The Ontario Building Code | Fire-Resistance Ratings in Sprinklered Buildings
9.10.8.2. Fire-Resistance Ratings in Sprinklered buildings
(1) Except for roofs that support an occupancy, the requirements in Table 9.10.8.1. for roof assemblies to have a fire-resistance rating are permitted to be waived in sprinklered buildings where,
(a) the sprinkler system is electrically supervised in conformance with Sentence 3.2.4.10.(3), and
(b) 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).