Section 9.8. Stairs, Ramps, Handrails and Guards
Note: Most local building codes exceed the CNBC. Following CNBC strictly leaves you and your company with a liability should an accident occur. Check with your local building department for any changes that go above and beyond the Canadian National Building Code.
1) This Section applies to the design and construction of interior and exterior stairs, steps, ramps, railings and guards.
220.127.116.11. Exit Stairs
1) Where the stair forms part of an exit, the appropriate requirements in Sections 9.9. and 9.10. shall also apply.
18.104.22.168. Uniform Treads and Risers
1) Treads and risers shall have uniform rise and run in any one flight.
22.214.171.124. Minimum Number of Risers
1) Except for interior stairs within a dwelling unit, at least 3 risers shall be provided for interior stairs.
9.8.3. Stair Dimensions
126.96.36.199. Rise, Run and Tread Depth of Stairs
1) Except as provided in Subsection 9.8.5., the rise, run and tread depth of stairs shall conform to Table 188.8.131.52.
Table 184.108.40.206. Rise, Run and Tread Depth of Stairs
Forming Part of Sentence 220.127.116.11.(1)
|Stair Type||Rise, mm||Run, mm||Tread Depth, mm|
|Service(1)||no limit||125||355||no limit||355||no limit|
Notes to Table 18.104.22.168.:
(1) Service stairs serve areas only used as service rooms or service spaces.
(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 stairs or private stairs.
1) Curved or beveled leading edges of treads
a) shall not reduce the required tread depth by more than 15 mm, and
b) shall not, in any case, exceed 25 mm horizontally.
(See Appendix A.)
22.214.171.124. Stair Width
1) Exit stairs and stairs used by the public shall have a width, measured between wall faces or guards, of not less than 900 mm.
2) At least one stairway between each floor level in a dwelling unit shall have a width between wall faces of not less than 860 mm.
126.96.36.199. Head Room
1) The head room measured vertically from a line drawn through the outer edges of the nosings shall be not less than 1.95 m for stairs located in dwelling units and 2.05 m for all other stairs.
188.8.131.52. Dimensions of Landings
1) Landings shall be at least as wide and as long as the width of stairs in which they occur, except that
b) the length of landing for all other stairs in a straight run need not exceed 1100 mm.
(See also Articles 184.108.40.206. and 220.127.116.11. for landings in exits.)
18.104.22.168. Required Landings
1) Where a door swings towards a stair, the full arc of its swing shall be over a landing.
2) Except as provided in Sentence (3), a landing shall be provided at the top and bottom of each flight of interior stairs and where a doorway occurs in a stairway.
3) Where a door at the top of a stair in a dwelling unit swings away from the stair, no landing is required between the doorway and the stairs.
22.214.171.124. Height between Landings
1) The vertical height between any landings shall not exceed 3.7 m.
126.96.36.199 Height over Landings
1) The clear height over landings shall be not less than 1.95 m in dwelling units and 2.05 m for other landings.
9.8.5. Curved Stairs and Winders
188.8.131.52. Curved Stairs in Exits
1) Curved stairs used in exits shall conform to the requirements of Article 184.108.40.206.
220.127.116.11. Curved Stairs not in Exits
1) Except as permitted in Article 18.104.22.168., a curved stair not required as an exit shall have an average run of not less than 200 mm and a minimum run of 150 mm and shall have risers conforming to Article 22.214.171.124.
126.96.36.199. Required Handrails
1) Except as permitted in Sentences (2) and (3), a handrail shall be provided on
a) at least one side of stairs less than 1100 mm in width,
b) 2 sides of stairs 1 100 mm in width or greater, and
c) 2 sides of a curved stair used as an exit.
188.8.131.52. Continuous Handrail
1) At least one handrail shall be continuous throughout the length of the stairway, including landings, except where interrupted by
a) doorways, or
b) newel posts at changes in direction.
(See A-184.108.40.206.(5) in Appendix A.)
220.127.116.11. Termination of Handrails
1) Handrails shall be terminated in a manner that will not obstruct pedestrian travel or create a hazard. (See Appendix A.)
2) At least one handrail at the sides of a stairway or ramp shall extend horizontally not less than 300 mm beyond the top and bottom of the stairway or ramp. (See A-18.104.22.168.(5) in Appendix A.)
22.214.171.124. Height of Handrails
1) Height of handrails on stairs and ramps shall be measured vertically from a line drawn
a) through the outside edges of the stair nosing, or
b) from the surface of the ramp, floor or landing below the handrail.
2) Except as provided in Sentences (3) and (4), the height of handrails on stairs and ramps shall be
a) not less than 800 mm, and
b) not more than 965 mm.
3) Where guards are required, handrails on landings are permitted to be not more than 1070 mm in height.
4) Handrails not meeting the requirements of Sentences (2) and (3) are permitted provided they are installed in addition to the required handrails.
126.96.36.199. Ergonomic Design
1) A clearance of not less than 40 mm shall be provided between each handrail and the wall to which it is fastened.
2) Required handrails shall be constructed so as to be continually graspable along their entire length with no obstruction on or above them to break a handhold, except where the handrail is interrupted by newels at changes in direction. (See Appendix A.)
188.8.131.52. Projections into Stairway
1) Handrails and constructions below handrails, including handrail supports and stair stringers, shall not project more than 100 mm into the required width of a stairway.
184.108.40.206. Attachment of Handrails
(See Appendix A.)
1) Handrails shall be attached to wood studs, wood blocking, steel studs or masonry at points spaced not more than 1.2 m apart.
2) Attachment to wood studs and blocking required in Sentence (1) shall consist of not less than 2 wood screws at each point, penetrating not less than 32 mm into solid wood.
This information is copied from NationalCodes.ca's website. A-Mezz Industrial Structures is not responsible for the accuracy of this information. This information is meant to serve as guide, not the authority of the Canadian National Building Code. For additional CNBC clarification please visit Canadian National Code's website at www.nationalcodes.ca