For a high-rise building with no fire sprinklers, what is the required fire-resistance rating of the fire barriers enclosing vertical shafts?

In a high-rise building without fire sprinklers, building codes and fire safety regulations mandate that fire barriers enclosing vertical shafts, such as stairwells and elevator shafts, must have a fire-resistance rating of 2 hours. This requirement is crucial because these vertical shafts can act as chimneys, allowing fire and smoke to spread vertically throughout the building, which poses a significant risk to the safety of occupants.

A 2-hour fire-resistance rating ensures that these barriers are capable of withstanding fire exposure for that duration, providing critical time for occupants to evacuate safely and for fire services to respond. Furthermore, a properly rated fire barrier can help contain flames and smoke, preventing them from penetrating other floors and compartments of the building.

While other ratings like 1 hour, 3 hours, or 4 hours may apply in different contexts or building configurations, the specific requirement for a high-rise structure without sprinklers falls at the 2-hour level to effectively mitigate fire risks associated with vertical transmission. This standard is aligned with national building codes aimed at preserving life safety and property protection in larger structures.