Code Library › Volume 1 › Section 3.3 — Safety Within Floor Areas (See Note A-3.3.)
PART 3 — FIRE PROTECTION, OCCUPANT SAFETY AND ACCESSIBILITYUpdated for the 2024 Ontario Building Code

3.3.1.16.Tapered Treads in a Curved Flight

(1) Flights of stairs shall consist solely of (a) straight flights, or (b) curved flights complying with Sentence (2). (2) Tapered treads in a curved flight that is not required as an exit shall have (a) a minimum run of 150 mm, (b) a run not less than 280 mm when measured at a point 300 mm from the centre line of the handrail at the narrow end of the tread, and (c) a riser conforming to Sentence 3.4.6.8.(2). (3) Tapered treads shall have a consistent angle and uniform run and rise dimensions in accordance with the construction tolerances described in Article 3.4.6.8. when measured at a point 300 mm from the centre line of the handrail at the narrow end of the tread. (4) All tapered treads within a flight shall turn in the same direction.
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Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.