The Ontario Building Code | Winders
9.8.4.5. Winders
(1) Stairs within dwelling units are permitted to contain winders that converge to a centre point provided,
(a) the winders turn through an angle of not more than 90°,
(b) individual treads turn through an angle of not less than 30° or not more than 45°, and
(c) adjacent winders turn through the same angle.
(2) Where more than one set of winders described in Sentence (1) is provided in a single stairway between adjacent floor levels, such winders shall be separated in plan by at least 1 200 mm.
In Plain Language
Winders, pie-shaped steps used to turn a stairway's direction, have their own specific design requirements set out in this article.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.