The Ontario Building Code | Protection of Structural Steel Members
9.10.7.1. Protection of Structural Steel Members
(1) Except as provided in Article 3.2.2.3., structural steel members used in construction required to have a fire-resistance rating shall be protected to provide the required fire-resistance rating.
9.10.8. Fire-Resistance, Combustibility and Sprinklers in Relation to Occupancy, Height and supported Elements