Passive vs active: two halves of fire safety
Active fire protection acts when a fire starts: detectors, alarms, sprinklers, hydrants, extinguishers. Passive fire protection is already in place before ignition — it is the building itself, constructed to contain fire rather than fight it.
| Active | Passive | |
|---|---|---|
| Examples | Detection, alarms, sprinklers, hydrants | Rated walls and floors, fire doors, fire-stopping, dampers |
| Works by | Activating on fire | Being built correctly |
| Fails by | Not operating | Being breached and never resealed |
Most facility attention (and budget) goes to the active side, because it is visible and serviceable. Audits, however, fail buildings on the passive side — because breaches are silent and accumulate for years.
Compartmentation, in one paragraph
The National Building Code treats a building as a set of fire compartments: volumes bounded by walls, floors and doors of a stated fire-resistance rating, designed to hold fire and smoke for that rated duration. Stairwells, shafts, electrical rooms and each floor plate are typically separate compartments. Every element on a compartment boundary — including the humble door closer — is part of the rating.
Why fit-outs are where compartmentation dies
Every fit-out routes new services — cables, data trays, pipes, ducts — through rated walls and floors. The contractor cuts the opening, pulls the service, and moves on. Unless each opening is resealed with a rated firestop system matched to the service type and wall construction, the compartment now leaks smoke and fire at that point.
Multiply that by every fit-out, re-cabling and repair in a building’s life, and a “two-hour wall” can hold dozens of unsealed penetrations. None of them show on a walkthrough; all of them show to smoke.
What a fire auditor actually checks
- Service penetrations above false ceilings, in shafts and behind risers — sealed with rated material, or stuffed with foam and cloth?
- Fire doors — do they close, latch and seal? Are gaps within the door’s rating? Are closers and hardware intact?
- Compartment drawings — does anyone know where the rated lines run?
- Documentation — evidence of what was remediated, with what material, where.
How remediation should be documented
Credible passive-fire work is documented compartment by compartment: each breach photographed before and after, the rated firestop system named, and the location mapped on a plan. That file is what turns a remediation invoice into audit evidence — an auditor can spot-check any entry on site and find the seal where the file says it is.