Passive Fire Protection in Buildings
Help & Advice
Considerable evidence exists to show that, in a large proportion of buildings, passive ﬁre protection is not being eﬀectively designed, speciﬁed and delivered.1 This potentially poses a serious life safety risk for building occupants and ﬁreﬁghters in the event of ﬁre occurring, as well as increasing risk of ﬁre spread and subsequent property damage. There is an overwhelming need for comprehensive guidance on how to design, specify, install, inspect, certify and maintain eﬀective and resilient passive ﬁre protection in New Zealand buildings.
The purpose of the guide is to enable the eﬀective use of passive ﬁre protection including providing the right product and installing it correctly in the right situation. It describes good practice for the speciﬁcation, approval, installation and veriﬁcation of passive ﬁre protection. Speciﬁc processes may vary between jurisdictions and
the professional people involved, but in all cases, the appropriate product must be correctly installed.
This guide introduces the principles of passive ﬁre protection. It identiﬁes the requirements of the New Zealand Building Code (NZBC), explains the terminology commonly used and identifies the main building components that have a passive fire protection role.
WHAT IS PASSIVE FIRE
Passive fire protection refers to the use of construction elements within a building that are designed to prevent or delay the spread of fire and/or smoke to different parts of the building. Passive fire protection is one of the methods used to protect buildings and people from fire. Other methods that may also be used include active fire protection such as fire sprinklers and alarms. This is supported by good fire safety management to ensure that fire protection is available at all times, facilitating escape in the event of fire and preventing damage to adjacent buildings.
Figure 1 illustrates the various forms of passive fire protection (adapted from AS 1851-2012 Routine service of fire protection systems and equipment). Each may also provide smoke separation as well as fire resistance.
The purpose of passive fire protection is to limit the effects of fire within a building by acting as a barrier to fire and smoke (Figure 2) or protecting structural components from fire that may cause early collapse. This is achieved by installing fire resistance rated elements of construction and controlling the flammability of construction materials. These materials are part of the building fabric and do not include building contents.
TWO KEY ASPECTS OF PASSIVE FIRE PROTECTION
◼ resistance to fire – mainly concerned with the ability of a fire-separating element (such as a wall or floor/ceiling) to limit fire spread, including passage of fire products through the element, or to prevent collapse in the case of a loadbearing element (such as a column)
◼ reaction to fire – mainly concerned with the surface burning behaviour of an element or material (for example, Material Group Numbers) and the extent to which it promotes rapid flame spread or smoke production.
NEW ZEALAND BUILDING CODE AND
The minimum requirements for fire protection in buildings are given by the NZBC. The NZBC is performance based, with a set of mandatory performance requirements.
Whether the building is a new build, existing building or a refurbishment, the requirements of the NZBC, via the Building Act, must be met.
Meeting NZBC requirements may be achieved by:
◼ compliance with the Acceptable Solutions
◼ following a Verification Method
◼ an Alternative Solution
◼ an ‘as near as reasonably practicable’ (ANARP) solution for change of use or alterations in existing buildings.
Attention to detail and installation quality is essential for the passive fire protection to perform its function.
Once the consent documentation has been provided and a building consent has
been issued, passive fire protection must be installed as specified in the consented documents and in accordance with any agreed quality assurance processes. This means in accordance with all supporting information supplied to the BCA, including manufacturers’ instructions.
Where a performance specification only has been submitted in consent documentation, the subsequent process needs to be agreed with the BCA to ensure the selection and installation of the passive fire protection system will comply with the NZBC.
Any deviations from the consented documents or design specifications, such as a substitution of materials or components, must be approved via a consent amendment by the BCA before the change is made. This is to ensure that Code compliance is not compromised by the proposed change. The BCA documents and records the change(s) if approved.
It is important that the passive fire building elements are installed in accordance with the consented documents and with any agreed quality assurance and product approval processes that may be needed after the consent is issued.