On Friday, February 26, 2021, OHBA hosted a technical committee meeting that featured a presentation by Michael Lio of buildABILITY: "Guidance for the OBC 2022 Requirements for Stairs, Guards and Handrails."

Amendments to the stairs, guards and handrails provisions will come into force on January 1, 2022.

Part of the amendments to the code include new definitions for flight, run and tapered tread.  These new definitions are:

• Flight - a series of steps between landings
• Run - the horizontal distance between two adjacent tread nosings on a stair.
• Tapered Tread - a tread with non-parallel edges that increases or decreases its run uniformly over its width.

Key Changes

Spiral Stairs

In Section 9.8.3.1 is the introduction of (c) spiral stairs, added as a permission.  This is in addition to the previous (a) straight flights and (b) curved flights.  This addition comes with requirements, as outlined in 9.8.4.5A. Spiral Stairs:

a)      handrails on both sides, the outer handrail being not less than 1,070 mm high,

b)      a clear width not less than 660 mm between handrails,

c)      risers that are not more than 240 mm high,

d)     treads that,

 i.         are a minimum of 190 mm deep at a point 300 mm from the centre line of the inside handrail,

 ii.      have a consistent angle and uniform dimension, and

 iii.      turn in the same direction, and

e)      a clear height not less than 1,980 mm.

In addition,

2.  Spiral stairs conforming to Sentence (1) are permitted to be used as the only means of egress where they serve not more than 3 persons.

3.  Except as permitted by Sentence (2), spiral stairs shall not serve as an exit.

Runs

In the new code that will come into effect in January of 2022, the minimum run for rectangular treads has increased from 210 mm (8 1/4") to 255 mm (10").

This change has been a long time in the making, as the code change request was made in 1992, and was introduced in the NBCC in 2015.

Prior to implementing these changes, the National Research Council's Joint Task Group on Step Geometry did a substantial amount of research, and consulted many data sources, including:

• Most recent data available
• Canadian data and research
• International data and research
• Common practice

Canada already has some of the steepest stairs worldwide, with a max stair steepness of 44°, compared to the UK at 42°, the US and Australia at 38°.

When looking into fall injuries, the National Research Council's Assessment of Health Burdens found that:

• 21%  of all unintentional falls resulting in severe injuries are stair-related falls
• 82% of stair falls occur in residential settings.

In 2012, residential stair incidents included:

• 314 deaths
• 8,822 hospitalizations (including 820 brain injuries)
• 97,045 ER visits with no hospital admission
• $476 million in direct healthcare spending

It is noted that step geometry is the most critical factor relating to falls.  The research shows that shorter runs result in loss of balance, slipping off steps and missteps by tripping, overstepping, heel scuff, crabbing and foot overhang, while larger runs offer more space for better foot placement and larger foot sizes, and create greater margins of stability.  Canadian studies have shown that there is no direct correlation between fall incidence and rise (between 7" and 8"), but there is a direct correlation between fall incidence and run.  The new rise dimensions are estimated to reduce falls by 64%.

The new dimensions for runs will have an impact on the floor area.  The change will require an additional 6.3 square feet for 8-foot ceilings and 7.3 square feet for 9-foot ceilings.  It is estimated that over 118,000 starts, the economic impact will be $267 million for 8-foot ceilings and $290 million for 9-foot ceilings.

Tapered Treads

Section 9.8.4.3 - Dimensions for Tapered Treads has also been amended, and now reads as follows:

1.      tapered treads shall have a run that,

b.  complies with the dimensions for rectangular treads specified in Table 9.8.4.1. (i.e. 255 mm) when measured at a point 300 mm from the centre line of the inside handrail.

4.   Tapered treads in a flight shall have a uniform run in accordance with the tolerances described in Sentence (3) when measured at a point 300 mm from the centre line of the inside handrail.

a.      5 mm between adjacent treads, and

b.      10 mm between the deepest and shallowest treads in a flight.

Section 9.8.4.4A. Uniformity of Runs in Flights with Mixed Treads within a House or Dwelling Unit has been amended to as follows:

1.    where a flight consists of both tapered treads and rectangular treads, all the treads shall have a uniform run when measured at a point 300 mm from the centre line of the inside handrail.

2.      where tapered treads are located at the bottom of a mixed-tread flight of the run of the tapered treads when measured at a point 300 mm from the centre line of the inside handrail is permitted to exceed the run of the rectangular treads.

Section 9.8.3.1. Straight and Curved Runs in Stairs has been amended to read:

2. (b) flights with a mix of rectangular and tapered treads provided all tapered treads within a flight turn in the same direction.

Handrails

Section 9.8.7.1. Required Handrails has been amended to:

5.  Except for stairs with winders, where a flight of stairs within a house or an individual dwelling unit consists of tapered treads, or a mix of tapered treads and rectangular treads, one handrail shall be installed along the narrow end of the treads.

Section 9.8.7.4. Height of Handrails has been amended to:

Handrails shall be 865 mm to 1070 mm high (from 965 mm).

Section 9.8.7.5. Ergonomic Design has been amended to:

1.  The clearance between a handrail and any surface behind it shall be not less than,

(a) 60 mm, if the surface behind the handrail is rough or abrasive, or

(b) 50 mm, in all other cases.