Passive Fire Protection – What is it, and why is it so important?

Passive fire protection is a crucial element of fire protection that should be planned for from the very initial design stages of any new building – and retrofitted where possible into all existing building fit-outs.

Passive fire protection saves lives & property

Construction elements in a building can be used to prevent, or delay, fire and smoke spreading through the building using physical barriers and fire cells to create passive fire protection.

To be effective, architects should plan for passive fire protection from the initial design stages of any building project, as can contribute hugely to the fire safety of any building. Of course passive fire protection should be complemented by the use of fire alarms, sprinkler systems, fire evacuation plans and great safety training – but implementing passive fire protection can greatly reduce the danger to people and property in a fire emergency. 

These illustrations show various forms of passive fire protection. Each form of passive fire protection is designed to provide smoke separation as well as fire resistance.

 

From BRANZ, adapted from AS 18512012 Routine service of fire protection systems and equipment.

 

Note that passive fire protection must be supported by good fire safety management, including sprinklers, fire alarms, ensuring that fire protection is available at all times, planning for an facilitating escape in the event of fire and preventing fire damage to nearby buildings.

How passive fire protection works

Passive fire protection is designed to act as physical barriers that contain fire and smoke and limit fire, and to protect crucial structural components from fire to delay or prevent structural collapse. To do this, flammability and fire resistance of the building’s construction materials need to be controlled and carefully planned during design. 

Passive fire protection has two key components:

  • Fire resistance – focused on using a fire-separating element (a wall, floor or ceiling) to limit the spread of fire through the element, or to prevent structural collapse of load-bearing elements 

  • Reaction to fire – restricting flammability (surface burning behaviour of an element or material and how it promotes rapid flame spread, hot gases or smoke production).

Passive fire protection provides protection simply by being there

Passive fire protection is an important part of building fire safety and should be subject to the same rigorous installation documentation, inspection and sign-off as active fire protection. Passive fire protection systems should be correctly specified, installed and maintained. 

Passive fire protection through separation of fire cells

Dividing building construction into firecells with fire resistant materials can help prevent smoke and fire spread, and contain fire for a specified period of time. 

This diagram from BRANZ illustrates the concept of total separation.

 

New Zealand is not employing Passive Fire Protection effectively

BRANZ state that:

“Considerable evidence exists to show that, in a large proportion of buildings, passive fire protection is not being effectively designed, specified and delivered 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.”

To this end they have created this useful Guide to Passive Fire Protection which describes good practice for the specification, approval, installation and verification of passive fire protection, and identifies the requirements of the New Zealand Building Code (NZBC).

If you have any questions about Fire Safety in your building or new construction, contact us and we’ll point you in the right direction!