BCAB #1686 - Stair Winder or Landing, Sentences 3.3.1.14.(1), 3.3.1.16.(1), 3.4.6.3.(2), 3.4.6.7.(2) & 3.4.6.8.(2)

December 16, 2010

BCAB #1686

Re: Stair Winder or Landing, Sentences 3.3.1.14.(1), 3.3.1.16.(1), 3.4.6.3.(2), 3.4.6.7.(2) & 3.4.6.8.(2)

Project Description
This appeal concerns two identical stairs in the lobbies of two adjacent Part 3 buildings. The stairs have two straight runs separated by an irregular tread/winder/landing about 1/3 of the way up from the bottom which turns through an angle of 30 degrees. The minimum run is the same as the adjacent treads (305 mm). These are not exit stairs and only provide access between the first and second storeys.

Reason for Appeal
Sentence 3.3.1.14.(1) requires stairs not forming part of an exit to, in part, conform to the dimensional requirements of Articles 3.4.6.1.to 3.4.6.8.

Appellant’s Position
The appellant contends that this is a tapered tread or winder and the Code does not preclude the incorporation of such treads in a stair not used as part of an exit. The tread in question does substantially conform to the dimensional restrictions for curved stairs permitted in an exit even though it is not strictly speaking a curved stair.

Building Official's Position
The building official maintains that Sentence 3.4.6.7.(2) requires a uniform run in any given flight and Sentence 3.4.6.3.(2) requires a landing to be at least 1100 mm long (run). Not being a curved stair there are no other provisions in Part 3 that permit a change in direction using a single tapered tread or winder.

Appeal Board Decision #1686
It is the determination of the Board that the irregular component of the stairs creates a non-uniform run in contravention of Sentence 3.4.6.7.(2) and it does not conform to the dimensional requirements for landings in Sentence 3.4.6.3.(2). The Board does not consider the design to be a curved stair so the provisions of Article 3.4.6.8. do not apply and there are no provisions for winders in Part 3. Therefore, the stairs do not conform to the provisions of the Code.

George Humphrey, Chair