What is passive fire protection?
Passive fire protection systems are designed to contain flames in certain parts of a building. This prevents the spread of flames from room to room and floor to floor. Just as importantly, passive protection stops smoke and other toxins from spreading throughout the building, which can be just as damaging as fire. Despite the name passive, these systems are always there and always ready, being built into the very structure and fixtures of a building.
The basic way that passive fire protection systems work is by eliminating gaps and installing firestops at any locations where fire might be able to spread or cause significant damage. This could be a design decision (e.g. not using flammable materials such as wood in certain areas), or the installation of a specific piece of equipment that seals a gap.
In an interview with Buildings, Chris Jelenewicz, engineering program manager at Society of Fire Protection Engineers (SFPE) outlined four key areas to consider with a passive system:
1. Structural fire protection: Protects key structural components such as steel and joint systems. It is typically achieved by fireproofing with a substance that is flame retardant, such as concrete.
2. Compartmentalisation: Barriers that prevent the spread of flames. These partitions can include everything from fire-rated walls through to dedicated smoke and flame barriers.
3. Opening protection: Apertures such as doors, windows or air ducts that can compromise a fire barrier need to be strong enough to withstand flames. For example, special glazing on any pieces of glass.
4. Firestopping: Perhaps the greatest risk in terms of a fire spreading is small flaws, or penetrations in a fire barrier. These may have been left by a contractor such as an electrician or plumber, and if not protected with a passive firestop product, these gaps can undermine the entire system.