Determine Fire Protection Requirements

Submitted by sylvia.wong@up… on Wed, 06/09/2021 - 23:18
Sub Topics

The NCC Section C through to H details the requirements to ensure a level of fire safety is achieved within new construction. These sections are as follows: 

  • Section C: Fire resistance
  • Section D: Access and egress
  • Section E: Services and equipment
  • Section G: Auxiliary provisions
  • Section H: Special use buildings.

These sections all relate and work together to ensure in the event of a fire there is a level of safety and integrity to the construction to assist in saving lives.

The Australian Building Codes Board developed a fire safety presentation, which can be accessed here, this presentation goes into greater depth in relation to how these sections work towards fire safety in new construction.

Before discussing fire safety systems requirements, you must be able to determine the different classes of fire first. This will help you understand the hazards involved and identify the measures and equipment you must use to contain each class of fire. 

Fires are classified according to the materials that fuel them. These are specified in the Australian Standard AS/NZS 1850:2009 portable fire extinguishers, Classification, rating and performance testing. 

A summary of fire classifications and their descriptions can be found below:

Class A

  • Involves carbonaceous solids (contains the chemical element carbon as the basic fuel) such as wood, paper, cloth, plastic, grass, coal or rubber

Class B

  • Involves flammable liquids such as petrol, turpentine, kerosene, tar, paint or wax

Class C

  • Involves flammable gases such as hydrogen, butane or methane

Class D

  • Involves combustible metals such as sodium, magnesium, potassium or aluminium shavings

Electrical

  • Involves materials in Class A and B fires but with introduction of electrical equipment such as wiring, electrical appliances and other electrically energised objects in the vicinity of the fire.
  • Once the electrical equipment is removed from the fire, the classification of the fire changes.
  • Officially there is no Class E fire because electricity is not a fuel. However, it is a source of heat and potential source of electrical shock to a fire.

Class F

  • Involves cooking fats and oils.
  • The temperature of the oils that are on fire is higher than that of flammable liquids. Hence, normal extinguishing methods are ineffective.

Fire safety systems refer to the means and equipment to detect, inform, intervene, or evacuate a building when there is a fire. They typically perform one or a combination of the following functions:

  • Warn occupants when there is an emergency. 
  • Ensure that the conditions for evacuation are safe.
  • Restrict the spread of fire to other parts of the building or adjoining buildings.
  • Suppress fire. 

This short video will explain the different parts or elements, of fire protection systems and how they are designed to protect people and property: 

At the end of the module, in the Summary, you can read about fire protection systems explained in the above video.

The NCC contains Fire Resistance Levels (FRL) requirements for elements used in Type C Fire-Resisting Construction, and it states that a building:

No. Checks
1 a building element listed in Table 5 (NCC Vol 1) and any beam or column incorporated in it, must have an FRL not less than that listed in the Table for the particular Class of building concerned; and
2 an external wall that is required by Table 5 to have an FRL need only be tested from the outside to satisfy the requirement; and
3 a fire wall or an internal wall bounding a sole-occupancy unit or separating adjoining units must comply with Specification C1.8 (NCC Vol 1) if it is of lightweight construction and is required to have an FRL; and
4 in a Class 2 or 3 building, an internal wall which is required by Table 5 to have an FRL must extend—
  • to the underside of the floor next above if that floor has an FRL of at least 30/30/30 or a fire-protective covering on the underside of the floor; or
  • to the underside of a ceiling having a resistance to the incipient spread of fire to the space above itself of not less than 60 minutes; or
  • to the underside of the roof covering if it is non-combustible, and except for roof battens with dimensions of 75 mm x 50 mm or less or sarking-type material, must not be crossed by timber or other combustible building elements; or
  • 450 mm above the roof covering if it is combustible; and
5 in a Class 2 or 3 building, except where within the one sole--occupancy unit, or a Class 9a health-care building, or a Class 9b building, a floor separating storeys, or above a space for the accommodation of motor vehicles or used for storage or any other ancillary purpose, and any column supporting the floor, must—
  • have an FRL of at least 30/30/30; or
  • have fire-protective covering on the underside of the floor including beams incorporated in it and around the column, if the floor or column is or of metal; and
6 in a Class 9c building a floor above a space for the accommodation of motor vehicles or used for storage or any other ancillary purpose, and any column supporting the floor, must—
  • have an FRL of at least 30/30/30; or
  • have a fire-protective covering on the underside of the floor including beams incorporated in it and around the column, if the floor or column combustible or of metal.
A close view of 3 fire extinguishers hung on a wall

As mentioned earlier, passive fire protection measures typically refer to the components and materials that help maintain the structural fire protection of a building. The table below summarises the NCC requirements of passive fire protection elements and the respective Australian Standards.

Passive Fire Protection NCC Requirements Relevant Australian Standards
Fire-resisting building elements
  • Must be constructed entirely of non-combustible materials subject to AS 1530.1 - Combustibility Tests for Materials
  • Must be designed to achieve the fire-resistance level according to the relevant AS
  • AS/NZS 2327, AS 4100 and AS/NZS 4600 if it is a steel or composite structure
  • AS 3600 if it is a concrete structure
  • AS 1720.4 if it is a timber element other than fire-protected timber
  • AS 3700 if it is a masonry structure
Non-combustible building elements

In a type B construction, the following elements must be non-combustible:

  • external walls and common walls, including all incorporated components such as façade framing and insulation
  • flooring and floor framing 
  • shaft (applicable if the shaft is non-loadbearing and not used for discharging hot products)

Examples of non-combustible materials, according to NCC are:

  • plasterboard
  • perforated gypsum lath with a normal paper finish
  • fibrous-plaster sheet
  • fibre-reinforced cement sheeting
  • AS 1530.4
Fire doors
  • Must be able to fulfil all relevant test requirements
  • Must be self-closing which means that the door must fully close immediately every time it is opened
  • Must automatically close when the sensor is triggered or when power supply is lost
  • Must have latch sets and closers marked as required
  • Must have a metal tag attached as required by AS 1905.1
  • AS 1905.1
Fire windows
  • Must be constructed and installed identical to a tested and approved prototype
  • AS 1530.4
Fire shutters
  • Must be constructed and installed identical to a tested and approved prototype
  • Must operate automatically and close at a rate of 0.25 to 0.3 metres per second
  • Must maintain integrity as required
  • AS 1905.2

Smoke doors
  • Smoke should not pass through from one side of the doorway to the other end. If the smoke door is glazed, danger of a person accidentally walking into it must be minimised.
  • Smoke doors can be one or two leaves and must:
    • swing in the direction of egress or both directions
    • resist smoke at 300 degree Celsius for 30 minutes
    • have leaves fitted with smoke seals
  • AS 6905-2007
Proscenium walls (fire curtains)
  • Made of non-combustible material
  • Must stop penetration of smoke around the perimeter when fully lowered
  

On the other hand, active fire protection uses firefighting techniques and equipment to fight the source of a fire and extinguish it. The table below shows active fire protection elements with their respective NCC requirements and Australian Standards.

Active Fire Protection NCC Requirements Relevant Australian Standards

Smoke and heat alarm systems
  • Must be able to sense the presence of a fire and identify its location
  • Must advise the fire brigade if required
  • Must be in a building where sprinklers are not installed
  • Must be connected to a building occupant warning system
  • In places like the kitchen where there is a lot of smoke that can confuse a smoke alarm system, you are advised to install a heat alarm instead
  • AS 3786

Smoke and Heat Detection Systems
  • Must be able to sense the presence of a fire and identify its location
  • Must advise the fire brigade if required
  • Must be able to switch air handling system into smoke ventilating mode
  • Must close smoke and fire-isolating doors as necessary
  • Must activate necessary fire pumps
  • In places like the kitchen where there is a lot of smoke that can confuse a smoke alarm system, you are advised to install a heat alarm instead
  • AS 1670

Fire hose reel systems
  • Must be long enough to reach every floor or storey where it is installed by laying the hose along normal lines of access
  • For 19 mm hoses, there must be a water supply rate of at least 0.33 litres/second
  • For 25 mm hoses, there must be a water supply rate of at least 0.41 litres/second
  • AS 2441

Portable fire extinguishers
  • Must be marked with the class and size of fire for which they have been successfully tested
  • Must be located in conspicuous and accessible locations
  • Locations must have appropriate signage
  • AS 1850
  • AS 2444

Fire hydrants
  • Must be installed according to AS 2419.1
  • Must be located to provide coverage to every part of the building or site that requires coverage
  • Must meet the required minimum flow of water at all times
  • Must be readily accessible to firefighting personnel
  • AS 2419.1

Emergency warning and intercom systems
  • Must have the following facilities:
  • a master emergency control panel (MECP)
  • any necessary additional emergency control panels (ECP)
  • necessary distribution system to transmit a warning signal to each evacuation zone
  • a warden intercommunication point (WIP) on each floor or in each evacuation zone
  • a notice at each ECP with clear instructions on how to operate them
  • an interconnection with the building fire alarm system
  • AS 1670.4

Building occupant warning system
  • Must have a sound system for an emergency that is triggered by the fire-detection system
  • Must have electronic sounders or amplified sound systems that produce an evacuation signal
  • Evacuation signal must operate simultaneously throughout the building
  • AS 1670.4

Emergency escape lighting and signs
  • Be installed according to AS 2993.1
  • Automatically operate when there is power supply failure in the main lighting system
  • Luminance must be appropriate to:
    • the use and size in the floor area of the building
    • the distance to the exits
  • AS 2293.1

Automatic fire sprinkler systems
  • Must comply with AS 2118 (e.g. the sprinkler system must be capable of providing sufficient flow)
  • Must be maintained in accordance with AS 1851-2005 Section 2
  • AS 2118.1
  • AS 2118.4
  • AS 2118.6

Smoke and heat vents

Must have the following components:

  • vents and their operating mechanism
  • draught curtains
  • inlet ventilation
  • AS 2665

Module Linking
M00130A
Main Topic Image
A fire hydrant and hose reel on the outside of a building