Fire Safety by Design
Fire safety in buildings has two components: active systems (sprinklers, alarms, extinguishers — systems that detect and respond to fire) and passive systems (the building’s structural and architectural elements that limit fire spread by containing it within defined compartments). Passive fire protection is built into the fabric of the building and works without any activation — it’s the fire-rated walls, floors, and doors that buy time for evacuation and limit the extent of fire damage.
For builders, passive fire protection requirements are embedded in building consents and need to be achieved during construction. Getting it wrong — by penetrating fire-rated elements without proper stopping, or by installing fire doors incorrectly — can invalidate the fire rating of an element and undermine the building’s life safety performance in a fire.
Fire-Rated Elements
Buildings are divided into fire compartments by fire-rated walls, floors, and doors. The fire resistance rating (FRR) of these elements — expressed in minutes for structural adequacy, integrity, and insulation — is specified in the building consent documentation and must be achieved by the construction as built. Common fire-rated assemblies include: 60/60/60 fire-rated wall systems using specific lining systems on steel or timber framing; fire-rated concrete or masonry walls and floors; and fire-rated door assemblies including frames, doors, seals, and hardware.
Firestopping Penetrations
Every penetration through a fire-rated element — for pipes, ducts, cables, and conduits — creates a potential path for fire to spread between compartments unless the penetration is correctly stopped. Firestopping products — intumescent collars for plastic pipes, fire-rated pillows for cable bundles, intumescent mastic for gap sealing — are required at every such penetration, installed in accordance with the manufacturer’s requirements for the specific combination of element rating and penetration type.
Documentation
Passive fire protection requires careful documentation — both to demonstrate to the building consent authority what was done, and to provide the building owner and future maintainers with the information they need to maintain the fire rating. As-built documentation showing the location and specification of all fire-rated elements and firestopping details is a professional standard that protects everyone involved.