FS 03 Fire bolts in fire doors

Purpose

This practice note provides clear advice and guidance on fire bolts. This includes providing information to support the industry moving forward, to understand:

• What fire bolts are.
• How they are incorporated in the fire door system.
• Whether fire bolts in fire doors comply with the Building Act 1993 (the Act), the Building Regulations 2018 (the Regulations) and the National Construction Code - Building Code of Australia (BCA).
• How they can be used in new and existing buildings.

What are Fire Bolts?

Fire bolts, also referred to as heat-activating, thermal or fire pins, are devices which are typically recessed into the door leaf and activate during exposure to temperature, as a result, fixing and securing the fire door leaf to the frame.

Fire bolts are used to help meet the Fire Resistance Level (FRL) criteria in the BCA and in accordance with AS 1530.4 – 2014, Methods for Fire Tests on Building Materials, Components and Structures – Part 4: Fire-Resistance Test of Elements of Construction.

Figure 1: Fire Bolt

Image produced by BPC

Risk associated with the use of fire doors fitted with Fire Bolts

The main risks associated with fire doors fitted with fire bolts relate to:

• occupant and fire brigade personnel safety, following the activation of fire bolts
• the ability for the fire brigade to undertake search and rescue and firefighting operations
• operation of doors following the activation of fire bolts.

Fire bolts can obstruct fire door functionality from either:

• preventing the closure of a fire door where the fire bolts operate whilst the door is open
• preventing the door from opening, where the fire bolts operate whilst the door is closed.

Unclear standards may increase safety risks

In Australia, there is no defined standard of construction, testing, manufacture or maintenance for fire bolts in fire doors. This leads to uncertainty around the performance of fire bolts in doors, as there are no clear design guidelines or understanding about what can be expected from these devices.

Whilst these devices are generally understood to activate at temperatures above 200 degrees Celsius, this is not definitive as there is no adopted standard for their design or use.

As fire bolts are often located at the upper part of the door, the risk of occupant entrapment can be high, where bolts could be activated by the hot smoke layer whilst occupants are still evacuating within a tenable egress route.

Building Regulations 2018

Regulation 228 of the Regulations requires the maintenance of exits and paths of travel in certain buildings. This regulation requires that all exits and paths of travel to exits in buildings are kept readily accessible, functional and clear of obstructions so that egress from the building is maintained. Therefore, the requirement of Regulation 228 cannot be met when the use of fire doors fitted with fire bolts have not been justified via a performance solution or a Building Appeals Board (BAB) determination.

Ethics and conduct

Principle 1 of the Code of Conduct for Building Surveyors requires building surveyors to act in accordance with the law and in the public interest. Where there is doubt as to the interpretation of legislation, the BCA or standards, building surveyors are required to prefer the interpretation that best serves the objectives of the Act and the public interest. The objective of Section 4(1)(a) of the Act is to protect the safety and health of people who use buildings.

When interpreting the BCA with respect to fire doors fitted with fire bolts, the interpretation that best serves the objectives of the Act is to conclude that they do not comply with Clause D3D26 of the BCA.

Builders, building designers, architects and engineers must be cognisant of any Code of Conduct and statutory professional conduct obligation that applies to their profession.

BCA compliance

Fire doors must comply with several relevant BCA Performance Requirements, including those in Sections C, D and E, when they are installed in:

• an exit
• forming part of an exit
• in the path of travel to an exit.

Where the DtS Provisions of the BCA requires a FRL, A5G5 of the BCA mandates that this is determined in accordance with Specifications 1 and 2. For a door that requires a FRL, this is a prototype that has been submitted to AS 1530.4 and is confirmed in a report from an Accredited Testing Laboratory (ATL). Whilst this may satisfy some requirements of Section C of the BCA in isolation, there are other requirements that are relevant and need to be considered.

The DtS Provisions of Clause D3D26 of the BCA are not met when using fire doors fitted with fire bolts. Therefore their use must be approved via a Performance Solution or subject to a BAB determination. Any Performance Solution must address all relevant Performance Requirements.