Canadian Stair Building Code
includes stair dimensions, configurations, and step dimensions described in
BC Building Code 2012 and Ontario Building Code 2012.
22.214.171.124 Stair Construction
Stairs must be constructed in accordance with the following:
(a) Each flight must have not more than 18 nor less than 2 risers.
(b) The nominal dimension of goings and risers of a stair must be constant throughout each stair flight except that
the going of winders in lieu of a quarter or half landing may vary from the going of the straight treads within the
same flight provided that the going of all such winders is constant.
(c) Treads must be of solid construction (not mesh or other perforated material) if the stairway is more than 10m
high or connects more than 3 storeys.
(d) A flight of stairs must not have more than 3 winders in lieu of each quarter landing or 6 winders in lieu of each
(e) The riser opening must not allow a 125mm sphere to pass through between the treads.
(f) Treads must have a slip-resistant finish or a suitable non-skid strip near the edge of the nosings.
(g) Landings must-
(i) Be not less than 750mm long and where this involves a change in direction, the length is measured
500mm from the inside edge of the landing (see Figure 126.96.36.199, Diagram a); and
(ii) Have a gradient not steeper than 1:50; and
(iii) Be provided where the sill of a threshold of a doorway opens on to a stair that provides a change in floor
level or floor to ground level greater than 3 risers or 570mm (see Figure 188.8.131.52, Diagram b).
184.108.40.206 Riser and Going Dimensions
The riser and going dimensions for each flight, except for the going of winders in lieu of a quarter or half landing,
must comply with the following:
(a) The going (G), riser (R) and slope relationship quantity (2R+G) must be in accordance with Figure 220.127.116.11.
(b) The point for measurement of the going (G) in the slope relationship quantity as described in Figure 18.104.22.168
(i) For tapered treads (other than treads in a spiral stair)-
(A) Not more than 1m wide, the middle of the unobstructed width of the stair (see Figure 22.214.171.124,
Diagram b); and
(B) More than 1m in width, 400mm from the unobstructed width of each side of the stair (see Figure
126.96.36.199, Diagram c); and
(ii) For treads in spiral stairs, the point seven tenths of the unobstructed distance from the face of the centre
pole or support towards the handrail side (see Figure 188.8.131.52).
Measurement for openings in stairs
Private Staircase– for a domestic property.
Institutional & Assembly Stairs– are for serving a place where a substantial number of people will gather.(Public Staircase).
Other – are defined as offices, disabled, factories and common stairsserving morethan one dwelling. (Semi Public Staircase).
For the actual stair & staircase building regulation for this issue go to Point 1.2 (Page 6) atBuilding Regulations Part K.
The Rise And Going.
The most important regulation regarding domestic staircases is that:
1.Maximum rise of staircase 220mm.
2.Minimum going of staircase 220mm.
Private Staircase (Domestic) Max Rise = 220mm, min going 220mm.
Institutional & Assembly Max Rise = 180mm, min going 280mm.
Other (Semi Public) Max Rise =190mm, min going 250mm.
2. The maximum pitch of a domestic property is 42°
Private Staircase(Domestic) = 42° Maximum.
Institutional & Assembly Stairs (Public) = 33° Maximum.
Other (Semi Public) = 38° Maximum.
Please Note –that your stair tread cannot be too long or the riser too short because building regulation salsostate:
Twice the rise plus the going (2R+G) should be between 550mm and 700mm. For the actual stair & staircase building regulation regarding categoriesforsteepness of stairs go to 1.3; 1.4; 1.5; & 1.6 (Page 6) atBuilding Regulations Part K
Construction of Steps.
Building regulations stipulate that staircase steps should be level. Nosings should be at least 16mm.
For the actual stair & staircase building regulation regarding construction of steps go to point 1.8 (Page 6) atBuilding Regulations Part K.
All stairs which have open risers should be constructed so that a 100mm sphere cannot pass through.
This regulation has been stipulated by the government in order that children’s heads cannot get stuck in any opening. For the actual stair & staircase building regulation regarding Open risers go to point 1.9 (Page 6) atBuilding Regulations Part K.
A headroom of 2m is required at all points on and off a staircase and as you pass down a staircase.
For the actual stair and staircase building regulation regarding Headroom go to point 1.10 (Page 7)Building Regulations Part K.
Headroom for Loft Conversions.
For loft conversions the headroom will pass the building regulations if the centre of the stair width is 1.9m reducing to 1.8m at the side of the stair.
Please Note – Where there are real difficulties in the height some building control officers will allow you to build a newel out from the wall to meet the regulations. This does make the staircase narrower but this may be the only option.
For the actual stair and staircase building regulation regarding Headroom go to point 1.10 (Page 7) at Building Regulations Part K.
MINIMUM WIDTH OF STAIRCASE.
There are no recommendations as to the width of a staircase – Yes Really!
There are rules for direct fire escapes and disabled access and you will have to consult Part M of the building regulations Building Regulations Part Mand talk to your building control officer who can interpret these rules differently.
However Pear Stairs recommend: To make a staircase visually pleasing and comfortable we would recommend that you don’t try to have a staircase narrower than 860mm overall string.
For the actual stair and staircase building regulation regarding minimum width of staircase go to point 1.11 (Page 7) at Building Regulations Part K.
MAXIMUM WIDTH OF STAIRCASE.
The maximum width of a public staircase is 1800mm. However this is easily overcome by putting an additional handrail, newel and spindles in the staircase.
Building Code Requirement Highlights
- Minimum clear walking path of 26 inches. A 5-foot diameter or larger stair will provide this width
- Each tread will have a minimum of 7 1/2 inch tread depth at 12 inches from the narrow edge
- All treads will be identical
- The tread rise shall not be more than 9 1/2 inches high
- Minimum headroom of 6 foot 6 inches shall be provided, measuring plumb from the edge of the platform down to the tread below
- Landing width shall not be less than the required width of the stairway. Minimum spiral stair tread width is 26 inches – Salter’s code platforms start at 31 inches wide
- Stair balusters shall be spaced so a 4-inch object cannot pass between. The IRC Code permits a 4 3/8 inch space
- Balcony/Well Enclosure guardrail balusters shall be spaced so a 4-inch object cannot pass
- Balcony/Well Enclosure guardrail height shall not be less than 36 inches – If your state or municipality requires 42-inch tall guardrails, the sales order must reflect this detail
- The stairway shall be equipped with one handrail on the wide edge of the tread
- Handrail height, measured vertically from the tread nosing, shall be not less than 34 inches and not more than 38 inches
- Handrail grip size
- Type I-Handrails with a circular cross section shall have an outside diameter of at least 1 1/4 inches and not greater than 2 inches – Salter’s standard circular handrail is 1 1/2 inch diameter. This will address the UBC minimum cross section of 1 1/2 inch diameter. If the handrail is not circular, it shall have a perimeter dimension not greater than 6 1/4 inches
- Type II-Handrails, with a perimeter greater than 6 1/4 inches, shall provide a graspable finger recess area on both sides of the profile. For further information on our Type II options, please contact our sales department
- Verify what handrail size and shape your inspector will require. Handrail size and shape are a very controversial area within the building code. We recommend that you use our standard 1 1/2″ round handrails or our 1 3/4″ x 1 3/4″ solid wood handrail to comply with the proper circumference
- A 300 lb. concentrated load is required. On request, our sales department can provide structural calculations for your job specifications