Sentence 9.10.9.15.(4)

Intent 1:

To exempt public corridor separations from the application of Sentence 9.10.9.15.(1) by waiving the requirement for a minimum 45 min fire-resistance rating, if certain conditions are met [i.e. smoke-tight barrier of not less than 12.7 mm gypsum board is installed on both sides of walls and on the underside of floor-ceiling framing separating the corridor from the remainder of the building], on the basis that construction of rated fire separations may be cost-prohibitive and the reduction in protection from spread of fire is offset by more stringent requirements for notification of occupants.

Intent 2:

To limit the probability that fire or smoke will spread into a public corridor, or from a public corridor into the remainder of the building, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.

Intent 3:

To limit the probability that fire or smoke will spread into a public corridor, which could lead to delays or ineffectiveness in fire emergency response operations, which could lead to:

• delays in the evacuation or movement of persons to a safe place, or
• the spread of fire to other parts of the building.

This is to limit the probability of harm to persons.