To limit the probability that floors and roofs exposed to fire will fail or collapse prematurely during the time required to achieve occupant safety and for emergency responders to perform their duties, which could lead to harm to persons.
To limit the probability that floors and roofs exposed to fire will fail or collapse prematurely, which could lead to the spread of fire from a lower storey of a building to an upper storey or to the exterior of the building during the time required to achieve occupant safety and for emergency responders to perform their duties, which could lead to harm to persons.