Specification 17 Fire sprinkler systems

Design and installation—sprinkler systems

S17C1 deals with the intent.

Examples

A number of the Deemed-to-Satisfy Provisions require the installation of sprinklers in accordance with Specification 17. These include:

• E1D4—Sprinklers;
• Part E2—Smoke Hazard Management;
• C3D4—Large isolated buildings;
• Specification 31—Fire and smoke control in buildings containing atriums;
• S5C19, S5C22 and S5C25 of Specification 5 when granting a concession for enclosed carparks;
• S5C10 of Specification 5 for residential care buildings; and
• S5C20 and S5C23 of Specification 5 for multi-storey, timber framed, Class 2 or 3 buildings.

Adoption of three Parts of AS 2118

Specification 17 adopts three Parts of AS 2118:

• AS 2118.1—Automatic fire sprinkler systems Part 1: General systems; and
• AS 2118.4—Automatic fire sprinkler systems Part 4: Residential; and
• AS 2118.6—Automatic fire sprinkler systems Part 6: Combined sprinkler and hydrant.

AS 2118.1 applies to all classes of buildings—S17C2(a)

Part 1 of AS 2118 is applicable to all Classes of building.

AS 2118.4—S17C2(e) and (f)

These clauses allow the use of Part 4 of AS 2118 for Class 2, 3, 9a and 9c buildings as appropriate. The reason for using the term “as applicable” is that AS 2118.4 applies to low-rise Class 2, 3, 9a and 9c buildings. The scope of AS 2118.4 states that it only applies to those buildings containing no more than four storeys. If the building exceeds this height, it must comply with AS 2118.1. While the scope of AS 2118.4 may not mention Class 9a buildings, this is a case where A4G2 applies and the BCA requirement overrules the limited scope in AS 2118.4.

The sprinkler system specified under AS 2118.4 has been designed for use in low-rise residential buildings. AS 2118.4 also takes into consideration the economic aspects of a sprinkler system.

AS 2118.4 provides the requirements for sprinklers in residential buildings.

A sprinkler system installed in accordance with AS 2118.4 is designed to prevent the fire reaching the stage at which “flashover” occurs (i.e. total involvement of a room’s contents in a fire), thus reducing the risks to occupants.

Smoke detection matters are dealt with in Part E2.

Combined sprinkler and hydrant systems—S17C2(d)

S17C2(d) allows the installation of a combined sprinkler and hydrant system provided it complies with AS 2118.6.

Adoption of the Fire Protection Association Australia (FPAA) Technical Specifications

Specification 17 adopts two Technical Specifications developed by FPAA:

• FPAA101D—Automatic fire sprinkler system design and installation — Domestic water supply; and
• FPAA101H—Automatic fire sprinkler system design and installation — Hydrant water supply.

S17C2(b) references Specification 18 providing an option to use automatic fire sprinkler systems complying with FPAA101D or FPAA101H in Class 2 or 3 buildings (excluding residential care buildings) with a rise in storeys of 4 or more and an effective height up to and including 25 metres.

Size and intensity of an assumed fire

The design of a sprinkler system is based on the size and intensity of an assumed fire in the building. The BCA assumes that fire size is controlled by the sprinkler system.

A fire in a non-sprinklered part of a building

If a fire starts in a non-sprinklered part of the building, its development will be uncontrolled. It can even reach a size which could over-ride the sprinkler system if it spreads to the sprinklered part of the building (i.e. it could be beyond the design capacity of the system).

Separation between sprinklered and non-sprinklered parts

S17C3(a) applies wherever there is a specific Deemed-to-Satisfy Provision.

The fire separation required by AS 2118.1, FPAA101D and FPAA101H may differ from that required by the BCA. S17C3(b) clarifies that if a difference exists between AS 2118.1, FPAA101D and FPAA101H and the BCA, the BCA takes precedence.

AS 2118.1 generally requires a 120/120/120 FRL separation between the sprinklered and non-sprinklered parts of a building to minimise the risk of fire spread from non-sprinklered parts (where a fire’s development is substantially uncontrolled) to a sprinklered part (where the sprinkler system is designed on the basis of a likely fire in that part of the building).

The aim of S17C4 is similar to S17C3, but it particularly deals with the protection of openings, in the construction, between sprinklered and non-sprinklered parts of a building.

Where “quick response” sprinkler heads register a specific external temperature, their reaction time is much shorter than for a “normal” sprinkler head. They also have different discharge characteristics. Where “quick response” sprinkler heads are used, the sprinkler system must be designed specifically for their use.

Sprinkler control valves—location

Sprinkler control valves must be located in a secure area to prevent unauthorised tampering or vandalism.

“Direct egress to a road or open space”

S17C6(1) requires that sprinkler alarm valves be in a room having “direct egress to a road or open space”. The intent is to help fire brigade personnel gain quick access to valves, and, if the need arises, to exit quickly.

When interpreting the expression “direct egress to a road or open space”, it should be noted that D2D15(3) requires that if an exit discharges to open space which is at a different level from the public road to which it is connected, the path of travel to the road must be by a ramp or stairway complying with the BCA.

The aim is to provide quick egress, if the need arises. For this purpose it would be reasonable to limit the stairway to one flight. The landing and stairway must not expose a user to fire or smoke generated by a fire in the building. Care must therefore be taken to make sure windows and other openings are correctly located, and that the external walls of the building have an appropriate FRL.

A dual water supply is required for buildings greater than 25 metres in effective height, however a concession for the secondary water supply is permitted in certain circumstances (see S17C7(2)).

At least one water supply is required for buildings with an effective height of 25 m or less (see S17C7(1)).

AS 1670.1

S17C8 requires a sprinkler system (except for FPAA101D systems) to be connected to activate a warning system complying with S20C7. This is an AS 1670.1 warning system which is to operate throughout the occupied parts of the building.

Activation of smoke hazard management system

Modern fire safety designs allow for the interaction of the various safety systems during a fire. S17C9 requires that where a smoke hazard management system is activated by a smoke detector, “wherever practicable” it must also be activated by the sprinkler system.

Note this provision only applies “wherever practicable”. In other words, if a building proposal includes a smoke hazard management system which is activated by smoke detectors, but it is proposed that the smoke hazard management system will not be activated by the sprinkler system, the building proponent must satisfy the appropriate authority that it is not practicable to do so.

Stages used for live performances—high fire load

Stages used for live performances can contain high fire loads due to the scenery and other props used in these productions, and particularly hazardous stage activities, such as pyrotechnics.

S17C10(2) requires that sprinkler valves for systems provided under S17C10(1) be fitted with anti-tamper devices connected to a monitoring panel.

Carparks

S5C19(3) grants concessions for the FRL of structural members within carparks in buildings required to be of Type A construction. Therefore, S17C11 only applies to such buildings.

S17C11 does not apply for carparks in buildings required to be of Type B or Type C construction.

If a building required to be of Type A construction contains an enclosed carpark, in order to take advantage of the concession allowed by S5C19(3), it must contain a sprinkler system which is independent or can be separately isolated.

The reason for this requirement is so that the carpark’s protection is available at all times, and is not affected by such factors as maintenance or shutdown in other parts of the building.

S17C12 allows a sprinkler system in a Class 3 building, a Class 9a health care building used for residential care, or a Class 9c building to comply with AS 2118.4 instead of AS 2118.1. S17C12(2)(a) requires the addition of a monitored main valve and control valve assembly in accordance with AS 2118.1. The reason for the additional requirement is to ensure greater reliability of the sprinkler system.

S17C12(2)(b) specifies system monitoring requirements to enable a timely and appropriate response by the local fire brigade to emergencies.

Not all Class 9b early childhood centres are required to be sprinkler protected. E1D5 and E1D11 are examples of provisions that may require sprinkler protection for a Class 9b early childhood centre. S17C14 requires that sprinklers serving the Class 9b early childhood centre be quick response, except where limitations allow otherwise.

Limitations

Limitation (a) - Direct Egress:
Where the Class 9b early childhood centre is located entirely within a storey with direct access to a road or open space, quick response sprinklers are not required.

Limitation (b) - Limited Rise in Storeys:
Quick response sprinklers are also not necessary where the Class 9b early childhood centre is the only use in a building with a rise-in-storeys not more than 2.