The Ontario Building Code | Platforms
3.8.3.17. Platforms
(1) A tactile attention indicator conforming to Article 3.8.3.18. shall be installed along any edge of a platform that is,
(a) not protected by a guard, and
(b) higher than 250 mm above the finished floor or ground or sloped steeper than 1 in 3.
(2) Sentence (1) does not apply to the front edges of stages.
In Plain Language
A tactile attention indicator must be installed along the edge of any unguarded platform higher than 250 mm or sloped steeper than 1-in-3, warning visually-impaired users of the drop-off, though this doesn't apply to stage front edges.
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.