Code Library › Volume 1 › Section 3.4 — Exits
PART 3 — FIRE PROTECTION, OCCUPANT SAFETY AND ACCESSIBILITYUpdated for the 2024 Ontario Building Code

3.4.6.9.Curved Flights in Exits

(1) Exit stair flights shall consist solely of (a) straight flights, or (b) curved flights complying with Sentence (2). (2) A curved flight used as an exit shall have (a) a handrail on each side, (b) a minimum run of 240 mm, (c) treads with a run that conforms to Article 3.4.6.8. when measured at a point 300 mm from the centre line of the inside handrail at the narrow end of the tread, and (d) an inside radius that is not less than twice the stair width. (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.
← Previous3.4.6.8. Treads and Risers (See Note A-9.8.4.)Next →3.4.6.10. Horizontal Exits

Common questions about this part of the code

When are two exits required from a floor area in Ontario?How is required exit width calculated under the Ontario Building Code?How many exits does a floor area need under the Ontario Building Code?How far apart must exits be located under the Ontario Building Code?

Understand this provision in seconds

BUILDAiD Assist explains any article of the building code in plain English — with exact citations, exceptions and related requirements.

Try BUILDAiD Beta

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.