Plumbing and Part 9 items used in large buildings (Complex Buildings)

Last updated October 22, 2026

Values this chapter turns on

max shower or tub water in hospitals and care homes: 43°C; max shower or tub water in hospitals and care homes
max shower or bathtub water temperature, general: 49°C; max shower or bathtub water temperature, general
guard height at exterior stairs over 10 m up: 1,500 mm; guard height at exterior stairs over 10 m up
maximum rise, public stairs under Part 9: 180 mm; maximum rise, public stairs under Part 9

The Complex Buildings syllabus borrows a set of Part 7 and Part 9 articles. Part 3 points to them for things like dwelling unit rooms, stairs inside suites, lighting outlets and cladding. Expect questions on hot water temperature limits in care buildings, on stair, guard and handrail numbers, and on a few room, glass and duct rules. This chapter skips 9.5.2., 9.5.4. and the door size articles 9.5.5.1. and 9.5.5.2., which the syllabus excludes.

Plumbing facilities and water temperature control

Plumbing facilities are provided under Subsection 3.7.4. and Section 9.31. (OBC Div. B 7.1.1B.1.). A floor drain goes in a public laundry, garbage room, incinerator room or boiler room outside a dwelling unit, and in a dwelling unit basement where gravity drainage is possible (7.1.1B.2.). Fixtures go only in rooms lit and ventilated to Parts 3, 6 and 9, and all equipment stays readily accessible (7.1.3.1., 7.1.3.2.).

Hot water limits (7.2.10.7., 7.2.10.7A., 7.2.10.7B.):

Situation	Limit
Shower head or bathtub, general	49°C maximum
Shower head or bathtub, healthcare facilities and retirement homes	43°C maximum, adjusted at the fixture controls
Bathtub, shower or hand basin a Group B, Division 2 or 3 patient or resident can reach	staff-only gauge and control, set to 43°C or less
Shower valve high-limit stop	set at 49°C maximum
Dishwashers and clothes washers	the 49°C limit does not apply

Showers and tubs are fed through an automatic compensating valve, with waivers for tub-only supplies and single tempered water lines. Fixed shower heads need pressure-balanced or thermostatic-mixing valves. Deck-mounted hand-held sprays are exempt from the thermal shock rules.

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Room design, glass and windows

Section 9.5. covers dwelling units used as a principal residence (9.5.1.0A.). Ceiling heights follow Table 9.5.3.1. (9.5.3.1.). Living rooms, dining rooms and kitchens need 2,300 mm over at least 75% of the required area. Passages and halls need 2,100 mm. A secondary suite may drop to 1,950 mm. Bedrooms are at least 7 m², or 6 m² with built-in cabinets (9.5.3D.1.).

Glass (9.6.1.4.). Safety glazing or wired glass is needed in these places:

sidelights over 500 mm wide that could be mistaken for doors;
storm doors and sliding doors at dwelling unit entrances and in public areas;
entrance door glass over 0.5 m² that comes within 900 mm of the bottom of the door.

Transparent panels that look like a way out get barriers, and public glass doors get hardware that makes them obvious. Shower and tub enclosures use Class A safety glazing.

Windows. Minimum glass areas follow Table 9.7.2.3. (9.7.2.3.). Living and dining rooms need 10% of the area served, and bedrooms 5%. Kitchens need 10% unless there is electric lighting. The glass in a door or skylight counts. Dwelling unit windows within 2 m of the ground meet the forced-entry clause of the window standard (9.7.5.3.). Swinging entrance doors to dwelling units, and swinging doors into a dwelling unit from an attached or storage garage, must resist forced entry (9.7.5.2.): wood doors are solid core or stile-and-rail and at least 45 mm thick, and the deadbolt has at least 5 pins and a 25 mm bolt throw. A door assembly meeting Grade 10 of ASTM F476 is exempt from these details.

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Stairs, ramps, handrails and guards

Section 9.8. separates private stairs (within or serving one dwelling unit or a house with a secondary suite) from public stairs (everything else except service stairs) (Table 9.8.4.1.).

Item	Private	Public
Rise	125 to 200 mm	125 to 180 mm
Run (rectangular treads)	255 to 355 mm	280 mm minimum, no maximum
Exit stair width	860 mm (single dwelling unit)	900 mm minimum (9.8.2.1.)
Headroom	1,950 mm	2,050 mm (9.8.2.2.)
Guard height	900 mm inside a dwelling unit	1,070 mm (9.8.8.3.)

Other key values:

Riser tolerance: 5 mm between adjacent risers and 10 mm across a flight. Tread slope is at most 1 in 50 (9.8.4.4.).
Ramp slope: 1 in 10 for exterior ramps and residential interiors, 1 in 6 for industrial, 1 in 8 for all others (9.8.5.4.).
Handrails: 865 mm to 1,070 mm high (9.8.7.4.). Where a stair must be 2,200 mm wide or more for its occupant load, no point may be over 825 mm from a handrail (9.8.7.1.).
Guards are required where the drop is more than 600 mm within 1.2 m of the walking surface (9.8.8.1.). Exterior stairs and landings more than 10 m above the ground need guards at least 1,500 mm high.
Guard openings stop a 100 mm sphere, and the triangle under a stair guard stops a 150 mm sphere (9.8.8.5.). Between 140 mm and 900 mm above the floor, nothing may make the guard climbable (9.8.8.6.).

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Cladding and interior finishes

Lumber siding is sound and free of knot holes and splits (9.27.6.1.). Drop, lapped and vertical wood siding is at least 14.3 mm thick and no more than 286 mm wide (9.27.6.2.). Overlap is 1 mm per 16 mm of width, but at least 25 mm for lapped bevel siding (9.27.6.3.). Vinyl siding meets ASTM D3679. Where vinyl needs a flame-spread rating, it is tested to CAN/ULC-S102.2 (9.27.12.1.).

Single-layer gypsum board on wood framing (9.29.5.):

Location	Nail spacing
Ceilings	180 mm o.c., or pairs at 300 mm
Walls	200 mm o.c., or pairs at 300 mm
Walls used for bracing or fire protection	200 mm o.c., including plates

Nails stay at least 10 mm from board edges. In cold weather, keep at least 10°C for 48 h before and after taping (9.29.5.10.).

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Duct materials and lighting outlets

Ducts are steel, aluminum, copper, clay or similar noncombustible material (9.33.6.2.). Combustible ducts need a Class 1 rating and cannot serve vertical runs over 2 storeys or air above 120°C. Duct sealants are limited to flame-spread 25 and smoke developed 50. Combustible duct connectors are at most 4 m long, horizontal only, and never through fire separations. Foamed plastic duct insulation is limited (9.33.6.4.): metal ducts only, at least 3 m from the furnace bonnet, and 50°C or less inside.

Lighting outlets (9.34.2.):

Every residential entrance gets an exterior light. A multi-suite entrance may use a staff-only switch.
Stairways with 4 or more risers in dwelling units get 3-way switches (9.34.2.3.).
Unfinished basements get one outlet per 30 m² (9.34.2.4.).
Public and service areas meet Table 9.34.2.7.. For example, public water closet rooms need 100 lx and service rooms 200 lx (9.34.2.7.).

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Common traps

Using 49°C in a hospital or retirement home. The limit there is 43°C.
Applying private stair dimensions to a corridor stair in an apartment building. That is a public stair: 180 mm maximum rise, 280 mm minimum run.
Giving a public exterior landing 15 m above grade a 1,070 mm guard. Above 10 m it is 1,500 mm.
Allowing a combustible duct in a vertical run serving 3 storeys.

Chapter review

Chapter at a glance

One line per section: the idea to carry into the exam. Then the answers that most often catch candidates out.

Chapter at a glance: the key idea in each section
Section	Key idea
Plumbing facilities and water temperature control	Plumbing facilities are provided under Subsection 3.7.4. and Section 9.31.. A floor drain goes in a public laundry, garbage room, incinerator room or boiler room outside a…
Room design, glass and windows	Section 9.5. covers dwelling units used as a principal residence.
Stairs, ramps, handrails and guards	Section 9.8. separates private stairs (within or serving one dwelling unit or a house with a secondary suite) from public stairs (everything else except service stairs).
Cladding and interior finishes	Lumber siding is sound and free of knot holes and splits.
Duct materials and lighting outlets	Ducts are steel, aluminum, copper, clay or similar noncombustible material.

Plumbing facilities and water temperature control
Plumbing facilities are provided under Subsection 3.7.4. and Section 9.31.. A floor drain goes in a public laundry, garbage room, incinerator room or boiler room outside a…
Room design, glass and windows
Section 9.5. covers dwelling units used as a principal residence.
Stairs, ramps, handrails and guards
Section 9.8. separates private stairs (within or serving one dwelling unit or a house with a secondary suite) from public stairs (everything else except service stairs).
Cladding and interior finishes
Lumber siding is sound and free of knot holes and splits.
Duct materials and lighting outlets
Ducts are steel, aluminum, copper, clay or similar noncombustible material.

Usual exam traps

Using 49°C in a hospital or retirement home. The limit there is 43°C.
Applying private stair dimensions to a corridor stair in an apartment building. That is a public stair: 180 mm maximum rise, 280 mm minimum run.
Giving a public exterior landing 15 m above grade a 1,070 mm guard. Above 10 m it is 1,500 mm.
Allowing a combustible duct in a vertical run serving 3 storeys.

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Code cited in this chapter

Based on the official 2024 Building Code Compendium on ontario.ca.

OBC Div. B 7.1.1B.1. Facilities Required
(1)Plumbing facilities shall be provided in accordance with Subsection 3.7.4. and Section 9.31.
Open OBC Div. B 7.1.1B.1. in the code viewer
OBC Div. B 7.1.1B.2. Floor Drains
(1)Where gravity drainage to a sanitary drainage system is possible, a floor drain shall be installed in a basement forming part of a dwelling unit.
(2)Where gravity drainage to a sanitary drainage system is not possible, the floor drain required by Sentence (1) may be connected to a storm drainage system, dry well or drainage ditch provided it is located where it can receive only clear-water waste or storm sewage.
(3)A floor drain shall be provided in a public laundry room, garbage room, incinerator room, boiler or heating room that is not located within a dwelling unit.
Open OBC Div. B 7.1.1B.2. in the code viewer
OBC Div. B 7.1.3.1. Lighting and Ventilation Requirements
(1)Plumbing fixtures shall not be installed in a room that is not lighted and ventilated in accordance with the appropriate requirements in Parts 3, 6 and 9.
Open OBC Div. B 7.1.3.1. in the code viewer
OBC Div. B 7.1.3.2. Accessibility
(1)Every fixture, plumbing appliance, interceptor, cleanout, valve, device or piece of equipment shall be located so that it is readily accessible for use, cleaning and maintenance.
Open OBC Div. B 7.1.3.2. in the code viewer
OBC Div. B 7.2.10.7. Water Temperature Control
(1)Except as provided in Sentences (2) and (3), water supplied to shower heads or bathtubs shall be controlled by an automatic compensating valve conforming to
(a)ASME A112.18.1 / CSA B125.1, "Plumbing Supply Fittings," or
(b)ASSE 1016 / ASME A112.1016 / CSA B125.16, "Performance Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations."
(2)The requirement in Sentence (1) is permitted to be waived where hot water supplied only to bathtubs is controlled by
(a)an automatic compensating valve conforming to CSA B125.3, "Plumbing fittings," or
(b)a temperature-limiting device conforming to ASSE 1070 / ASME A112.1070 / CSA B125.70, "Performance requirements for water temperature limiting devices."
(3)The requirement in Sentence (1) is permitted to be waived where the water is supplied by a single tempered water line controlled by an automatic compensating valve conforming to CSA B125.3, "Plumbing fittings."
(4)Except as provided in Sentences (5) and (6) and 7.2.10.7A.(1), the temperature of water discharging from a shower head or into a bathtub shall not exceed 49°C.
(5)In healthcare facilities and retirement homes, the temperature of water discharging from a shower head or into a bathtub shall
(a)not exceed 43°C, and
(b)be adjusted at the shower or bathtub controls.
(6)Sentence (4) does not apply to hot water supplied to installed dishwashers or clothes washers.
Open OBC Div. B 7.2.10.7. in the code viewer
OBC Div. B 7.2.10.7A. Temperature Control Devices
(1)A water distribution system supplying hot water to any bathtub, shower or hand basin that is accessible to a patient or resident in a Group B, Division 2 or 3 occupancy or a resident of a group home, home for special care or residence for adults with developmental disabilities, or children within child care facilities shall have one or more temperature gauges and control devices that are
(a)accessible only to supervisory staff, and
(b)capable of being adjusted to ensure that the temperature of the water supplied to the fixtures does not exceed 43°C.
Open OBC Div. B 7.2.10.7A. in the code viewer
OBC Div. B 7.2.10.7B. Showers
(1)Except as provided for in Sentences (2) and (3), all valves supplying fixed location shower heads, shall be individually pressure-balanced or thermostatic-mixing valves, conforming to ASME A112.18.1 / CSA B125.1, "Plumbing Supply Fittings."
(2)An individually pressure-balanced or thermostatic-mixing valve is not required for shower heads having a single tempered water supply that is controlled by an automatic compensating valve conforming to CSA B125.3, "Plumbing fittings."
(3)Deck-mounted, hand-held, flexible-hose spray attachments are exempt from the thermal shock requirements of Sentences (1) and (4).
(4)Pressure-balanced, thermostatic-mixing or combination pressure-balanced and thermostatic-mixing type valves shall
(a)capable of limiting thermal shock, and
(b)designed so that the outlet temperature does not exceed 49°C or equipped with high-limit stops which shall be adjusted to a maximum hot water setting of 49°C.
Open OBC Div. B 7.2.10.7B. in the code viewer
OBC Div. B 9.5.1.0A. Application
(1)Except as otherwise specified in this Part, this Section applies only to dwelling units that are intended for use on a continuing or year-round basis as the principal residence of the occupant.
Open OBC Div. B 9.5.1.0A. in the code viewer

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OBC Div. B Table 9.5.3.1. Room Ceiling Heights — Forming Part of Sentences 9.5.3.1.(1) and (4)
Table 9.5.3.1 — Room Ceiling Heights — Forming Part of Sentences 9.5.3.1.(1) and (4) Room or Space | Minimum Heights[1] Living room or space, dining room or space, kitchen or kitchen space | 2,300 mm over at least 75% of the required floor area with a clear height of 2,100 mm at any point over the required area Bedroom or bedroom space | 2,300 mm over at least 50% of the required area or 2,100 mm over all of the required floor area. Any part of the floor having a clear height of less than 1,400 mm shall not be considered in computing the required floor area Basement space | 2,100 mm over at least 75% of the basement area except that under beams and ducts the clearance is permitted to be reduced to 1,950 mm Bathroom, water closet room or laundry area above grade | 2,100 mm in any area where a person would normally be in a standing position Passage, hall or main entrance vestibule and finished rooms not specifically mentioned above | 2,100 mm Notes to Table 9.5.3.1.: (1) Area of the space shall be measured at floor level.
Open OBC Div. B Table 9.5.3.1. in the code viewer
OBC Div. B 9.5.3.1. Ceiling Heights of Rooms or Spaces
(1)Except as provided in Sentences (2) and (3), the ceiling heights and clear heights in rooms or spaces in residential occupancies and live/work units shall conform to Table 9.5.3.1.
(2)Ceiling heights in secondary suites shall be not less than 1.95 m.
(3)Clear heights under beams and ducting in secondary suites shall be not less than 1.85 m.
(4)Areas in rooms or spaces over which ceiling height and clear height are not less than the minimum specified in Table 9.5.3.1. or Sentence (2) or (3) shall be contiguous with the entry or entries to those rooms or spaces.
Open OBC Div. B 9.5.3.1. in the code viewer
OBC Div. B 9.5.3D.1. Areas of Bedrooms
(1)Except as provided in Articles 9.5.3D.2. and 9.5.3D.3., bedrooms in dwelling units shall have an area not less than 7m² where built-in cabinets are not provided and not less than 6m^2 where built-in cabinets are provided.
Open OBC Div. B 9.5.3D.1. in the code viewer
OBC Div. B 9.6.1.4. Types of Glass and Protection of Glass
(1)Glass sidelights greater than 500 mm wide that could be mistaken for doors, glass in storm doors and glass in sliding doors within or at every entrance to a dwelling unit and in public areas shall be
(a)safety glazing of the tempered or laminated type conforming to CAN/CGSB-12.1, "Safety Glazing," or
(b)wired glass conforming to CAN/CGSB-12.11-M, "Wired Safety Glass."
(2)Except as provided in Sentence (4), glass in entrance doors to dwelling units and in public areas, other than the entrance doors described in Sentence (1), shall be safety glazing or wired glass of the type described in Sentence (1) where the glass area exceeds 0.5m^2 and extends to less than 900 mm from the bottom of the door.
(3)Except as provided in Sentence (4), transparent panels that could be mistaken as a means of egress shall be protected by barriers or railings.
(4)Sliding glass partitions that separate a public corridor from an adjacent occupancy and that are open during normal working hours need not conform to Sentences (2), (3) and (5), except that such partitions shall be suitably marked to indicate their existence and position.
(5)Except as provided in Sentence (4), every glass or transparent door accessible to the public shall be equipped with hardware, bars or other permanent fixtures designed so that the existence and position of such doors is readily apparent.
(6)Glazing used for a shower or bathtub enclosure shall conform to Class A of CAN/CGSB-12.1, "Safety Glazing."
Open OBC Div. B 9.6.1.4. in the code viewer
OBC Div. B Table 9.7.2.3. Glass Areas for Rooms of Residential Occupancy — Forming Part of Sentence 9.7.2.3.(1)
Table 9.7.2.3 — Glass Areas for Rooms of Residential Occupancy — Forming Part of Sentence 9.7.2.3.(1) Location | Minimum Unobstructed Glass Area — With No Electric Lighting | Minimum Unobstructed Glass Area — With Electric Lighting Laundry, basement recreation room, unfinished basement | 4% of area served | Windows not required Water-closet room | 0.37 m² | Windows not required Kitchen space | 10% of area served | Windows not required Kitchen alcove | 10% of area served | Windows not required Living rooms and dining rooms | 10% of area served | 10% of area served Bedrooms and other finished rooms not mentioned above | 5% of area served[1] | 5% of area served[1] Notes to Table 9.7.2.3.: (1) See Subsection 9.9.10.
Open OBC Div. B Table 9.7.2.3. in the code viewer
OBC Div. B 9.7.2.3. Minimum Window Areas
(1)Except as required in Article 9.9.10.1. and Sentence (3), the minimum window glass areas for rooms in buildings of residential occupancy or rooms that are used for sleeping shall conform to Table 9.7.2.3.
(2)The unobstructed glass area of a door or skylight is considered equivalent to that of a window.
(3)Work areas in live/work units shall conform to Clause 3.7.2.1.(2)(a).
(4)Where rooms with different requirements for window glass area are combined as described in Sentence 9.5.1.2.(1), the more restrictive requirement shall govern.
Open OBC Div. B 9.7.2.3. in the code viewer
OBC Div. B 9.7.5.3. Resistance to Forced Entry for Windows
(1)In dwelling units, windows, any part of which is located within 2 m of adjacent ground level, shall conform to the requirements for resistance to forced entry as described in Clause 5.3.6 of AAMA/WDMA/CSA 101/I.S.2/A440, "North American Fenestration Standard/Specification for windows, doors, and skylights." (See Note A-9.7.5.3.(1))
Open OBC Div. B 9.7.5.3. in the code viewer
OBC Div. B 9.7.5.2. Resistance to Forced Entry for Doors
(1)Except for exterior doors to garages and to other ancillary spaces, this Article applies to
(a)swinging entrance doors to dwelling units,
(b)swinging doors between dwelling units and attached garages or other ancillary spaces, and
(c)swinging doors that provide access directly or indirectly from a storage garage to a dwelling unit. (See Note A-9.7.5.2.(1))
(2)Doors, frames and hardware that conform to a security level of at least Grade 10 as described in the Annex to ASTM F476, "Standard Test Methods for Security of Swinging Door Assemblies," are not required to conform to Sentences (3) to (7). (See Note A-9.7.5.2.(2))
(3)Except as permitted in Sentence (2), wood doors as described in Sentence (1) shall
(a)be solid core or stile-and-rail type,
(b)be not less than 45 mm thick, and
(c)if of the stile-and-rail type, have a panel thickness of not less than 19 mm, with a total panel area not more than half of the door area.
(4)Except as permitted in Sentence (2), doors described in Sentence (1) shall be provided with
(a)a deadbolt lock with a cylinder having no fewer than 5 pins, and
(b)a bolt throw not less than 25 mm long, protected with a solid or hardened free-turning ring or beveled cylinder housing. (See Article 9.9.6.7.)
(5)Except as permitted in Sentence (2), an inactive leaf in double doors used in locations specified in Sentence (1) shall be provided with heavy-duty bolts top and bottom having an engagement of not less than 15 mm.
(6)Except as permitted in Sentence (2), hinges for doors described in Sentence (1) shall be fastened
(a)to wood doors with wood screws not less than 25 mm long and to wood frames with wood screws such that at least 2 screws per hinge penetrate not less than 30 mm into solid wood, or
(b)to metal doors and metal frames with machine screws not smaller than No. 10 and not less than 10 mm long. (See Note A-9.7.5.2.(6))
(7)Strikeplates for deadbolts described in Sentence (4) shall be fastened
(a)to wood frames with wood screws that penetrate not less than 30 mm into solid wood, or
(b)to metal frames with machine screws not smaller than No. 8 and not less than 10 mm long. (See Note A-9.7.5.2.(6))
(8)Except for storm doors or screen doors, doors described in Sentence (1) that swing outward shall be provided with hinges or pins so that the doors cannot be removed when they are in the closed position. (See Note A-9.7.5.2.(8))
(9)Solid blocking shall be provided on both sides at the lock height between the jambs for doors described in Sentence (1) and the structural framing so that the jambs will resist spreading by force.
Open OBC Div. B 9.7.5.2. in the code viewer
OBC Div. B Table 9.8.4.1. Rise for Rectangular Treads, Tapered Treads and Winders and Run for Rectangular Treads — Forming Part of Sentences 9.8.4.1.(1) and 9.8.4.2.(1)
Table 9.8.4.1 — Rise for Rectangular Treads, Tapered Treads and Winders and Run for Rectangular Treads — Forming Part of Sentences 9.8.4.1.(1) and 9.8.4.2.(1) Stair Type | Max. Rise, mm, for All Steps | Min. Rise, mm, for All Steps | Max. Run, mm, for Rectangular Treads | Min. Run, mm, for Rectangular Treads Private stairs[1] | 200 | 125 | 355 | 255 Public stairs[2] | 180 | 125 | no limit | 280 Service stairs[3] | no limit | 125 | 355 | no limit Stairs to unoccupied attic space[4] | no limit | 125 | 355 | no limit Stairs to crawl spaces | no limit | 125 | 355 | no limit Stairs that serve mezzanines not exceeding 20 m² within live/work units | no limit | 125 | 355 | no limit Notes to Table 9.8.4.1.: (1) Private stairs are: (a) interior stairs within a house with a secondary suite or an individual dwelling unit, (b) exterior stairs serving a house with a secondary suite or an individual dwelling unit, and (c) exterior stairs serving a garage that serves a house with a secondary suite or an individual dwelling unit. (2) Public stairs are all stairs not described as service stairs or private stairs. (3) Service stairs are stairs that serve areas used only as service rooms or service spaces. (4) Stairs to unoccupied attic space are stairs that serve attics containing no storage or living space.
Open OBC Div. B Table 9.8.4.1. in the code viewer
OBC Div. B 9.8.2.1. Stair Width
(1)Except as provided in Sentence (2) and Article 9.8.4.7., required exit stairs and public stairs serving buildings of residential occupancy shall have a width of not less than 900 mm.
(2)Exit stairs serving a single dwelling unit or a house with a secondary suite including their common spaces shall have a width of not less than 860 mm.
(3)Except as provided in Article 9.8.4.7., required exit stairs and public stairs serving buildings of other than residential occupancy shall have a width of not less than the greater of
(a)900 mm, or
(b)8 mm per person based on the occupant load limits specified in Table 3.1.17.1.
(4)Except as provided in Article 9.8.4.7., at least one stair between each floor level within a dwelling unit, and exterior stairs serving a single dwelling unit except required exit stairs, shall have a width of not less than 860 mm.
Open OBC Div. B 9.8.2.1. in the code viewer
OBC Div. B 9.8.2.2. Height Over Stairs
(1)The clear height over stairs shall be measured vertically, over the clear width of the stair, from a straight line tangent to the tread and landing nosings to the lowest point above. (See Note A-3.4.3.4.)
(2)Except as provided in Sentences (3) and (4) and Article 9.8.4.7., the clear height over stairs shall not be less than 2,050 mm.
(3)Except as provided in Article 9.8.4.7., the clear height over stairs serving a single dwelling unit or a house with a secondary suite including their common spaces shall not be less than 1,950 mm.
(4)The clear height over stairs that are located under beams and ducting in secondary suites shall not be less than 1,850 mm.
Open OBC Div. B 9.8.2.2. in the code viewer
OBC Div. B 9.8.8.3. Height of Guards
(1)Except as provided in Sentences (2) to (3.1), all guards shall be not less than 1,070 mm high.
(2)All guards within dwelling units or within houses with a secondary suite including their common spaces shall be not less than 900 mm high.
(3)Exterior guards serving not more than one dwelling unit or a house with a secondary suite including their common spaces shall be not less than 900 mm high where the walking surface served by the guard is not more than 1,800 mm above the finished ground level.
(3.1)The height of guards for exterior stairs and landings more than 10 m above adjacent ground level shall be not less than 1,500 mm.
(4)The height of guards for flights of steps shall be measured vertically from the top of the guard to a line drawn through the tread nosing served by the guard.
Open OBC Div. B 9.8.8.3. in the code viewer
OBC Div. B 9.8.4.4. Uniformity and Tolerances for Risers, Runs and Treads
(1)Except as provided in Sentence (2), risers shall be of uniform height in any one flight with a maximum tolerance of
(a)5 mm between adjacent treads or landings, and
(b)10 mm between the tallest and shortest risers in a flight.
(2)Except for required exit stairs, where the top or bottom riser in a stair adjoins a sloping finished walking surface such as a garage floor, driveway or sidewalk, the height of the riser across the stair shall vary by not more than 1 in 12.
(3)Rectangular treads shall have a uniform run with a maximum tolerance of
(a)5 mm between adjacent treads, and
(b)10 mm between the deepest and shallowest treads in a flight.
(4)Tapered treads in a flight shall have a uniform run in accordance with the construction tolerances stipulated in Sentence (3) when measured at a point 300 mm from the centre line of the handrail as described in Sentence 9.8.7.1.(5).
(5)The slope of treads shall not exceed 1 in 50.
Open OBC Div. B 9.8.4.4. in the code viewer
OBC Div. B 9.8.5.4. Ramp Slope
(1)The slope of ramps shall be not more than
(a)1 in 10 for exterior ramps,
(b)1 in 10 for interior ramps serving residential occupancies,
(c)1 in 6 for industrial occupancies, and
(d)1 in 8 for all other occupancies.
Open OBC Div. B 9.8.5.4. in the code viewer
OBC Div. B 9.8.7.4. Height of Handrails
(1)The height of handrails on stairs and ramps shall be measured vertically from the top of the handrail to
(a)a straight line drawn tangent to the tread nosings of the stair served by the handrail, or
(b)the surface of the ramp, floor or landing served by the handrail.
(2)Except as provided in Sentence (3), Clause 3.8.3.4.(1)(e) and Sentence 9.8.4.7.(1), required handrails shall be 865 mm to 1,070 mm high.
(3)Handrails installed in addition to required handrails need not comply with Sentence (2).
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OBC Div. B 9.8.7.1. Required Handrails
(1)Except as provided in Sentences (2) to (4), handrails shall be installed on stairs and ramps in conformance with Table 9.8.7.1.
(2)Where a stair or ramp is required to be at least 2,200 mm wide due to the occupant load, a handrail shall be installed such that no position on the stair or ramp is more than 825 mm from a handrail. (See Note A-9.8.7.1.(2))
(3)Handrails are not required for stairs and ramps serving a single dwelling unit, where
(a)interior stairs have not more than 2 risers,
(b)exterior stairs have not more than 3 risers, or
(c)ramps rise not more than 400 mm.
(4)Only one handrail is required on exterior stairs having more than 3 risers provided such stairs serve not more than one dwelling unit or a house with a secondary suite.
(5)Except for stairs with winders, where a flight of stairs within a 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.
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OBC Div. B 9.8.8.1. Required Guards
(1)Except as provided in Sentence (2) and except at the leading edge at the top of a flight, every surface to which access is provided, including but not limited to flights of steps and ramps, exterior landings, porches, balconies, mezzanines, galleries and raised walkways, shall be protected by a guard on each side that is not protected by a wall for the length where the difference in elevation is more than 600 mm between the walking surface and the adjacent surface within 1.2 m.
(2)Guards are not required
(a)at loading docks,
(b)at floor pits in repair garages, or
(c)where access is provided for maintenance purposes only.
(3)Doors in buildings of residential occupancy, where the finished floor on one side of the door is more than 600 mm above the floor or other constructed surface or ground level on the other side of the door, shall be protected by
(a)a guard, or
(b)a mechanism capable of controlling the free swinging or sliding of the door so as to limit any clear unobstructed opening to not more than 100 mm.
(4)Except as provided in Sentence (5), openable windows in buildings of residential occupancy shall be protected by
(a)a guard, or
(b)a mechanism that can only be released with the use of tools or special knowledge to control the free swinging or sliding operation of the openable part of the window so as to limit any clear unobstructed opening to not more than 100 mm measured either vertically or horizontally. (See Note A-9.8.8.1.(4))
(5)Windows need not be protected in accordance with Sentence (4), where the bottom edge of the openable portion of the window is located
(a)more than 900 mm above the finished floor, or
(b)less than 1,800 mm above the floor or ground on the other side of the window. (See Note A-9.8.8.1.(4))
(6)Except as provided in Sentence (7), glazing installed over stairs, ramps and landings that extends to less than 1,070 mm above the surface of the treads, ramp or landing shall be
(a)protected by guards in accordance with this Subsection, or
(b)non-openable and designed to withstand the specified lateral loads for guards as provided in Article 4.1.5.14.
(7)In dwelling units, glazing installed over stairs, ramps and landings that extends to less than 900 mm above the surface of the treads, ramp or landing shall be
(a)protected by guards in accordance with this Subsection, or
(b)non-openable and designed to withstand the specified lateral loads for guards as provided in Article 4.1.5.14.
(8)Glazing installed in public areas that extends to less than 1 m from the floor and is located above the second storey in buildings of residential occupancy shall be
(a)protected by guards in accordance with this Subsection, or
(b)non-openable and designed to withstand the specified lateral loads for guards as provided in Article 4.1.5.14.
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OBC Div. B 9.8.8.5. Openings in Guards
(1)Except as permitted in Sentences (3) and (4), openings through guards shall be of a size that prevents the passage of a spherical object having a diameter of 100 mm. (See Note A-9.8.8.5.(1) and (3))
(2)Except for guards that serve industrial occupancies, the triangular openings formed by stair risers, stair treads and the bottom element of a required guard shall be of a size that prevents the passage of a 150 mm diam sphere.
(3)Except where they serve storage garages, guards in industrial occupancies are permitted to consist of
(a)a top railing, and
(b)one or more horizontal intermediate rails spaced such that the size of the openings through the guard prevents the passage of a spherical object having a diameter of 535 mm. (See Note A-9.8.8.5.(1) and (3))
(4)Openings through any guard that is not required by Article 9.8.8.1. and that serves an occupancy other than industrial occupancy, shall be of a size that
(a)prevents the passage of a spherical object having a diameter of 100 mm, or
(b)permits the passage of a spherical object having a diameter of 200 mm. (See Note A-9.8.8.5.(4))
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OBC Div. B 9.8.8.6. Guards Designed Not to Facilitate Climbing
(1)Guards required by Article 9.8.8.1., except those in industrial occupancies and where it can be shown that the location and size of openings do not represent a hazard, shall be designed so that no member, attachment or opening located between 140 mm and 900 mm above the floor or walking surface protected by the guard will facilitate climbing. (See Note A-9.8.8.6.(1))
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OBC Div. B 9.27.6.1. Materials
(1)Lumber siding shall be sound, free of knot holes, loose knots, through checks or splits.
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OBC Div. B 9.27.6.2. Thickness and Width
(1)Drop, rustic, novelty, lapped board and vertical wood siding shall be not less than 14.3 mm thick and not more than 286 mm wide.
(2)Bevel siding shall be
(a)not less than 5 mm thick at the top, and
(b)not less than
(i)12 mm thick at the butt for siding 184 mm or less in width, and
(ii)14.3 mm thick at the butt for siding wider than 184 mm.
(3)Bevel siding shall be not more than 286 mm wide.
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OBC Div. B 9.27.6.3. Joints
(1)Lumber siding shall prevent water from entering at the joints by the use of lapped or matched joints or by vertical wood battens.
(2)Siding shall overlap not less than 1 mm per 16 mm width of lumber, but not less than
(a)9.5 mm for matched siding,
(b)25 mm for lapped bevel siding, or
(c)12 mm for vertical battens.
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OBC Div. B 9.27.12.1. Material Standards
(1)Vinyl siding shall conform to ASTM D3679, "Standard Specification for Rigid Poly (Vinyl Chloride) (PVC) Siding."
(2)Insulated vinyl siding shall conform to ASTM D7793, "Standard Specification for Insulated Vinyl Siding."
(3)Rigid vinyl soffits shall conform to ASTM D4477, "Standard Specification for Rigid (Unplasticized) Poly(Vinyl Chloride) (PVC) Soffit."
(4)Where vinyl siding, insulated vinyl siding or rigid vinyl soffits are required to have a flame-spread rating, the rating shall be determined in accordance with CAN/ULC-S102.2, "Standard Method of Test for Surface Burning Characteristics of Flooring, Floor Coverings, and Miscellaneous Materials and Assemblies."
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OBC Div. B 9.29.5.8. Spacing of Nails
(1)For single-layer application on a ceiling, nails shall be spaced
(a)not more than 180 mm o.c. on ceiling supports, or
(b)every 300 mm o.c. along ceiling supports, in pairs about 50 mm apart.
(2)Where the ceiling sheets are supported by the wall sheets around the perimeter of the ceiling, this support may be considered as equivalent to nailing at this location.
(3)Except as required by Sentence (4), for single-layer application on walls, nails shall be spaced
(a)not more than 200 mm o.c. on vertical wall supports, or
(b)every 300 mm o.c. along vertical wall supports, in pairs about 50 mm apart.
(4)For single-layer application on walls, where gypsum board provides required bracing in braced wall panels, lateral support for studs, or fire protection, nails shall be spaced not more than 200 mm o.c. on
(a)vertical wall supports, and
(b)top and bottom plates. (See Article 9.23.10.2. and Section 9.10.)
(5)The uppermost nails on vertical wall supports shall be not more than 200 mm below the ceiling.
(6)Nails shall be located not less than 10 mm from the side or edge of the board.
(7)Nails shall be driven so that the heads do not puncture the paper.
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OBC Div. B 9.29.5.10. Low Temperature Conditions
(1)In cold weather, heat shall be provided to maintain a temperature not below 10° C for 48 h prior to taping and finishing and maintained for not less than 48 h thereafter.
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OBC Div. B 9.33.6.2. Materials in Air Duct Systems
(1)Except as provided in Sentences (2) to (6.2) and in Article 3.6.4.3., all ducts, duct connectors, associated fittings and plenums used in air duct systems shall be constructed of steel, aluminum alloy, copper, clay or similar noncombustible material.
(2)Ducts, associated fittings and plenums are permitted to contain combustible material provided they
(a)conform to the appropriate requirements for Class 1 duct materials in CAN/ULC-S110, "Standard Methods of Test for Air Ducts,"
(b)conform to Article 3.1.5.18. and Subsection 3.1.9.,
(c)are not used in vertical runs serving more than 2 storeys, and
(d)are not used in air duct systems in which the air temperature may exceed 120°C.
(3)Duct sealants shall have a flame-spread rating of not more than 25 and a smoke developed classification of not more than 50.
(4)Duct connectors that contain combustible materials and that are used between ducts and air outlet units shall
(a)conform to the appropriate requirements for Class 1 air duct materials in CAN/ULC-S110, "Standard Methods of Test for Air Ducts,"
(b)be limited to 4 m in length,
(c)be used only in horizontal runs, and
(d)not penetrate required fire separations.
(5)Combustibleducts that are part of a duct system carrying only ventilation air and that are contained entirely within a dwelling unit need not comply with the requirements of Sentences (1) to (4).
(6)Except as provided in Sentences 9.33.6.13.(2) and (3), ducts that are part of a return-air duct system and that are contained entirely within a dwelling unit need not comply with the requirements of Sentences (1) to (4).
(6.1)All ductwork and fittings shall be constructed and installed in conformance with SMACNA Manuals and ASHRAE Handbooks.
(6.2)All duct materials and fittings shall be
(a)suitable for exposure to the temperature and humidity of the air being conveyed, and
(b)resistant to corrosion due to contaminants in the air being conveyed in the duct.
(7)Materials referred to in Sentences (1) to (6.2), when used in a location where they may be subjected to excessive moisture, shall
(a)have no appreciable loss of strength when wet, and
(b)be corrosion-resistant.
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OBC Div. B 9.33.6.4. Coverings, Linings and Insulation
(1)Reserved.
(2)Reserved.
(3)Reserved.
(4)Reserved.
(5)Except as permitted in Sentences (6) and (7), foamed plastic insulation shall not be used as part of an air duct or for insulating an air duct.
(6)Foamed plastic insulation conforming to Article 9.25.2.2. is permitted to be used to insulate a galvanized steel, stainless steel or aluminum air duct, provided
(a)the foamed plastic insulation applied to supply ductwork is not less than 3 m from the furnace bonnet,
(b)the temperature within the ductwork where the insulation is installed is not greater than 50°C,
(c)duct joints are taped with a product conforming to Sentence 9.33.6.3.(1),
(d)return air plenums are separated from the foamed plastic insulation, and
(e)the foamed plastic insulation is protected in accordance with Article 9.10.17.10.
(7)Foamed plastic insulation is permitted to be used in a ceiling space that acts as a return air plenum provided the foamed plastic insulation is protected from exposure to the plenum in accordance with Sentence 3.1.5.14.(4).
(8)Reserved.
(9)Linings of ducts shall be installed so that they will not interfere with the operation of volume or balancing dampers or of fire dampers, fire stop flaps and other closures.
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OBC Div. B 9.34.2.1. Lighting of Entrances
(1)An exterior lighting outlet with fixture controlled by a wall switch located within the building shall be provided at every entrance to buildings of residential occupancy.
(2)The exterior lighting outlet with fixture required by Sentence (1) may be controlled by a wall switch or panel accessible to authorized personnel only, where it serves,
(a)a building entrance serving multiple suites of residential occupancy,
(b)multiple dwelling unit entrances,
(c)hotels, or
(d)motels.
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OBC Div. B 9.34.2.3. Stairways
(1)Every stairway shall be lighted.
(2)Except as provided in Sentence (3), 3-way wall switches located at the head and foot of every stairway shall be provided to control at least one lighting outlet with fixture for stairways with 4 or more risers in dwelling units and houses with a secondary suite including their common spaces.
(3)The stairway lighting for basements that do not contain finished space or lead to an outside entrance or built-in garage and which serve not more than one dwelling unit is permitted to be controlled by a single switch located at the head of the stairs.
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OBC Div. B 9.34.2.4. Basements
(1)A lighting outlet with fixture shall be provided for each 30 m² or fraction thereof of floor area in unfinished basements.
(2)The outlet required in Sentence (1) nearest the stairs shall be controlled by a wall switch located at the head of the stairs.
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OBC Div. B Table 9.34.2.7. Lighting for Public Areas - Forming Part of Sentences 9.34.2.7.(2) and (3)
Table 9.34.2.7. Lighting for Public Areas - Forming Part of Sentences 9.34.2.7.(2) and (3) Forming Part of Sentences 9.34.2.7.(2) and (3) Room or Space | Minimum Illumination, lx | Minimum Lighting Power Density, W/m² of floor area Storage rooms | 50 | 5 Service rooms and laundry areas | 200 | 20 Garages | 50 | 5 Public water closet rooms | 100 | 10 Service hallways and stairways | 50 | 5 Recreation rooms | 100 | 10 Hallways, corridors, stairways and sleeping areas in recreational camps and camps for housing of workers | 100 | 10 Kitchen in recreational camps and camps for housing of workers | 500 | 50 All other rooms in recreational camps and camps for housing of workers | 250 | 25
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OBC Div. B 9.34.2.7. Public and Service Areas
(1)Every public or service area in buildings, including a recreational camp and a camp for housing of workers, shall have lighting outlets with fixtures controlled by a wall switch or panel to illuminate such areas.
(2)When provided by incandescent lighting, illumination required in Sentence (1) shall conform to Table 9.34.2.7. (See Article 9.9.12.2. for lighting in means of egress.)
(3)When other types of lighting are used, illumination equivalent to that shown in Table 9.34.2.7. shall be provided.
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