Stairs are not the recommended means of negotiating changes in level because they represent a barrier for many, but particularly for people who use wheeled mobility aids. The barriers imposed by stairs go beyond the obvious physical restriction for wheelchair users. They represent a psychological barrier for some and a symbol of exclusion, as well as a safety risk for others. As such, the use of stairs is not recommended as part of an exterior path of travel, but only as an alternate means of negotiating level changes where wheelchair access is already provided.
The requirements for stairs are intended to improve safety and accessibility for all stair users, including people with disabilities. Stairs may not be an option for people using wheeled mobility aids, but they will be used by many people with different types of disabilities and all other users of the facility. In some instances, a person with a disability may prefer to climb a short set of stairs instead of using a long and circuitous ramp.
The safety and usability of stairs will depend on key technical requirements such as the dimension of each step, the use of tactile walking surface indicators, and the appropriate design of handrails and guards.
Handrails are a key element in the usability and safety of stairs. They provide a secure handhold and are especially important for those with stamina issues or poor balance. They also provide an important orientation cue. Horizontal extensions at the tops of stairs give notice of an upcoming step and offer stability before using it. Horizontal extensions at the base of stairs provide notice to the user that they have reached the last step and, in some cases, guide users around a landing to the next set of stairs.
The shape of the rail, mounting height and continuity are key components for the usability of handrails.
The requirements of this section apply to newly constructed and redeveloped stairs within general site boundaries of buildings and in a range of public settings such as parks and along municipal sidewalks. These rules do not apply to stairs within buildings or along exterior barrier-free routes regulated by Ontario’s Building Code, such as along routes within a site to barrier-free entrances, passenger loading zones and parking lots with barrier-free parking.
Requirements for the Design of Stairs
- Surface of treads
- Must be slip resistant.
- Rise and run
- Uniform in any one flight.
- Rise dimensions (between successive treads)
- Must be between 125 mm - 180 mm.
- Riser configuration
- Must have closed risers.
- Run dimensions(between successive steps)
- Must be between 280 mm - 355 mm.
- Nosing projection
- Maximum 38 mm, with no abrupt undersides
- High tonal contrast markings that extend the full tread-width of each step.
- Provide handrails on both sides of ramps, including at landings, and ensure they:
- Are continuously graspable along the entire length.
- Have cross-section with an outside diameter of between 30 mm and 40 mm if they are circular. Non-circular shapes must have a graspable portion with a perimeter between 100 mm and 155 mm and a diameter not more than 57 mm.
- Are between 865 mm and 965 mm high, measured vertically from a line drawn through the outside edges of the stair nosings, or the surface of landings. Handrails that do not meet these requirements are allowed if they are installed in addition to the required handrail.
- Terminate in a way that will not obstruct pedestrian travel or create a hazard.
- Extend horizontally 300 mm, at minimum, beyond the top and bottom of the stairs.
- Have a clearance of 50 mm, at minimum, from any wall to which they are attached.
- Will withstand the loading values obtained from the non-concurrent application of a concentrated load not less than 0.9 kN applied at any point and in any direction and a uniform load not less than 0.7 kN/metre applied in any direction to the handrail.
Provide intermediate handrails where a ramp is wider than 2,200 mm. These handrails must be continuous between landings, located so that there is no more than 1,650 mm between handrails and meet the requirements for handrails listed above.
- Tactile walking surface indicators (TWSIs)
- Location: TWSIs must be provided at the top of all flights of stairs.
- Size: TWSIs must be at least 610 mm in depth and extend the full width of the stair, starting one tread depth from the leading edge of the top step.
- Profile: TWSIs must have their tactile elements raised above the adjacent ground surface.
- Tonal contrast: High tonal contrast must be used to differentiate the TWSIs from the adjacent ground surface.
- Location: Guards must be provided on each side of a stairway where the difference in elevation between ground level and the top of the stair is more than 600 mm. Guards are not required where there is an adjacent wall or other barrier on that side.
- Height: Minimum 920 mm, measured vertically to the top of the guard from a line drawn through the outside edges of the stair nosings. Guards shall be minimum 1,070 mm around landings.
Better Practice Considerations
- Clear width
- Consider a minimum clear width of 900 mm to provide more space for people to pass each other. Widths of more than 1,200 mm will prevent the use of both handrails at the same time, which would make it difficult for some people with disabilities to use the stairs.
- Nosing top-surface tonal contrast
- To enhance the definition of the edge of steps, consider a difference of at least 70% between the light reflectance value (LRV) of the nosing surface and the adjacent tread surface. Refer to Figure 184.108.40.206 for further details on measuring LRV.
- Height: Providing a second, lower handrail 600 mm - 750 mm above the outside edges of the stair nosings, or the surface of landings will enhance usability and safety for children, and other people of small stature.
- Shape: Consider providing round handrails as they are easier to grasp.
- Tonal contrast: Handrails that contrast in tone to the surface they are mounted on will be more visible to all users and particularly helpful for people with low vision.
- Adjacent wall or surface: Consider providing at least 70 mm of clearance to rough or abrasive surfaces, to protect users’ knuckles, particularly people with lager hands.
- Objects above a handrail: Consider at least 450 mm of clearance to objects that are above a handrail, to provide sufficient space to comfortably accommodate users’ forearms.
- Tactile walking surface indicators (TWSIs)
- Size: Consider making TWSIs at least 920 mm in depth, extending the full width of the stair, starting one tread depth from the leading edge of the top step. A deeper TWSI provides an earlier warning on the proximity of the top of the stair.
- Profile: Consider a truncated-dome type tactile attention indicator surface as indicated in CSA B651-12 - Accessible design for the built environment. Refer to Appendix F - CSA Standards for Tactile Warning Surface Indicators. Truncated-dome type TWSIs are widely recognized as a ‘stop’ signal to pedestrians. Other TWSI configurations may not be as effective in providing the ‘stop’ message.
- Tonal contrast: To enhance the definition of the TWSI, consider a difference of at least 70% between the light reflectance value (LRV) of the TWSI surface and the adjacent ground/floor surface. Refer to page 53 for further details on measuring LRV.
- Stair treads that are perpendicular to the direction of travel are safer for everyone to use.
- Avoid curved stairs if possible, as they are more challenging to negotiate.
- Where stairs are open below and adjacent to a pedestrian route, consider providing a railing or other barrier to prevent people from walking into areas where the clear height is lower than 2300 mm.