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

7

Specification 7 Fire hazard properties

Specification 7 Fire hazard properties

This Specification sets out requirements in relation to the fire hazard properties of linings, materials and assemblies in Class 2 to 9 buildings as set out in Table S7C2.

To set out the scope of Specification 7.

 

It should be noted that C2D11 requires the fire hazard properties of linings, materials and assemblies used in the construction of a building to comply with Specification 7. Specification 7 sets out the details of these requirements.

Linings, materials and assemblies must comply with the appropriate requirement described in Table S7C2.

Table S7C2 Fire hazard property requirements
Lining, material or assembly Requirement
Floor linings and floor coverings S7C3
Wall linings and ceiling linings S7C4
Air-handling ductwork S7C5
Lift cars S7C6
In fire control rooms subject to Specification 6 and fire isolated exits S7C7
In Class 9b buildings used as a theatre, public hall or the like — fixed seating in the audience area or auditorium; and a proscenium curtain required by Specification 32 S7C7
Escalators, moving walkways and non-required non-fire-isolated stairways or pedestrian ramps subject to Specification 14 S7C7
Sarking-type material S7C7
Attachments to internal floors, walls and ceilings S7C7
Other materials including insulation S7C7

To set out clauses in the Specification, that the linings, materials and assemblies must comply with.

Table S7C2 sets out which clauses of Specification 7 linings, materials and assemblies must comply with.

A floor lining or floor covering must have—

  1. a critical radiant flux not less than that listed in Table S7C3; and
  2. in a building not protected by a sprinkler system (other than a FPAA101D or FPAA101H system) complying with Specification 17, a maximum smoke development rate of 750 percent-minutes; and
  3. a group number complying with S7C6(b), for any portion of the floor covering that is continued more than 150 mm up a wall.
Table S7C3 Critical radiant flux (CHF in kW/m2) of floor linings and floor coverings
Class of building Building not fitted with a sprinkler system (other than a FPAA101D or FPAA101H system) complying with Specification 17 Building fitted with a sprinkler system (other than a FPAA101D or FPAA101H system) complying with Specification 17 Fire-isolated exits and fire control rooms
Class 2, 3, 5, 6, 7, 8 or 9b, excluding Class 3 accommodation for the aged and Class 9b as specified below 2.2 kW/m2 1.2 kW/m2 2.2 kW/m2
Class 3 accommodation for the aged 4.5 kW/m2 2.2 kW/m2 4.5 kW/m2
Class 9a patient care areas 4.5 kW/m2 2.2 kW/m2 4.5 kW/m2
Class 9a areas other than patient care areas 2.2 kW/m2 1.2 kW/m2 4.5 kW/m2
Class 9b auditorium or audience seating area used mainly for indoor swimming or ice skating 1.2 kW/m2 1.2 kW/m2 2.2 kW/m2
Class 9b auditorium or audience seating area used mainly for other sports or multi-purpose functions 2.2 kW/m2 1.2 kW/m2 2.2 kW/m2
Class 9c resident use area N/A 2.2 kW/m2 4.5 kW/m2
Class 9c areas other than resident use areas N/A 1.2 kW/m2 4.5 kW/m2

To prescribe the fire hazard properties of floor linings and floor coverings.

S7C3(a) states that a floor lining or covering must have a critical radiant flux not less than that in Table S7C3. A material’s critical radiant flux is determined by testing the material in accordance with AS ISO 9239.1. This test is the floor radiant panel test. The higher a material’s critical radiant flux is, the better the material performs.


The different requirements for materials are based on the building classification, the location of the material in the building and whether the building contains a sprinkler system. The requirements are higher for aged care buildings and health care buildings due to the limited mobility of occupants in those buildings. The requirements are based on research which indicated that the required egress time in these buildings was greater and therefore proposed levels of control needed to be greater.


S7C3(b) contains requirements dealing with a material’s smoke development rate. A material’s smoke development rate is determined by testing the material in accordance with AS ISO 9239.1. This test is the floor radiant panel test. The requirement is only applicable where floor materials and coverings are installed in buildings that do not have a sprinkler system complying with Specification 17. S7C3(b) limits the smoke development rate to not more than 750 percent-minutes.


Table S7C3 does not contain any requirements for Class 9c buildings that do not contain a sprinkler system. The reason for this is because, pursuant to E1D10, all Class 9c buildings must have a sprinkler system installed throughout the building.

(1) A wall or ceiling lining system must comply with the group number specified in Table S7C4 and for buildings not fitted with a sprinkler system (other than a FPAA101D or FPAA101H system) complying with Specification 17 have—

  1. a smoke growth rate index not more than 100; or
  2. an average specific extinction area less than 250 m2/kg.

(2) A group number of a wall or ceiling lining and the smoke growth rate index or average specific extinction area must be determined in accordance with AS 5637.1.

Table S7C4 Wall and ceiling lining materials (material groups permitted)
Class of building Fire-isolated exits and fire control rooms Public corridors Specific areas Other areas
Class 2 or 3, unsprinklered, excluding accommodation for the aged, people with disabilities and children Walls: 1 Walls: 1, 2 Walls: 1, 2, 3 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1, 2 Ceilings: 1, 2, 3 Ceilings: 1, 2, 3
Class 2 or 3, sprinklered, excluding accommodation for the aged, people with disabilities and children Walls: 1 Walls: 1, 2, 3 Walls: 1, 2, 3 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1, 2, 3 Ceilings: 1, 2, 3 Ceilings: 1, 2, 3
Class 3 or 9a, unsprinklered, accommodation for the aged, people with a disability, children and health-care buildings Walls: 1 Walls: 1 Walls: 1, 2 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1 Ceilings: 1, 2 Ceilings: 1, 2, 3
Class 3 or 9a, sprinklered, accommodation for the aged, people with a disability, children and health-care buildings Walls: 1 Walls: 1, 2 Walls: 1, 2, 3 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1, 2 Ceilings: 1, 2, 3 Ceilings: 1, 2, 3
Class 5, 6, 7, 8 or 9b schools, unsprinklered Walls: 1 Walls: 1, 2 Walls: 1, 2, 3 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1, 2 Ceilings: 1, 2 Ceilings: 1, 2, 3
Class 5, 6, 7, 8 or 9b schools, sprinklered Walls: 1 Walls: 1, 2, 3 Walls: 1, 2, 3 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1, 2, 3 Ceilings: 1, 2, 3 Ceilings: 1 ,2, 3
Class 9b other than schools, unsprinklered Walls: 1 Walls: 1 Walls: 1, 2 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1 Ceilings: 1, 2 Ceilings: 1, 2, 3
Class 9b other than schools, sprinklered Walls: 1 Walls: 1, 2 Walls: 1, 2, 3 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1, 2 Ceilings: 1, 2, 3 Ceilings: 1, 2, 3
Class 9c, sprinklered Walls: 1 Walls: 1, 2 Walls: 1, 2, 3 Walls: 1, 2, 3
Ceilings: 1 Ceilings: 1, 2 Ceilings: 1, 2, 3 Ceilings: 1, 2, 3
Table Notes
  1. ”Sprinklered” means a building fitted with a sprinkler system (other than a FPAA101D or FPAA101H system) complying with Specification 17.
  2. ”Specific areas” means within—
    1. for Class 2 and 3 buildings, a sole-occupancy unit; and
    2. for Class 5 buildings, open plan offices with a minimum floor dimension/floor to ceiling height ratio > 5; and
    3. for Class 6 buildings, shops or other building with a minimum floor dimension/floor to ceiling height ratio > 5; and
    4. for Class 9a health-care buildings, patient care areas; and
    5. for Class 9b theatres and halls, etc, an auditorium; and
    6. for Class 9b schools, a classroom; and
    7. for Class 9c buildings, resident use area.

To prescribe the fire hazard properties of wall and ceiling linings.

S7C4 specifies that a material used as a wall or ceiling lining must be a Group 1, Group 2 or Group 3 material and used in accordance with Table S7C4. A material’s group number is determined by testing the material in accordance with AS 5637.1.

For the purpose of the BCA, a Group 1 material indicates the best performing material and a Group 4 material is the worst performing material.

The allowable material group number differences are based on the building classification and the location of the material in the building. It is also dependent on whether the building contains a sprinkler system (other than a FPAA101D or FPAA101H system) in accordance with Specification 17, and whether the material is used as a wall lining or a ceiling lining.

The locations within the building referred to in Table S7C4 are fire-isolated exits, fire control rooms, public corridors, specific areas and other areas. The definition of specific areas differs according to the use of the building. The specific areas are as follows:

  • for Class 2 and 3 buildings, a sole-occupancy unit;
  • for Class 5 buildings, open plan offices with a minimum floor dimension/floor to ceiling height ratio >5;
  • for Class 6 buildings, shops or other buildings with a minimum floor dimension/floor to ceiling height ratio >5;
  • for Class 9a health care buildings, patient care areas;
  • for Class 9b theatres and halls, etc, an auditorium;
  • for Class 9b schools, a classroom; and
  • for Class 9c buildings, resident use areas.

For Class 5 and 6 buildings, the minimum floor dimension and the floor to ceiling height need to be considered when determining “specific areas”. An area is a specific area if the minimum floor dimension/floor to ceiling height ratio is more than 5.

“Other areas” are areas which are not either a fire-isolated exit, a public corridor or a “specific area”.

The requirements differ between the building classifications. These requirements are based on research which indicated that the required egress time differed between the building’s classifications and therefore proposed levels of control needed to be greater.

S7C4(1) contains requirements dealing with a material’s smoke development rate. The requirements only apply where the wall and/or ceiling lining material is installed in a building that does not have a sprinkler system complying with Specification 17 (other than a FPAA101D or FPAA101H system).

Examples

Consider the case of a Class 5 building having a 15 m by 20 m open plan office with a ceiling height of 2.5 m. The building also contains an enclosed office having a floor plan of 3 m by 4 m.

For the open plan office area, as the minimum floor dimension (15 m) divided by the ceiling height (2.5 m) is 6, i.e. more than 5, it would be deemed a “specific area” and therefore wall and ceiling linings in the area would need to comply with the requirements for Class 5 “specific areas”.\

For the enclosed office, as the minimum floor dimension (3 m) divided by the ceiling height (2.5 m) is 1.2, i.e. less than 5, it would not be deemed to be a “specific area” and therefore wall and ceiling linings in the enclosed office would need to comply with the requirements for Class 5 “other areas”.

Rigid and flexible ductwork in a Class 2 to 9 building must comply with the fire hazard properties set out in AS 4254.1 and AS 4254.2.

To specify requirements for air-handling ductwork.

Air-handling ductwork has the potential to cause the rapid spread of fire throughout a building. It is important that the materials used in its construction are appropriate to avoid this potentially dangerous situation. The particular requirements are covered by AS 4254.

Materials used as—

  1. floor linings and floor coverings must have a critical radiant flux not less than 2.2; and
  2. wall and ceiling linings must be a Group 1 material or a Group 2 material in accordance with AS 5637.1.

To specify requirements for lift cars.

Lift cars are small, enclosed spaces, with minimal ventilation and no active fire suppression equipment. They also have no immediate means of egress. The materials used in their construction must be appropriate to avoid a potentially dangerous situation. 

Floor linings and floor coverings must have a critical radiant flux of not less than 2.2, and the wall linings and ceiling linings must be either a Group 1 material or a Group 2 material, which are similar to those required in public corridors.

Materials and assemblies not included in S7C3, S7C4, S7C5 or S7C6 must not exceed the indices set out in Table S7C7.

Table S7C7 Other materials
Material or assembly location Flammability Index Spread-of-Flame Index Smoke-Developed Index
Fire control rooms subject to Specification 19 and fire-isolated exits, other than a sarking-type material used in a ceiling or used as an attachment or part of an attachment to a building element. Note 1 N/A 0 2
Class 9b buildings used as a theatre, public hall or the like: Any part of fixed seating in the audience area or auditorium. N/A 0 5
Class 9b buildings used as a theatre, public hall or the like: A proscenium curtain required by Specification 32. N/A 0 3
Escalators, moving walkways or non-required non fire-isolated stairway or pedestrian ramps subject to Specification 14. N/A 0 5
Sarking-type materials: In a fire control room subject to Specification 19 or a fire-isolated exit or fire control room used in the form of an exposed wall or ceiling. 0 N/A N/A
Sarking-type materials: In other locations. Note 2 5 N/A N/A
Other materials or locations and insulation materials other than sarking-type material. Notes 2 and 3 N/A 9 8 if the Spread-of-Flame Index is more than 5
Table Notes
  1. In a fire control room or fire-isolated stairway, a material used as an attachment or part of an attachment to a building element must, if combustible, be attached directly to a non-combustible substrate and not exceed 1 mm finished thickness.
  2. A material, other than one located within a fire-isolated exit or fire control room, may be covered on all faces by concrete or masonry not less than 50 mm thick, as an alternative to meeting the specified indices.
  3. In the case of a composite member or assembly, the member or assembly must be constructed so that when assembled as proposed in a building—
    1. any material which does not comply with this Table is protected on all sides and edges from exposure to the air; and
    2. the member or assembly, when tested in accordance with Specification 3, has Spread-of-Flame Index and Smoke-Developed Index not exceeding those prescribed in this Table; and
    3. the member or assembly retains the protection in position so that it prevents ignition of the material and continues to screen it from access to free air for a period of not less than 10 minutes.
Delete table (S7C7) and insert NSW table (S7C7) as follows:
NSW Table S7C7: Other materials
Material or assembly location Flammability Index Spread-of-Flame Index Smoke-Developed Index
Fire control rooms subject to Specification 19 and fire-isolated exits, other than a sarking-type material used in a ceiling or used as an attachment or part of an attachment to a building element. Note 1 N/A 0 2
Class 9b buildings used as an entertainment venue, a material used to cover closed back upholstered seats in any part available to the public—where smoking is permitted; or flame is exposed in connection with the preparation of meals Note 4 N/A 6 5
Class 9b buildings used as an entertainment venue, a material used as a curtain, blind or similar decor in any part available to the public. Notes 4 and 5 6 N/A N/A
Class 9b buildings used as an entertainment venue, a material used to form a cinematograph screen. Notes 4, 5 and 6 12 0 7
Class 9b buildings used as a public hall or the like: A proscenium curtain required by Specification 32. N/A 0 3
Escalators, moving walkways or non-required non fire-isolated stairways or pedestrian ramps subject to Specification 14. N/A 0 5
Sarking-type materials: In a fire control room subject to Specification 19 or a fire-isolated exit used in the form of an exposed wall or ceiling. 0 N/A N/A
Sarking-type materials other than in a fire control room subject to Specification 19 or a fire-isolated exit used in the form of an exposed wall or ceiling. Note 2 5 N/A N/A
Other materials or locations and insulation materials other than Sarking-type materials. Notes 2 and 3 N/A 9 8 if the Spread-of-Flame Index is more than 5
Note
  1. In a fire control room or fire-isolated stairway, a material used as an attachment or part of an attachment to a building element must, if combustible, be attached directly to a non-combustible substrate and not exceed 1 mm finished thickness.
  2. A material, other than one located within a fire-isolated exit or fire control room, may be covered on all faces by concrete or masonry not less than 50 mm thick, as an alternative to meeting the specified indices.
  3. In the case of a composite member or assembly, the member or assembly must be constructed so that when assembled as proposed in a building—
    1. any material which does not comply with this Table is protected on all sides and edges from exposure to the air; and
    2. the member or assembly, when tested in accordance with Specification 3, has a Spread-of-Flame Index and Smoke-Developed Index not exceeding those prescribed in this Table; and
    3. the member or assembly retains the protection in position so that it prevents ignition of the material and continues to screen it from access to free air for a period of not less than 10 minutes.
  4. Any fire-retardant coating used in an entertainment venue to make a material comply with a required Flammability Index, Spread-of-Flame Index or Smoke-Developed Index must be certified by—
    1. its manufacturer or distributor—
      1. as approved for use with the fabric to achieve the required indices; and
      2. to retain its retardancy effect after a minimum of 5 commercial dry cleaning or laundering operations carried out in accordance with AS 2001.5.4, Procedure 7A, using non-phosphate ECE reference detergent A (without optical brightener); and
    2. the applicator as having been carried out in accordance with the manufacturer’s specification.
  5. Materials used in an entertainment venue must have a label affixed to a representative sample of each different material indicating, in legible characters—
    1. name of manufacturer; and
    2. trade name and description of material’s composition; and
    3. retardant treatment (if any), name of applicator and date of application; and
    4. AS 1530 Part 2 and/or AS/NZS 1530 Part 3 test number and its Flammability Index, Spread-of-Flame Index and Smoke-Developed Index; and
    5. approved methods of cleaning.
  6. A cinematograph screen must have a supporting frame of metal construction.

To specify requirements for other locations and materials.

S7C7 sets out requirements for materials and assemblies not included elsewhere in Specification 7. The detail is located in Table S7C7. It is important to read the notes to this table because they contain specific requirements.

Fire-isolated exits and fire control rooms          

Because fire-isolated exits are considered a safe place for people seeking egress during a fire, it is acknowledged that they should be as safe as possible.

Similarly, fire control rooms are part of a building set aside for the fire brigade to co-ordinate its search, rescue and firefighting operations during a fire. Since fire control rooms are used by the fire brigade during a fire, they should also be a safe as possible.

An aim of Table S7C7 is to minimise the risk of a fire in a fire-isolated exit and a fire control room.

It could be claimed that fire is unlikely to enter either of these spaces because of their construction and protection, and therefore there is no need for control of the finishes within them. However, compromising the integrity of these spaces is not at all unusual. For example, by —        

  • removal, alteration or deterioration of fire doors; or  
  • wedging open fire doors in fire-isolated stairways

The prescribed Spread-of-Flame Index and Smoke-Developed Index measures aim to limit finishes to those that are no more hazardous than a conventional paint finish on a non-combustible surface.

The requirements for sarking-type materials in a fire-isolated exit or fire control room are contained under the heading of sarking-type material.

Class 9b theatres, public halls and the like          

To minimise the spread of fire and smoke in a Class 9b building used as a theatre, public hall or the like, Table S7C7 contains specific requirements for —

  • fixed seating used by the audience; and
  • proscenium curtains.

Escalators, non-required non fire-isolated stairways and ramps, etc.          

Table S7C4 contains requirements for materials not listed elsewhere in Specification 7, used in stairways, ramps and escalators not required by the BCA, and which are non fire-isolated. These requirements aim to prevent the spread of fire through an unrestricted number of floors through unprotected openings for stairways, ramps and escalators. Further requirements for escalators, non-required non fire-isolated stairways and ramps can be found in D2D17 and Specification 14.

Sarking-type material          

The requirements in Table S7C7 for a sarking-type material, in areas other than fire-isolated exits and fire control rooms, to have a Flammability Index of not more than 5 is to minimise the risk of sarking facilitating the spread of fire.

As explained above, fire-isolated exits are considered a safe place for people seeking egress during a fire. Likewise, fire control rooms are spaces used by the fire brigade during a fire. Accordingly, both spaces should be as safe as possible and the required Flammability Index is more restrictive.

Other materials          

The other materials referred to in Table S7C7 are materials not referred to in other parts of Specification 7 and elsewhere in Table S7C7. Such materials include, but are not limited to the following:

  • Window frames other than timber window frames (timber window frames are exempt from the requirements of Specification 7, see C2D11(3)).
  • Attachments to walls, floors and ceilings.