(1) Except as provided in Sentences (2) and (3), public corridors shall be separated from the remainder of the building by a fire separation having not less than a 45 min fire-resistance rating.
(2) In other than residential occupancies, no fire-resistance rating is required for fire separations between a public corridor and the remainder of the building if,
(a) the floor area is sprinklered,
(b) the sprinkler system is electrically supervised in conformance with Sentence 3.2.4.10. (3), and
(c) the operation of the sprinkler system will cause a signal to be transmitted to the fire department in conformance with Sentence 3.2.4.8. (4).
(3) In other than residential occupancies, no fire separation is required between a public corridor and the remainder of the building if,
(a) the floor area is sprinklered,
(b) the sprinkler system is electrically supervised in conformance with Sentence 3.2.4.10. (3),
(c) the operation of the sprinkler system will cause a signal to be transmitted to the fire department in conformance with Sentence 3.2.4.8. (4), and
(d) the corridor exceeds 5 m in width.