What is the third unit of defense in fire and life safety?

The third unit of defense in fire and life safety is indeed the floor assembly. In healthcare construction and facility management, fire and life safety design is typically structured around a tiered approach to protect occupants and property from fire hazards. This approach includes multiple layers or units of defense, which help to contain fires, provide safe egress paths, and uphold the integrity of the building during a fire event.

The floor assembly acts as a critical component in this defense strategy, as it can help prevent the vertical spread of smoke and fire within a building. It also serves to protect the structural integrity of the building and can be designed to provide adequate fire resistance ratings to ensure safe evacuation and allow for effective firefighting operations. By effectively compartmentalizing spaces, the floor assembly can limit fire spread between different areas, offering a refuge for occupants until they can safely exit the building.

In this context, while the roof structure, wall assembly, and fire exits also play vital roles in overall fire safety, the floor assembly is specifically aligned with the concept of containing fires and protecting lives as part of a multi-tiered approach. This distinction clarifies why the floor assembly is recognized as the third line of defense in fire safety protocols.