Passive Fire Protection

Passive fire protection is the fabric of the building that contains fire and smoke and keeps the structure standing long enough for people to escape and fire-fighters to work: fire-resisting walls, floors and ceilings that divide the building into compartments; fire doors and their hardware; fire-resisting glazing; protection of penetrations where services pass through; cavity barriers and fire stopping in concealed spaces; and fire protection of the structure itself. It does nothing until a fire, and it is broken every time a building is altered.

A building's passive fire protection is defined by its fire strategy or fire engineering report, which sets the compartments, fire-resistance levels and escape routes. Without that document, nobody knows which walls and doors matter. Many older buildings have no current strategy, and many performance solutions rely on passive elements that later works have undone.

What shortens life:

• Alterations: every cable, pipe and duct installed after construction is a potential breach.
• Fit-outs that move walls, add doors and remove ceilings.
• Daily use: doors wedged open, closers disconnected, seals damaged by trolleys.
• Maintenance by trades who do not know which elements are fire-rated.
• Water on spray-applied and intumescent protection.

Breached penetrations

The most common passive fire defect in existing buildings is an unsealed or improperly sealed penetration: cables pushed through holes in fire walls, pipes surrounded by expanding foam that is not fire-rated, ducts without dampers, holes left after services were removed. Risers, plant rooms and ceiling voids above corridors are the worst areas. Each breach lets fire and smoke move between compartments.

Walls not built to the slab

Fire-resisting walls must run from floor slab to floor slab or to a fire-rated ceiling. Walls that stop at the suspended ceiling, or that had their top sections removed for services, leave a path for fire over the top. This is often found only by lifting ceiling tiles.

Fire door failures

Fire doors fail through use: closers disconnected or broken so doors do not close; doors wedged or propped open; gaps at edges larger than allowed; intumescent and smoke seals painted over, damaged or missing; non-rated hinges, locks and vision panels; doors cut down to clear new floor finishes; and, in apartment buildings, flat entrance doors replaced by residents with non-rated doors. A fire door that does not close fully is not a fire door.

Glazing replacements

Broken fire-resisting glazing replaced with ordinary glass, or beads and frames replaced with untested parts, loses its fire resistance entirely.

Missing cavity barriers

Concealed spaces in walls, floors, roofs and façades need barriers to stop fire travelling unseen. Missing or misplaced cavity barriers in façades and in timber-framed construction have allowed fire to spread rapidly through buildings.

Damaged structural protection

Spray-applied fire protection on steel is knocked off by later trades, fixings and services; intumescent coatings are chipped, overpainted with incompatible paint, or weathered where exposed. Unprotected steel loses strength quickly in fire.

Unverified products and certification

Fire stopping and door products must be installed as tested. Untested combinations, products used outside their tested range, and missing certification leave the protection unproven. Older protection may contain asbestos.

In the building

• Holes and unsealed gaps around services in risers, plant rooms and above ceilings.
• Expanding foam around pipes and cables in fire walls.
• Fire doors propped or wedged open; closers disconnected; doors not closing fully into the frame.
• Gaps at door edges; seals painted, damaged or missing; non-rated hardware.
• Fire door labels or tags missing or illegible.
• Ordinary glass in fire-resisting screens and doors.
• Walls stopping at the ceiling line when tiles are lifted.
• Damaged spray protection on steel; chipped intumescent coatings.

In the records

• Fire strategy or fire engineering report, including performance solutions.
• Compartmentation drawings.
• Fire door register and inspection records.
• Fire stopping records, with photographs and product details.
• Annual fire safety statements or essential safety measures reports.
• Asbestos register.

Findings are graded by what they demand: safety (can hurt someone now), failure (failed and damaging the building), condition (distress present and progressing), lifecycle (renewal due on age and exposure), deadline (a regulator or ordinance sets the date), check (investigate before sizing works) and nil (cosmetic or stable).

A fire engineer or passive fire specialist leads, working from the fire strategy; where there is no strategy, the investigation begins by establishing one.

• Strategy review: compartments, fire-resistance levels, escape routes and performance solutions.
• Compartmentation survey above ceilings, in risers and plant rooms, recording every penetration and its seal, with photographs.
• Fire door survey of every door on escape routes and compartment lines, including all flat entrance doors in residential buildings: closing, gaps, seals, hardware, glazing, labels.
• Structural protection survey of exposed and concealed steel.
• Product identification against tested systems and certification.
• Asbestos sampling of older protection.

The report should give a register of defects by location with photographs, prioritised by risk, and the strategy those defects affect.

• Escape route check: door closing, glazing and wall integrity on every stair and protected corridor.

• Fire stopping of every breach with tested systems, recorded with photographs and product data.
• Fire door repair: closers, seals, hardware, adjustment; replacement of doors that cannot be repaired; certified doorsets for flat entrances.
• Hold-open devices linked to the fire alarm where doors need to stay open in use.
• Wall completion to slab where walls stop at the ceiling.
• Glazing replacement with tested fire-resisting glass and frames.
• Structural protection repair with compatible products.
• Fire strategy update and compartmentation drawings.
• Management: permits for works that penetrate fire-rated elements, and regular door checks.

• Labelling: identify fire-resisting walls above ceilings and in risers so trades know what they are penetrating.

Surveys are lump sums. Fire stopping is priced per penetration or per riser floor. Door repair and replacement per door. Structural protection repair by area. Fire strategy preparation is a lump sum. Access above ceilings and in risers, and work in occupied buildings, drive cost.

Safety rectification and certification are code compliance; door and hardware replacement is lifecycle; ongoing door checks are repairs and maintenance.

Fire door surveys of whole apartment buildings are lump sums priced per door.

• Australia. The National Construction Code sets fire-resistance levels and compartmentation; AS 1530.4 sets fire-resistance testing, AS 4072.1 penetration seals, AS 1905.1 fire doors; AS 1851 sets fire door inspection; passive elements are essential safety measures with annual certification; AS 4655 covers fire safety audits.
• United Kingdom. Approved Document B sets requirements; the Fire Safety (England) Regulations 2022 require quarterly checks of communal fire doors and annual best-endeavour checks of flat entrance doors in residential buildings over 11 metres; the Fire Safety Act 2021 brings flat entrance doors and external walls into the responsible person's duties; BS 8214 covers fire doors.
• United States. International Building Code Chapter 7 governs fire-resistance-rated construction; NFPA 80 requires annual inspection of fire doors, and NFPA 105 smoke doors; firestop systems are tested to ASTM E814 and UL 1479.

• Fire strategy or fire engineering report, including performance solutions.
• Compartmentation drawings.
• Fire door register and inspection records.
• Fire stopping records with photographs.
• Annual fire safety statements or essential safety measures reports.
• Asbestos register.
• Permits for works that penetrated fire-rated elements.

• Fire door certification for replaced doors.
• Records of resident door replacements in apartment buildings.