9.8.9.

(1) Except as required in Articles 9.8.9.4. and 9.8.9.5., stairs and ramps shall be designed for strength and rigidity under uniform loading criteria to support specified loads of,

(a) 1.9 kPa for stairs and ramps serving a single dwelling unit, and

(b) 4.8 kPa for other stairs and ramps.

(1) Exterior concrete stairs with more than 2 risers and 2 treads shall be,

(a) supported on unit masonry or concrete walls or piers not less than 150 mm in cross section, or

(b) cantilevered from the main foundation wall.

(2) Stairs described in Sentence (1), when cantilevered from the foundation wall, shall be constructed and installed in conformance with Subsection 9.8.10.

(3) The depth below ground level for foundations for exterior steps shall conform to the requirements in Section 9.12.

(1) Exterior wood steps shall not be in direct contact with the ground unless suitably treated with a wood preservative.

(1) Wooden stair stringers shall,

(a) have a minimum effective depth of 90 mm, measured perpendicularly to the bottom of the stringer at the point of minimum cross-section, and an over-all depth of not less than 235 mm,

(b) be supported and secured top and bottom,

(c) be not less than 25 mm actual thickness if supported along their length and 38 mm actual thickness if unsupported along their length, and

(d) except as permitted in Sentence (2), be spaced not more than 900 mm o.c. for stairs serving not more than one dwelling unit, and 600 mm o.c. in other stairs.

(2) For stairs serving not more than one dwelling unit where risers support the front portion of the tread, the space between stringers shall be not more than 1 200 mm.

(1) Stair treads of lumber, plywood or O-2 grade OSB within dwelling units shall be not less than 25 mm actual thickness, except that if open risers are used and the distance between stringers exceeds 750 mm, the treads shall be not less than 38 mm actual thickness.

(2) Stair treads of plywood or OSB, that are not continuously supported by the riser shall have their face grain or direction of face orientation at right angles to the stringers.

(1) Except as required in Sentence (4), the finish for treads, landings and ramps shall be,

(a) wear resistant,

(b) slip resistant, and

(c) smooth, even, and free from open defects.

(2) The finish for treads and landings of interior stairs in dwelling units, including those from an attached garage serving a single dwelling unit, shall be deemed to comply with Sentence (1) where these treads, landings, or ramps are finished with,

(a) hardwood,

(b) vertical grain softwood,

(c) resilient flooring,

(d) low-pile carpet,

(e) mat finish ceramic tile,

(f) concrete, or

(g) for stairs to unfinished basements and to garages, plywood.

(3) Stairs and ramps, except those serving a single dwelling unit or service rooms or spaces, shall have either a colour contrast or a distinctive pattern to demarcate,

(a) the leading edge of the treads,

(b) the leading edge of the landing, and

(c) the beginning and end of a ramp.

(4) Treads and landings of interior and exterior stairs and ramps, other than those within dwelling units, shall have a slip-resistant finish or be provided with slip-resistant strips that extend not more than 1 mm above the surface.