specification 32 Construction of proscenium walls

Specification 32 Construction of proscenium walls

This Specification contains the requirements for the construction of proscenium walls for theatres, public halls, or the like.

 

This Specification provides the requirements for the construction of proscenium walls for theatres, public halls or the like.

(1) Dressing rooms, scene docks, property rooms, workshops, associated store rooms and other ancillary areas must be—

  1. located on the stage side of the proscenium wall; and
  2. separated from corridors and the like by construction having an FRL of not less than 60/60/60, and if of lightweight construction, complying with Specification 6.

(2) The stage and backstage must be separated from other parts of the building other than the audience seating area by construction having an FRL of not less than 60/60/60, and if of lightweight construction, complying with Specification 6.

(3) Any doorway in the construction referred to in (1) and (2) must be protected by a self-closing –/60/30 fire door.

 

A stage and backstage area of a theatre or public hall has a high fire load. It is also a potential fire source due to stored props and scenery, etc.

Specification 32 deals with how to provide fire separation by a proscenium wall between the stage and backstage areas, and other parts of the building, including those occupied by an audience.

A proscenium wall must—

  1. extend to the underside of the roof covering or the underside of the structural floor next above; and
  2. have an FRL of not less than 60/60/60, and if of lightweight construction, comply with Specification 6.

 

The height and extent of a proscenium wall are similar to those of a fire wall.

Timber purlins or other combustible material must not pass through or cross any proscenium wall.

 

Combustible materials must not penetrate any proscenium wall.

Every opening in a proscenium wall must be protected—

  1. at the principal opening, by a curtain in accordance with S32C6 which is—
    1. capable of closing the proscenium opening within 35 seconds either by gravity slide or motor assisted mechanisms; and
    2. operated by a system of automatic heat activated devices, manually operated devices or push button emergency devices; and
    3. able to be operated from either the stage side or the audience side of the curtain; and
  2. at any doorway in the wall, by a self-closing –/60/30 fire door.

 

Any openings in a proscenium wall must be suitably protected to prevent the spread of a fire to the audience side.

An important part of avoiding the spread of fire from the stage is the protection of the opening to the stage. Protection must be provided while still permitting the audience to view a performance.

A curtain required by S32C5 must be—

  1. a fire safety curtain—
    1. made of non-combustible material; and
    2. capable of withstanding a pressure differential of 0.5 kPa over its entire surface area; and
    3. so fitted that when fully lowered it inhibits the penetration of smoke around the perimeter of the opening, from the stage; or
  2. a curtain—
    1. having fire hazard properties complying with Specification 7; and
    2. protected by a deluge system of open sprinklers installed along the full width of the curtain.

 

Since the opening is too large to protect with an automatically-closing fire door, the aim of providing protection while maintaining functionality is achieved by the use of a proscenium curtain. S32C6 gives two alternative options for such a curtain.