CodeChronicle

OBC 2006 Division B

9.8.4.

Version 0 — in force 31 December 2006

In force
Verified · covered Verified against the 2006-12-31–2007-04-01 consolidation, whose range covers the query date. How to read this

Provenance

New in this edition — no OBC 1997 predecessor

Base · O. Reg. 350/06 · ext← current

Original — base regulation

OBC 2012 · continues as 9.8.4. — Pro

9.8.4. — Step Dimensions

Content not available for this version.

9.8.4.1. — Uniformity and Tolerances for Risers and Treads

(1) Except as provided in Sentence (2), risers shall have uniform height in any one flight with a maximum tolerance of,

(a) 6 mm between adjacent treads or landings, and

(b) 6 mm between the tallest and shortest risers in a flight.

(2) Except for required exit stairs, where the top or bottom riser in a stair adjoins a sloping finished walking surface such as a garage floor, driveway or sidewalk, the height of the riser across the stair shall vary by not more than 1 in 12.

(3) Treads shall have uniform run and tread depth, with a maximum tolerance of,

(a) 6 mm between adjacent treads, and

(b) 6 mm between the deepest and shallowest runs and treads in a flight.

(4) Where angled treads or winders are incorporated into a stair, the treads in all sets of angled treads or winders within a flight shall turn in the same direction.

(5) Cross-slope of treads shall not exceed 1 in 100.

Text · e-Laws consolidated snapshot

9.8.4.2. — Dimensions for Risers

(1) Risers shall conform to Table 9.8.4.2.

Editor's note

In the notes to Table-9.8.4.2., the footnote reference numbers are presented inline with a separating space; the e-Laws consolidation renders them as superscript abutting the text. The footnote text is identical.

Text · e-Laws consolidated snapshot

Table 9.8.4.2. Riser Height, Run and Tread Depth for Rectangular Treads Forming Part of Sentences 9.8.4.2.(1) and 9.8.4.3.(1)

Column 1

Column 2

Column 3

Column 4

Column 5

Column 6

Column 7

Stair Type

All Steps

Rectangular Treads

Rise, mm

Run, mm

Tread Depth, mm

max.

min.

max.

min.

max.

min.

Service and mezzanines in live/work units(1)

no limit

125

355

no limit

355

no limit

Private(2)

200

125

355

210

355

235

Public(3)

200

125

355

230

355

250

Notes to Table 9.8.4.2.:

(1)Service stairs serve areas used only as service rooms or service spaces and stairs that serve mezzanines not exceeding 20 m2 within live/work units.

(2)Private stairs are interior stairs within dwelling units and exterior stairs serving a single dwelling unit.

(3)Public stairs are all stairs not described as service stair or private stairs.

9.8.4.3. — Dimensions for Rectangular Treads

(1) The run and tread depth of rectangular treads shall conform to Table 9.8.4.2.

(2) The depth of a rectangular tread shall be not less than its run and not more that its run plus 25 mm.

Text · e-Laws consolidated snapshot

9.8.4.4. — Dimensions for Angled Treads

(1) Angled treads in required exit stairs shall comply with Article 3.4.6.8.

(2) Except as provided in Article 9.8.4.5., angled treads in other than required exit stairs shall have an average run of not less than 200 mm and a minimum run of 150 mm.

(3) The depth of an angled tread shall be not less than its run at any point and not more than its run plus 25 mm.

Text · e-Laws consolidated snapshot

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.

Text · e-Laws consolidated snapshot

9.8.4.6. — Leading Edges of Treads

(1) Leading edges of treads that are bevelled or rounded shall,

(a) not reduce the required tread depth by more than 15 mm, and

(b) not, in any case, exceed 25 mm horizontally.

Text · e-Laws consolidated snapshot

9.8.4.7. — Interior Stairs Extending Through the Roof

(1) Interior stairways extending through the roof of a building shall be protected from ice and snow.

Text · e-Laws consolidated snapshot