NCC 2019 Volume One Amendment 1
Specification C2.5 Smoke-proof walls in health-care and residential care buildings

Specification C2.5 Smoke-proof walls in health-care and residential care buildings

1. Scope

This Specification sets out requirements for the construction of smoke-proof walls in Class 9a health-care buildings and Class 9c buildings. Smoke proof walls required to have an FRL are to be in accordance with Clause A5.4.

Intent

To prescribe construction requirements for smoke-proof walls required by C2.5 in health-care and residential care buildings.

Specification C2.5 applies to smoke-proof walls in:

  • Class 9a health-care buildings; and
  • Class 9c buildings.

2. Class 9a health-care buildings

Smoke-proof walls required by C2.5 in Class 9a health-care buildings must comply with the following:

(a)

Be non-combustible and extend to the underside of—

(i)

the floor above; or

(ii)

a non-combustible roof covering; or

(iii)

a ceiling having a resistance to the incipient spread of fire to the space above itself of not less than 60 minutes.

(b)

Not incorporate any glazed areas unless the glass is safety glass as defined in AS 1288.

(c)

Only have doorways which are fitted with smoke doors complying with Specification C3.4.

(d)

Have all openings around penetrations and the junctions of the smoke-proof wall and the remainder of the building stopped with non-combustible material to prevent the free passage of smoke.

(e)

Incorporate smoke dampers where air-handling ducts penetrate the wall unless the duct forms part of a smoke hazard management system required to continue air movement through the duct during a fire.

Intent

To prescribe construction requirements for smoke-proof walls required by C2.5 in Class 9a health-care buildings.

Clause 2 applies to smoke-proof walls in Class 9a health-care buildings.

3. Class 9c buildings

Smoke-proof walls required by C2.5 in Class 9c buildings must comply with the following:

(a)

The wall may be lined on one side only.

(b)

Linings on the wall must be non-combustible and extend to the underside of—

(i)

the floor above; or

(ii)

a non-combustible roof covering; or

(iii)

a flush plasterboard ceiling lined with 13 mm standard grade plasterboard or a fire-protective covering, with all penetrations sealed against the free passage of smoke.

(c)

If plasterboard is used in the lining on a wall, it must be a minimum of 13 mm standard grade plasterboard.

(d)

Not incorporate any glazed areas unless the glass is safety glass as defined in AS 1288.

(e)

Only have doorways which are fitted with smoke doors complying with Specification C3.4.

(f)

Have all openings around penetrations and the junctions of the smoke-proof wall and the remainder of the building stopped with non-combustible material to prevent the free passage of smoke.

(g)

Incorporate smoke dampers where air-handling ducts penetrate the wall unless the duct forms part of a smoke hazard management system required to continue air movement through the duct during a fire.

Intent

To prescribe construction requirements for smoke-proof walls required by C2.5 in Class 9c buildings.

Clause 3 applies to smoke-proof walls in Class 9c buildings.

The purpose of the smoke-proof walls is to create a “smoke compartment” to stop or limit the spread of smoke to adjoining areas. It is therefore important that all penetrations of the walls and ceiling of the “smoke compartment” be sealed against the penetration of smoke. This includes any light fitting in the flush plasterboard ceiling referred to in Clause 3(a)(iii).

A wall lining need only be applied to one side of the wall to achieve compliance with Clause 3.

4. Doorways in smoke-proof walls

A door required by C2.5 or this Specification to be smoke-proof or have an FRL, other than one that serves a fire compartment provided with a zone pressurisation system in accordance with AS 1668.1, must provide a smoke reservoir by not extending within 400 mm of the underside of—

(a)

a roof covering; or

(b)

the floor above; or

(c)

an imperforate false ceiling that will prevent the free passage of smoke.

Intent

To limit the spread of smoke between smoke-zones by the use of smoke-reservoirs.