Floor areas, exits, vertical transportation and service facilities (Small Buildings)

Last updated October 22, 2026

Values this chapter turns on

max travel distance, sprinklered (not F1): 45 m; max travel distance, sprinklered (not F1)
occupants: room needs 2 egress doorways: over 60; occupants: room needs 2 egress doorways
max capacity credited to a revolving door: 45 persons; max capacity credited to a revolving door
max dead-end public corridor, residential: 6 m; max dead-end public corridor, residential

The Small Buildings syllabus does not ask for all of Part 3 Sections 3.3 to 3.6. It picks a list of articles, and in several cases only one or two Sentences. Part 9 points to many of them (for example 9.10.1.3. sends hazardous areas and similar items to Part 3). This chapter walks through that list in the order the code prints it. Where the syllabus names a single Sentence, such as 3.3.1.9.(6) or 3.4.2.5.(1), focus on that Sentence.

Corridors, egress doorways and floor area safety

Public corridor separations. Normally a public corridor is separated from the rest of the storey by a fire separation. In a sprinklered floor area, Sentence (4) drops that separation in three cases: from the rest of the storey if travel distance to an exit is not more than 45 m; from a room or suite if the corridor is a wide, high, sprinklered "mall-type" corridor meeting 3.3.1.9.(4) and 3.4.2.5.(1)(d); and from a washroom space required by 3.7.4. if the washroom and corridor together are separated from the rest of the storey (OBC Div. B 3.3.1.4.).

Two egress doorways. Outside dwelling units, a room or suite needs at least 2 egress doorways when it is a high-hazard industrial space or hazardous room over 15 m², holds more than 60 occupants, or exceeds the area or travel limits for its group. The limits differ for unsprinklered and sprinklered floor areas (OBC Div. B 3.3.1.5.). In a sprinklered floor area (no high-hazard industrial) travel to an egress doorway over 25 m also triggers a second door. Two required doorways must be at least one third of the room's maximum diagonal apart.

Key values to practise reading (our selection, see the tables for the rest):

Group	Unsprinklered max area / distance	Sprinklered max area
A	150 m² / 15 m	200 m²
D	200 m² / 25 m	300 m²
E	150 m² / 15 m	200 m²

Source: OBC Div. B Table 3.3.1.5.-A and Table 3.3.1.5.-B.

Dead-end corridors. The syllabus lists 3.3.1.9.(6): a dead-end corridor is allowed in an assembly occupancy if every room or suite also has a second, separate egress doorway that does not lead into the dead end. For comparison, Sentence (7) allows a dead-end public corridor up to 6 m in a residential occupancy, and business, mercantile and low- or medium-hazard industrial occupancies get 9 m for up to 30 persons with self-closing doors (OBC Div. B 3.3.1.9.).

Janitors' rooms. A janitorial supply room needs a 1 h fire separation, reduced to 45 min where the floor assembly is allowed under 1 h, and no rating at all if the floor area is sprinklered throughout (OBC Div. B 3.3.1.22.).

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Assembly separations, doors and storage rooms

The seating area of a Group A, Division 1 occupancy (theatres and similar) is separated from the rest of the floor area by a 1 h fire separation once seating occupant load exceeds 200. It may drop to 45 min if the floor assembly rating is permitted below 1 h (OBC Div. B 3.3.2.2.). The syllabus lists only Sentences (1) and (2).

A latching door in the access to exit from an assembly room or suite holding more than 100 people needs the panic-type device described in 3.4.6.16.(3) (OBC Div. B 3.3.2.7.). A room storing flammable or combustible liquids under the Fire Code must not be above or below the first storey (OBC Div. B 3.3.2.16.).

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Hazardous areas, exhaust and welding

Where dust, fumes or vapours could cause fire or explosion, an exhaust system designed to Part 6 is required, and explosion venting is required where the principal use creates an explosion hazard (OBC Div. B 3.3.1.21.). Welding and cutting go in a room with a 1 h fire separation or an automatic extinguishing system, unless in an industrial occupancy where the work is no hazard to adjacent areas (OBC Div. B 3.3.1.26.).

Subsection 3.3.6. adds rules for dangerous goods. A few numbers worth knowing:

Item	Fire separation
Oxidizers, organic peroxides, reactive materials	2 h (3.3.6.2.)
Flammable compressed gas cylinder room	2 h, gas-tight, on an exterior wall (3.3.6.3.)
Small room, max 3 heavier-than-air cylinders, 100 kg	45 min, gas-tight, at or above grade
Tire storage over 375 m²	2 h (3.3.6.5.)

Cylinder rooms are vented mechanically for at least one air change per hour, or by low and high louvres. Floors where dangerous goods are stored must be impermeable (OBC Div. B 3.3.6.7.).

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Exits: horizontal exits, revolving doors, hardware and fire escapes

Horizontal exits may make up no more than one half of the required exits from a floor area (OBC Div. B 3.4.1.6.). Each side must hold the occupants of both floor areas at 0.5 m² per person (1.5 m² per wheelchair user), with no steps, and any level change between sides is limited to 2,000 mm (OBC Div. B 3.4.6.10.).

Travel distance where more than one exit is required (OBC Div. B 3.4.2.5.):

Floor area	Max travel to at least one exit
High-hazard industrial	25 m
Business and personal services	40 m
Sprinklered throughout (not F1)	45 m
Other floor areas	30 m

Revolving doors must be collapsible, have hinged doors beside them with equal capacity, be used only at ground floor, sit at least 3 m from the foot of a stair, and count for no more than 45 persons (OBC Div. B 3.4.6.15.).

Door release hardware. A latching exit door needs a device across at least half the door width when it serves a floor area with an assembly occupancy over 100 persons, an exit stair door to a lobby or exterior in a building with more than 100 occupants, or a high-hazard industrial floor area. Electromagnetic locks without latches are allowed on exit doors only with a fire alarm system and a long list of release conditions, including a manual station within 600 mm of the door and a sign reading "emergency exit unlocked by fire alarm" (OBC Div. B 3.4.6.16.).

Fire escapes are not erected on buildings, except on existing buildings where other exits are impracticable: up to 5 storeys above ground (2 in care, care and treatment or detention occupancies), never in schools or retirement homes (OBC Div. B 3.4.7.1.). Stairs are at most 45°, risers no more than 210 mm, treads at least 220 mm, and guards at least 920 mm (OBC Div. B 3.4.7.5., 3.4.7.6.).

Worked example

An unsprinklered 2-storey office (Group D) has two exits per floor. What is the maximum travel distance to at least one exit? Clause 3.4.2.5.(1)(b) gives 40 m for a business and personal services occupancy. If the building were sprinklered throughout, Clause (c) would allow 45 m. The 30 m in Clause (f) applies to occupancies not listed, such as an unsprinklered store.

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Elevators and vertical service spaces

Passenger elevators follow Appendix E of the elevator safety code named in OBC Div. B 3.5.2.2.. Hoistways are enclosed with a rating taken from Table 3.5.3.1. based on the floor assembly rating. For example, a 1 h floor gives a 1 h hoistway, and a 2 h floor gives 1.5 h. Elevator machine rooms match the hoistway (OBC Div. B 3.5.3.3.).

Other vertical service spaces use Table 3.6.3.1.: a 1 h floor needs only 45 min for the shaft. Refuse chute shafts need at least 1 h with a fusible-link closure at the outlet, or 2 h with none, and the chute discharges into a room with a 2 h separation (OBC Div. B 3.6.3.3.).

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Service rooms and plenums

A refuse and recycling storage room needs a 1 h fire separation (45 min where the floor is not required above 45 min) and must be sprinklered (OBC Div. B 3.6.2.5.). An electrical equipment vault required by the Electrical Safety Code is enclosed in masonry or concrete rated 3 h, or 2 h if it has an automatic extinguishing system (OBC Div. B 3.6.2.7.). A ceiling or roof space used as a plenum may skip the usual combustible-material limits if materials inside (with a few listed exceptions such as certain cables and raceways) have a flame-spread rating of not more than 25 and smoke developed of not more than 50, and ceiling supports melt no lower than 760°C (OBC Div. B 3.6.4.3.).

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Common traps

Using the hoistway table for a duct shaft. Table 3.5.3.1. is elevators and dumbwaiters, Table 3.6.3.1. is other shafts.
Applying 45 m travel distance to an unsprinklered floor area.
Forgetting the "first storey" limit on flammable liquid storage rooms.
Counting a revolving door for more than 45 persons.

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
Assembly separations, doors and storage rooms	The seating area of a Group A, Division 1 occupancy (theatres and similar) is separated from the rest of the floor area by a 1 h fire separation once seating occupant load exceeds…
Hazardous areas, exhaust and welding	Where dust, fumes or vapours could cause fire or explosion, an exhaust system designed to Part 6 is required, and explosion venting is required where the principal use creates an…
Exits: horizontal exits, revolving doors, hardware and fire escapes	Horizontal exits may make up no more than one half of the required exits from a floor area.
Elevators and vertical service spaces	Other vertical service spaces use: a 1 h floor needs only 45 min for the shaft.
Service rooms and plenums	A refuse and recycling storage room needs a 1 h fire separation (45 min where the floor is not required above 45 min) and must be sprinklered.

Assembly separations, doors and storage rooms
The seating area of a Group A, Division 1 occupancy (theatres and similar) is separated from the rest of the floor area by a 1 h fire separation once seating occupant load exceeds…
Hazardous areas, exhaust and welding
Where dust, fumes or vapours could cause fire or explosion, an exhaust system designed to Part 6 is required, and explosion venting is required where the principal use creates an…
Exits: horizontal exits, revolving doors, hardware and fire escapes
Horizontal exits may make up no more than one half of the required exits from a floor area.
Elevators and vertical service spaces
Other vertical service spaces use: a 1 h floor needs only 45 min for the shaft.
Service rooms and plenums
A refuse and recycling storage room needs a 1 h fire separation (45 min where the floor is not required above 45 min) and must be sprinklered.

Usual exam traps

Using the hoistway table for a duct shaft. Table 3.5.3.1. is elevators and dumbwaiters, Table 3.6.3.1. is other shafts.
Applying 45 m travel distance to an unsprinklered floor area.
Forgetting the "first storey" limit on flammable liquid storage rooms.
Counting a revolving door for more than 45 persons.

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Questions on Floor areas, exits, vertical transportation and service facilities, in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.

Practice this chapter Small Buildings calculations

Code cited in this chapter

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

OBC Div. B 3.3.1.4. Public Corridor Separations
(1)Except as otherwise required by this Part or as permitted by Sentence (4), a public corridor shall be separated from the remainder of the storey by a fire separation.
(2)Except as permitted by Sentence (3) and Clauses (4)(a) and (b), the fire separation between a public corridor and the remainder of the storey shall have a fire-resistance rating not less than 45 min.
(3)If a storey is sprinklered throughout, no fire-resistance rating is required for a fire separation between a public corridor and the remainder of the storey, provided the corridor does not serve a care, care and treatment, detention or residential occupancy. (See Note A-3.1.8.1.(1)(b))
(4)No fire separation is required in a sprinklered floor area between a public corridor and
(a)except as required by Sentences 3.3.3.5.(9) and 3.3.4.2.(1) and notwithstanding Sentence 3.4.2.4.(2), the remainder of a storey, provided the travel distance from any part of the floor area to an exit is not more than 45 m.,
(b)a room or suite, provided the public corridor complies with Sentence 3.3.1.9.(4) and Clause 3.4.2.5.(1)(d), or
(c)a space containing plumbing fixtures required by Subsection 3.7.4. provided the space and the public corridor are separated from the remainder of the storey by a fire separation having a fire-resistance rating not less than that required between the public corridor and the remainder of the storey.
Open OBC Div. B 3.3.1.4. in the code viewer
OBC Div. B 3.3.1.5. Egress Doorways
(1)Except for dwelling units, a minimum of 2 egress doorways located so that one doorway could provide egress from the room or suite as required by Article 3.3.1.3. if the other doorway becomes inaccessible to the occupants due to a fire that originates in the room or suite, shall be provided for every room and every suite
(a)whose area is more than 15 m² and is used for
(i)a high-hazard industrial occupancy, or
(ii)a hazardous room,
(b)intended for an occupant load more than 60,
(c)in a floor area that is not sprinklered throughout and
(i)the area of a room or suite is more than the value in Table 3.3.1.5.-A, or
(ii)the travel distance within the room or suite to the nearest egress doorway, is more than the value in Table 3.3.1.5.-A,
(d)in a floor area that is sprinklered throughout and does not contain a high-hazard industrial occupancy and
(i)the travel distance to an egress doorway is more than 25 m, or
(ii)the area of the room or suite is more than the value in Table 3.3.1.5.-B, or
(e)where the area of the room is more than 100 m² and it is a hazardous classroom in elementary or secondary school.
(2)Where 2 egress doorways are required by Sentence (1), they shall be placed at a distance from one another equal to or greater than one third of the maximum overall diagonal dimension of the area to be served, measured as the shortest distance that smoke would have to travel between the nearest required egress doors.
(3)Every room containing an assembly occupancy serving a hotel, and located in the building containing the hotel, shall be provided with no fewer than
(a)three separate egress doorways from the room where the occupant load is more than 600 persons, and
(b)four separate egress doorways from the room where the occupant load is more than 1,000 persons
(4)Each egress doorway in Sentence (3) shall be considered as contributing not more than,
(a)one-third of the required width where three egress doorways are required, and
(b)one-fourth of the required width where four egress doorways are required.
Open OBC Div. B 3.3.1.5. in the code viewer
OBC Div. B Table 3.3.1.5-A. Egress in Floor Area Not Sprinklered Throughout
Table 3.3.1.5.-A — Egress in Floor Area Not Sprinklered Throughout Forming Part of Sentence 3.3.1.5.(1) Occupancy of Room or Suite | Maximum Area of Room or Suite, m² | Maximum Distance to Egress Doorway, m Group A | 150 | 15 Group C | 100[1] | 15[1] Group D | 200 | 25 Group E | 150 | 15 Group F, Division 2 | 150 | 10 Group F, Division 3 | 200 | 15 Notes to Table 3.3.1.5.-A: (1) See Article 3.3.4.4. for dwelling units.
Open OBC Div. B Table 3.3.1.5-A. in the code viewer
OBC Div. B Table 3.3.1.5-B. Egress in Floor Area Sprinklered Throughout
Table 3.3.1.5.-B — Egress in Floor Area Sprinklered Throughout Forming Part of Sentence 3.3.1.5.(1) Occupancy of Room or Suite | Maximum Area of Room or Suite, m² Group A | 200 Group B, Division 1 | 100 Group B, Division 2 or 3 sleeping rooms | 100 Group B, Division 2 or 3 other than sleeping rooms | 200 Group C | 150[1] Group D | 300 Group E | 200 Group F, Division 2 | 200 Group F, Division 3 | 300 Notes to Table 3.3.1.5.-B: (1) See Article 3.3.4.4. for dwelling units.
Open OBC Div. B Table 3.3.1.5-B. in the code viewer
OBC Div. B 3.3.1.9. Corridors
(1)The minimum width of a public corridor shall be 1,100 mm.
(2)Except as required by Sentences 3.3.3.3.(2) and (3), the minimum unobstructed width shall be 1,100 mm for every
(a)corridor used by the public,
(b)corridor serving classrooms, and
(c)corridor in a Group B, Division 2 or 3 occupancy where the corridor
(i)serves a service room,
(ii)serves an administrative area,
(iii)will not be used by non-ambulatory outpatients, or
(iv)will not be used by non-ambulatory residents.
(3)If a corridor contains an occupancy, the occupancy shall not reduce the unobstructed width of the corridor to less than its required width.
(4)If a public corridor conforming to Clause 3.4.2.5.(1)(d) contains an occupancy,
(a)the occupancy shall be located so that for pedestrian travel there is an unobstructed width not less than 3 m at all times adjacent and parallel to all rooms and suites that front onto the public corridor, and
(b)the combined area of all occupancies in the public corridor shall be not more than 15% of the area of the public corridor.
(5)Except as provided in Sentence 3.3.3.3.(1), a dead-end corridor shall conform to Sentences (6) to (12).
(6)A dead-end corridor is permitted in an assembly occupancy where there is a second and separate egress doorway from each room or suite not leading into a dead-end corridor.
(7)Except as provided in Sentence 3.3.4.11.(10) and except for corridors served by a single exit as described in Sentence 3.3.4.4.(6), a dead-end public corridor is permitted in a residential occupancy provided it is not more than 6 m long.
(8)Dead-end corridors in Sentence (7) shall contain no door openings to service rooms containing fuel-fired appliances or rooms that may be considered a hazard.
(9)A dead-end public corridor is permitted in a business and personal services occupancy where
(a)the dead-end corridor
(i)serves an occupant load of not more than 30 persons,
(ii)is not more than 9 m long, and
(iii)is provided with doors having self-closing devices, or
(b)there is a second and separate egress doorway from each room or suite not leading into a dead-end corridor.
(10)A dead-end corridor is permitted in a mercantile occupancy where
(a)the dead-end corridor
(i)serves an occupant load of not more than 30 persons,
(ii)is not more than 9 m long, and
(iii)is provided with doors having self-closing devices, or
(b)there is a second and separate egress doorway from each room or suite not leading into a dead-end corridor.
(11)A dead-end corridor is permitted in a low- or medium-hazard industrial occupancy where
(a)the dead-end corridor
(i)serves an occupant load of not more than 30 persons,
(ii)is not more than 9 m long, and
(iii)is provided with doors having self-closing devices, or
(b)there is a second and separate egress doorway from each room or suite not leading into a dead-end corridor.
(12)A dead-end corridor is permitted in a high-hazard industrial occupancy where there is a second and separate egress doorway from each room or suite not leading into a dead-end corridor.
Open OBC Div. B 3.3.1.9. in the code viewer
OBC Div. B 3.3.1.22. Janitors' Rooms
(1)Except as permitted by Sentences (2) and (3), a room or space within a floor area for the storage of janitorial supplies shall be separated from the remainder of the building by a fire separation having a fire-resistance rating not less than 1 h.
(2)The fire-resistance rating of the fire separation required by Sentence (1) is permitted to be less than 1 h but not less than 45 min provided the fire-resistance rating required by Subsection 3.2.2. is permitted to be less than 1 h for
(a)the floor assembly above the floor area, or
(b)the floor assembly below the floor area, if there is no floor assembly above.
(3)The fire separation required by Sentence (1) is not required to have a fire-resistance rating if the floor area in which the room or space is located is sprinklered throughout.
Open OBC Div. B 3.3.1.22. in the code viewer
OBC Div. B 3.3.2.2. Fire Separations
(1)Except as permitted by Sentence (2), the seating area of a Group A, Division 1 occupancy shall be separated from adjacent occupancies in the floor area by a fire separation having a fire-resistance rating not less than 1 h if the occupant load in the seating area exceeds 200.
(2)The fire-resistance rating of the fire separation required by Sentence (1) is permitted to be less than 1 h but not less than 45 min provided the fire-resistance rating required by Subsection 3.2.2. is permitted to be less than 1 h for
(a)the floor assembly above the floor area, or
(b)the floor assembly below the floor area, if there is no floor assembly above.
(3)If usable space exists under tiers of seats in arena-type buildings, a fire separation with a fire-resistance rating not less than 45 min shall be provided between the space and the seats or the space shall be sprinklered.
(4)Except as required in Sentences (5) to (7), in an elementary or secondary school, a hazardous classroom shall be separated from the remainder of the building by a fire-separation having a fire-resistance rating not less than
(a)1 h where the building is not sprinklered, or
(b)30 min where the building is sprinklered throughout.
(5)Except as provided in Sentence (6), in an elementary or secondary school, a hazardous classroom containing an auto repair shop shall be separated from the remainder of the building by a fire-separation having a fire-resistance rating not less than
(a)2 h where the building is not sprinklered, or
(b)1 h where the building is sprinklered throughout.
(6)In an elementary or secondary school, if there is a group of hazardous classrooms or a group of hazardous classrooms and ancillary rooms of a complementary use, the fire separation required by Sentence (4) or (5) need not be provided within the group but the fire separation is required between the group and the remainder of the building.
(7)In an elementary or secondary school, a hazardous classroom containing a spray painting operation shall be separated from the remainder of the building by a fire separation having a fire-resistance rating not less than
(a)2 h, or
(b)1 h where the spray painting operation is separated from the classroom by a fire-separation having a fire-resistance rating not less than 1 h.
(8)Except as required in Sentence (9), in an elementary or secondary school, where the occupant load of a room exceeds 200 persons, the room and any ancillary rooms of a complementary use shall be separated from the remainder of the building by a fire separation having a fire-resistance rating not less than
(a)1 h where the building is not sprinklered, or
(b)30 min where the building is sprinklered throughout.
(9)A kitchen shall not be located within the fire compartment required in Sentence (8).
Open OBC Div. B 3.3.2.2. in the code viewer
OBC Div. B 3.3.2.7. Doors
(1)A door equipped with a latching mechanism in an access to exit from a room or suite of assembly occupancy containing an occupant load more than 100 shall be equipped with a device that complies with Sentence 3.4.6.16.(3).
Open OBC Div. B 3.3.2.7. in the code viewer

Show all 31 articles

OBC Div. B 3.3.2.16. Storage Rooms
(1)A room intended for the storage of flammable liquids or combustible liquids required by the Fire Code made under the Fire Protection and Prevention Act, 1997 shall not be located above or below the first storey of the building.
Open OBC Div. B 3.3.2.16. in the code viewer
OBC Div. B 3.3.1.21. Exhaust Ventilation and Explosion Venting
(1)Except as provided in Sentence (2), an exhaust ventilation system designed in conformance with the appropriate requirements of Part 6 shall be provided in a building or part of a building in which dust, fumes, gases, vapour or other impurities or contaminants have the potential to create a fire or explosion hazard. (See also Article 4.2.4.13.)
(2)Where a fire separation required to have a fire-resistance rating is penetrated by a ventilation system required by Sentence (1) for power-ventilated enclosures in laboratories, the ducts shall be
(a)continuously enclosed from the first penetrated fire separation to any subsequent fire separations or concealed spaces and all the way through to the outdoors so that the highest fire-resistance rating of all the penetrated fire separations is maintained, and
(b)exempted from the requirement to be equipped with a fire damper, smoke damper and combination smoke/fire damper as stated in Article 3.1.8.7.
(3)Explosion relief devices, vents or other protective measures conforming to Subsection 6.3.1. and Article 6.9.1.2. shall be provided for a space in which substances or conditions that have the potential to create an explosion hazard are present as a result of the principal use of a building.
Open OBC Div. B 3.3.1.21. in the code viewer
OBC Div. B 3.3.1.26. Welding and Cutting
(1)Except as provided in Sentence (2), welding and cutting operations shall be carried out in a room
(a)separated from the remainder of the building by a fire separation having a fire-resistance rating not less than 1 h, or
(b)protected by an automatic fire extinguishing system.
(2)Sentence (1) shall not apply to industrial occupancies where the welding and cutting operations do not present a fire or explosion hazard to adjacent areas.
Open OBC Div. B 3.3.1.26. in the code viewer
OBC Div. B 3.3.6.2. Storage of Dangerous Goods
(1)Solid and liquid dangerous goods classified as oxidizers or organic peroxides shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 2 h.
(2)Reactive materials shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 2 h. (See Note A-3.3.6.2.(2))
(3)The design and construction of buildings or part of a building intended for the storage of dangerous goods classified as explosives shall conform to the Explosives Act (Canada) and the regulations made under that Act.
Open OBC Div. B 3.3.6.2. in the code viewer
OBC Div. B 3.3.6.3. Indoor Storage of Compressed Gases
(1)Except as provided by Sentence (3), where required by the Fire Code made under the Fire Protection and Prevention Act, 1997, a room intended for the indoor storage of cylinders containing flammable compressed gases shall meet the following requirements:
(a)it is separated from the remainder of the building by a gas-tight fire separation having a fire-resistance rating of not less than 2 h,
(b)it is located on an exterior wall of the building,
(c)it can be entered from the exterior,
(d)it is ventilated in conformance with Sentence (4),
(e)it is constructed so that an exterior wall provides explosion venting
(i)in the ratio of 0.2 m² for each cubic metre of room volume, or
(ii)in the ratio computed in accordance with NFPA 68, "Standard on Explosion Protection by Deflagration Venting," but in no case less than 0.065 m² of vent area for each cubic metre of room volume,
(f)it is not intended to contain fuel-fired equipment or high temperature heating elements, and
(g)it is not intended to be used for a purpose other than the storage of compressed gas.
(2)Where a closure is installed in the fire separation separating the room from the remainder of the building in accordance with Clause (1)(a), it shall be
(a)equipped with a self-closing device that keeps the closure closed when not in use, and
(b)constructed so as to prevent the migration of gases from the room into other parts of the building.
(3)Where required by the Fire Code made under the Fire Protection and Prevention Act, 1997, a room intended for the storage of not more than three cylinders of flammable compressed gases that are heavier than air and that have an aggregate capacity not exceeding 100 kg shall be
(a)separated from the remainder of the building by a gas-tight fire separation having a fire-resistance rating of not less than 45 min,
(b)located at or above grade, and
(c)ventilated in conformance with Sentence (4).
(4)A room described in Sentence (1) or (3) shall be
(a)mechanically vented to the outside so as to ensure at least one air change per hour, or
(b)naturally vented to the outside so as to ensure cross ventilation through non-closable louvered openings with
(i)at least one opening having an aggregate free opening area of at least 0.2 m² per 100 m² of the floor area located not more than 300 mm from the ceiling, and
(ii)at least one opening having an aggregate free opening area of at least 0.2 m² per 100 m² of the floor area located not more than 300 mm from the floor.
(5)Except as permitted by Sentences (6) and (7), where required by the Fire Code made under the Fire Protection and Prevention Act, 1997, an area intended for the storage of cylinders containing compressed gases that may react with one another shall be divided into separate fire compartments having a fire-resistance rating of not less than 1 h.
(6)Separate fire compartments required by Sentence (5) need not be provided, if the area intended for the storage of cylinders containing compressed gases that are lighter than air is separated by a concrete or masonry wall having a height of at least 2.0 m and projecting at least 1.0 m, measured horizontally, beyond the cylinders.
(7)Separate fire compartments required by Sentence (5) need not be provided, if the area intended for the storage of cylinders containing compressed gases that are heavier than air is separated by a concrete or masonry wall having a height of at least 1.5 m and projecting such that the minimum distance that vapour can travel between two cylinders of gas that may react with each other is not less than 15 m, measured horizontally.
Open OBC Div. B 3.3.6.3. in the code viewer
OBC Div. B 3.3.6.5. Tire Storage
(1)A tire storage area intended for the storage of more than 375 m² of tires shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 2 h. (See Note A-3.3.6.5.(1))
Open OBC Div. B 3.3.6.5. in the code viewer
OBC Div. B 3.3.6.7. Flooring Materials
(1)Floors in areas where dangerous goods are stored shall be constructed of impermeable materials to prevent the absorption of chemicals.
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OBC Div. B 3.4.1.6. Restricted Use of Horizontal Exits
(1)Except as permitted by Sentence (2), horizontal exits shall not comprise more than one-half of the required number of exits from any floor area.
(2)In a hospital or long-term care home, horizontal exits serving patients' or residents' sleeping rooms shall comprise not more than two-thirds of the required number of exits from any floor area. (See Note A-3.4.1.6.(2))
(3)Where an elementary or secondary school is subdivided by a firewall, a horizontal exit shall not serve as an exit but is permitted to serve as an access to exit.
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OBC Div. B 3.4.6.10. Horizontal Exits
(1)Except in an elementary or secondary school that is subdivided by a firewall, the floor area on each side of a horizontal exit shall be sufficient to accommodate the occupants of both floor areas, allowing not less than 0.5 m² of clear floor space per person, except that 1.5 m² shall be provided for each person in a wheelchair and 2.5 m² for each bedridden patient.
(2)If vestibules, enclosed balconies or bridges are used as parts of a horizontal exit, their clear width shall be not less than that of the exit doorways opening into them, except that handrails are not permitted to project into this clear width more than 100 mm.
(3)In a horizontal exit where there is a difference in level between the connected floor areas, slopes not more than those specified for ramps in Article 3.4.6.7. are permitted to be used.
(4)No stairs or steps shall be used at a horizontal exit.
(5)If 2 doors are provided in a horizontal exit that comprises a part of the required number of exits from the floor areas on both sides of the exit
(a)the doors shall be mounted adjacent to each other with the door on the right side in the direction of travel through the horizontal exit swinging in the direction of travel through the horizontal exit, and
(b)signs shall be provided on each side of the horizontal exit to indicate the door that swings in the direction of travel from that side. (See Note A-3.4.6.10.(5))
(6)If a horizontal exit utilizes bridges between buildings or outside balconies, the bridges or balconies shall conform to Article 3.2.3.19.
(7)Any change in floor level from one side of a horizontal exit to the other side shall not exceed 2,000 mm.
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OBC Div. B 3.4.2.5. Location of Exits
(1)Except as permitted by Sentences (2) and 3.3.2.5.(13) to (16), if more than one exit is required from a floor area, the exits shall be located so that the travel distance to at least one exit shall be not more than
(a)25 m in a high-hazard industrial occupancy,
(b)40 m in a business and personal services occupancy,
(c)45 m in a floor area that contains an occupancy other than a high-hazard industrial occupancy, provided it is sprinklered throughout,
(d)105 m in any floor area, served by a public corridor, in which rooms and suites are not separated from the remainder of the floor area by a fire separation, provided
(i)the public corridor is not less than 9 m wide,
(ii)the ceiling height in the public corridor is not less than 4 m above all floor surfaces,
(iii)the building is sprinklered throughout, and
(iv)not more than one-half of the required egress doorways from a room or suite open into the public corridor if the room or suite is required to have more than one egress doorway,
(e)60 m in any storage garage that conforms to the requirements of Article 3.2.2.92., and
(f)30 m in any floor area other than those referred to in Clauses (a) to (e).
(2)Except for a high-hazard industrial occupancy, Sentence (1) need not apply if exits are placed along the perimeter of the floor area and are not more than 60 m apart, measured along the perimeter, provided each main aisle in the floor area leads directly to an exit.
(3)Exits shall be located and arranged so that they are clearly visible or their locations are clearly indicated and they are accessible at all times.
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OBC Div. B 3.4.6.15. Revolving Doors
(1)Except as permitted by Sentence (3), a revolving door, if used, shall
(a)be collapsible,
(b)have hinged doors providing equivalent exiting capacity located adjacent to it,
(c)be used as an exit from the ground floor level only,
(d)be not less than 3 m from the foot of any stairway, and
(e)have all glass in door leaves and enclosure panels conforming to
(i)CAN/CGSB-12.1, "Safety Glazing," or
(ii)CAN/CGSB-12.11-M, "Wired Safety Glass."
(2)Except as permitted by Sentence (3), a revolving door shall not be considered to have an exiting capacity for more than 45 persons.
(3)An electrically powered revolving door is not required to conform to Sentences (1) and (2) provided
(a)the door leaves will collapse and stop automatic rotation of the door system and not obstruct the doorway if a force not more than that specified in Sentence 3.4.6.16.(2) is applied at the centre of a door leaf,
(b)the door leaves are capable of being opened from inside the building without requiring keys, special devices, or specialized knowledge of the door opening mechanism,
(c)the allowable exiting capacity is based on the clear width of passage through the door enclosure when the doors are fully collapsed,
(d)a permanent sign, whose centre line is between 1,000 mm and 1,500 mm above the floor, is placed on each face of each door leaf indicating the method for collapsing the door leaf in an emergency, and
(e)glass used for door leaves and enclosure panels is safety glazing conforming to
(i)CAN/CGSB-12.1, "Safety Glazing," or
(ii)CAN/CGSB-12.11-M, "Wired Safety Glass."
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OBC Div. B 3.4.6.16. Door Release Hardware
(1)Except for dwelling units, except for devices on doors serving a contained use area or an impeded egress zone designed to be released in conformance with Article 3.3.1.13., and except as permitted by Sentence (5), locking, latching and other fastening devices on every exit door shall permit the door to be readily opened from the inside with not more than one releasing operation and without requiring keys, special devices or specialized knowledge of the door opening mechanism. (See Note A-3.4.6.16.(1))
(2)If a door is equipped with a latching mechanism, a device complying with Sentence (3) shall be installed on
(a)every exit door from a floor area containing an assembly occupancy having an occupant load more than 100,
(b)every door leading to an exit lobby from an exit stair shaft, and every exterior door leading from an exit stair shaft in a building having an occupant load more than 100, and
(c)every exit door from a floor area containing a high-hazard industrial occupancy.
(3)The device required in Sentence (2) shall
(a)extend across not less than one-half of the width of the door,
(b)release the latch, and
(c)allow the door to swing wide open when a force not more than that specified in Sentence 3.8.3.3.(7) is applied to the device in the direction of travel to the exit.
(4)Except as required by Sentence 3.8.3.3.(7), every exit door shall be designed and installed so that, when the latch is released, the door will open under a force of not more than 90 N, applied at the knob or other latch releasing device.
(5)Except as permitted by Sentence 3.3.1.13.(6), electromagnetic locks that do not incorporate latches, pins or other similar devices to keep the door in the closed position are permitted to be installed on exit doors other than doors described in Sentence (6) provided
(a)the building is equipped with a fire alarm system conforming to Subsection 3.2.4.,
(b)the locking device, and all similar devices in the access to exit leading to the exit door, are installed as ancillary devices to the fire alarm system and release immediately upon activation of
(i)the alarm signal where a single-stage fire alarm system is installed,
(ii)except as provided in Subclause (iii), the alert signal where a 2-stage fire alarm system is installed, or
(iii)the alarm signal of a 2-stage fire alarm system installed in a care, care and treatment or detention occupancy or in a retirement home,
(c)the locking device releases immediately upon loss of power controlling the electromagnetic locking mechanism and its associated auxiliary controls,
(d)the locking device releases immediately upon actuation of a manually operated switch readily accessible only to authorized personnel and located near the main entrance of the building or in the central alarm and control facility of Sentence 3.2.6.7.(1),
(e)the locking device releases immediately upon a fault being detected in the electrical circuit between the fire alarm control panel and the controller of the locking device,
(f)the locking device releases immediately upon the operation of a manual station for the fire alarm system located on the wall not more than 600 mm from the door,
(g)a visual information sign complying with Article 3.8.3.1. that displays the words emergency exit unlocked by fire alarm is permanently mounted on the door,
(h)a tactile information sign complying with Article 3.8.3.1. that displays the words emergency exit unlocked by fire alarm is permanently mounted near the door,
(i)upon release, the locking device must be reset manually by the actuation of the switch referred to in Clause (d),
(j)the operation of any by-pass switch, where provided for testing of the fire alarm system, causes an audible signal and a visual signal to be indicated at the fire alarm annunciator panel and at the monitoring station referred to in Sentence 3.2.4.8.(4),
(k)emergency lighting conforming to 3.2.7.3.(1) is provided, and
(l)where they are installed on doors providing emergency crossover access to floor areas from exit stairs in accordance with Article 3.4.6.18.,
(i)the locking device releases immediately upon the operation of a manual station for the fire alarm system located on the wall on the exit stair side not more than 600 mm from the door,
(ii)a visual information sign displaying the words re-entry door unlocked by fire alarm that complies with Article 3.8.3.1. is permanently mounted on the door on the exit stair side, and
(iii)a tactile information sign displaying the words re-entry door unlocked by fire alarm that complies with Article 3.8.3.1. is permanently mounted near the door on the exit stair side. (See Note A-3.4.6.16.(5))
(6)Reserved.
(7)Door release hardware for the operation of the doors referred to in this Section shall be installed between 900 mm and 1,100 mm above the finished floor.
(8)Except as permitted by Sentences (9) and (10), electromagnetic locks are not permitted to be installed on exit doors
(a)described in Clause (2)(a),
(b)or
(c)
(b) serving an elementary or secondary school, or
(c) leading directly from a high-hazard industrial occupancy.
(9)Electromagnetic locks are permitted to be installed on an exterior door leading from an exit stairway in a building containing only a Group B, Division 2 major occupancy, a Group B, Division 3 major occupancy or a retirement home.
(10)Electromagnetic locks are permitted to be installed on an exit door that serves only a gaming premises if
(a)the gaming premises is located within a sprinklered floor area,
(b)smoke detectors are installed in each room and each corridor accessible to the public,
(c)a force of not more than 90 N applied to the door opening hardware initiates an irreversible process that will release the locking device within 15 s and not relock until the door has been opened, and
(d)a legible sign conforming with Clauses (5)(g) and(h) is permanently mounted on the exit door to indicate that the locking device will release within 15 s of applying pressure to the door release hardware.
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OBC Div. B 3.4.7.1. Scope
(1)Except as permitted by Sentence (2), fire escapes shall not be erected on a building.
(2)If it is impracticable to provide one or more of the exit facilities listed in Article 3.4.1.4., fire escapes conforming to Articles 3.4.7.2. to 3.4.7.7. are permitted to serve floor areas in an existing building provided the floor areas served are
(a)not in an elementary or secondary school or a retirement home,
(b)not more than 2 storeys above ground level in care, care and treatment or detention occupancies, and
(c)not more than 5 storeys above ground level in other occupancies.
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OBC Div. B 3.4.7.5. Stairs
(1)Stairs shall be inclined at an angle of not more than 45° with the horizontal, and their steps shall have risers not more than 210 mm high and treads not less than 220 mm wide exclusive of nosing.
(2)Stairway headroom shall be not less than 1,950 mm plus the height of one riser measured vertically above the nosing of any tread or platform.
(3)The width of a fire escape shall conform to Articles 3.4.3.1. to 3.4.3.3., except that the width is permitted to be reduced to 550 mm provided the fire escape serves
(a)not more than 3 storeys, and
(b)not more than 15 persons.
(4)If a flight of stairs leading to the ground at the foot of a fire escape is not fixed in position, it shall
(a)be held in the raised position without a latch or locking device,
(b)be fitted with a counterbalancing device,
(c)be easily and quickly brought into position for use, and
(d)reach the ground in the lowered position.
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OBC Div. B 3.4.7.6. Guards and Railings
(1)The open sides of every platform, balcony and stairway forming part of a fire escape shall be protected by guards not less than 920 mm high measured vertically above the nosing of any tread or platform.
(2)The top rail of a guard is permitted to serve as a handrail if it is free from obstructions that could break a handhold.
(3)A wall handrail shall be installed if the fire escape is more than 550 mm wide.
(4)Openings through any guard that is required by Sentence (1) shall be of a size that will prevent the passage of a sphere having a diameter more than 100 mm unless it can be shown that the location and size of openings that exceed this limit do not represent a hazard.
(5)Unless it can be shown that the location and size of an opening do not present a hazard, a guard for a fire escape shall be designed so that no member, attachment or opening located between 140 mm and 900 mm above a platform or the nosing of any tread will facilitate climbing.
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OBC Div. B 3.5.2.2. Barrier-Free Design
(1)Passenger elevators shall conform to Appendix E of ASME A17.1 / CSA B44, "Safety Code for Elevators and Escalators."
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OBC Div. B Table 3.5.3.1. Fire Separation for Vertical Transportation Space
Table 3.5.3.1 — Fire Separation for Vertical Transportation Space Forming Part of Sentences 3.5.3.1.(1) and 3.5.3.2.(1) Fire-Resistance Rating of Fire Separation Required for Floor Assembly | Minimum Fire-Resistance Rating of Vertical Service Space for Elevator Hoistway | Minimum Fire-Resistance Rating of Vertical Service Space for Dumbwaiters less than 45 min | 45 min | N/A 45 min | 45 min | 45 min 1 h | 1 h | 45 min 1.5 h | 1 h | 1 h 2 h or more | 1.5 h | 1 h
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OBC Div. B 3.5.3.3. Fire Separations for Elevator Machine Rooms
(1)Except as permitted by Sentence (2), a room containing elevator machinery shall be separated from all other parts of the building by a fire separation having a fire-resistance rating not less than that required for the vertical service space containing the elevator hoistway.
(2)A room containing elevator machinery need not be separated from the elevator hoistway that it serves provided the room and the hoistway are separated from all other parts of the building by a fire separation having a fire-resistance rating not less than that required for the vertical service space containing the elevator hoistway.
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OBC Div. B Table 3.6.3.1. Fire Separations for Vertical Service Space
Table 3.6.3.1 — Fire Separations for Vertical Service Space Forming Part of Sentence 3.6.3.1.(1) Fire-Resistance Rating of Fire Separation Required for Floor Assembly | Minimum Fire-Resistance Rating of Vertical Service Space less than 45 min | N/A 45 min | 45 min 1 h | 45 min 1.5 h | 1 h 2 h or more | 1 h
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OBC Div. B 3.6.3.3. Linen and Refuse Chutes
(1)A linen chute or refuse chute shall
(a)be impervious to moisture,
(b)have a smooth internal surface,
(c)be corrosion-resistant,
(d)be constructed of noncombustible material, and
(e)be located in a shaft in which there are no services other than noncombustible drain, waste and vent piping or noncombustible water piping.
(2)A shaft containing a linen chute or refuse chute shall have a fire-resistance rating conforming to Sentence 3.6.3.1.(1), but not less than
(a)1 h if the chute outlet for the discharge room is protected by an automatic, self-latching closure held open by a fusible link, or
(b)2 h if no closure is provided at the chute outlet into the discharge room.
(3)An interior linen chute or refuse chute shall extend not less than 1 m above the roof and shall be vented above the roof with a vent which
(a)has an unobstructed area not less than the cross-sectional area of the chute, and
(b)is equipped with a cover that will open automatically, or that can be opened manually, in the event of a fire in the
(4)Intake openings for a linen chute or a refuse chute shall
(a)have an area not more than 60% of the cross-sectional area of the chute, and
(b)be fitted with closures designed to close automatically and latch after use.
(5)Intake openings for a linen chute or a refuse chute shall be located in rooms or compartments that
(a)have no dimension less than 750 mm,
(b)are separated from the remainder of the building by a fire separation with a fire-resistance rating not less than 45 min,
(c)are designed for no other purpose, and
(d)do not open directly into an exit.
(6)Sprinklers shall be installed at the top of each linen chute or refuse chute, at alternate floor levels and in the room or bin into which the chute discharges.
(7)The room into which a linen chute discharges shall be separated from the remainder of the building by a fire separation with a fire-resistance rating not less than 1 h.
(8)A refuse chute shall be equipped at the top with spray equipment for washing-down purposes.
(9)A refuse chute shall discharge only into a room or bin separated from the remainder of the building by a fire separation with a fire-resistance rating not less than 2 h.
(10)The room or bin into which a refuse chute discharges shall be of sufficient size to contain the refuse between normal intervals of emptying, be impervious to moisture and be equipped with a water connection and floor drain for washing-down purposes.
(11)A room into which a refuse chute discharges shall contain no service equipment that is not related to refuse handling and disposal.
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OBC Div. B 3.6.2.5. Storage of Combustible Refuse and Recycling
(1)Except as required by Sentence 3.6.3.3.(9), a room for the temporary storage of combustible refuse and materials for recycling shall be
(a)separated from the remainder of the building by a fire separation with a fire-resistance rating not less than 1 h, except that a fire separation with a fire-resistance rating not less than 45 min is permitted where the fire-resistance rating of the floor assembly is not required to exceed 45 min, and
(b)sprinklered. (See Note A-3.6.2.5.(1))
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OBC Div. B 3.6.2.7. Electrical Equipment Vaults
(1)Where an electrical equipment vault is required by the Electrical Safety Code adopted under Ontario Regulation 164/99 (Electrical Safety Code) made under the Electricity Act, 1998, the electrical equipment vault shall be totally enclosed by a fire separation of solid masonry or concrete construction having a fire-resistance rating of not less than 3 h if the vault is not provided with an automatic fire extinguishing system and not less than 2 h if the vault is so protected.
(2)Where a building is required to be sprinklered throughout, the electrical equipment vault described in Sentence (1) need not be sprinklered provided
(a)the vault is designed for no purpose other than to contain the electrical equipment, and
(b)a smoke detector is provided in the vault that will actuate the building fire alarm system in the event of a fire in the vault.
(3)A vault, that is part of a building and houses electrical equipment indoors, shall have
(a)roofs or ceilings consisting of reinforced concrete of adequate strength for the conditions and not less than 150 mm thick, and
(b)floors consisting of reinforced concrete of adequate strength for the conditions and not less than 150 mm thick, except that floors that are at excavation level are permitted to be of reinforced concrete not less than 100 mm thick.
(4)Walls, roofs or ceilings, and floors shall be adequately anchored together in a manner designed to resist dislodgement by explosion.
(5)Only pipes or ducts necessary for fire protection or the proper operation of the electrical installation shall penetrate the fire separations surrounding the electrical equipment vault.
(6)A ventilation duct or opening, that penetrates the fire separation to the outdoors, need not be protected by a closure at the penetration.
(7)Each door to an electrical equipment vault shall be provided with a substantial lock or padlock.
(8)Explosion-relief devices and vents or other protective measures shall be provided for every electrical equipment vault containing dielectric liquid-filled electrical equipment in conformance with Sentence 3.3.1.21.(3). (See Note A-3.6.2.7.(8))
(9)Every electrical equipment vault shall be provided with a ventilation system designed in conformance with Part 6 to prevent the ambient temperature in the vault from exceeding 40 ° C.
(10)Where the vault ventilation system in Sentence (9) is directly from an outdoor area by natural ventilation without the use of ducts, and where the electrical equipment is the principal source of heat, the combined net area of inlet and outlet openings shall be not less than 0.002 m² / kVa of electrical equipment capacity with a minimum of 0.093 m² , except that
(a)where equipment in the power class as described in CAN/CSA-C88-M, "Power Transformers and Reactors" is installed, ventilation requirements are permitted to be based on the actual full-load losses, or
(b)where the equipment is installed for emergency purposes only and is not normally energized, it need not be considered in determining the ventilation requirements.
(11)In the vault ventilation system in Sentence (10), the inlet for fresh air shall lead from an outdoor area and shall terminate at a point not more than 1,000 mm above the floor level of the vault.
(12)Where the vault ventilation system in Sentence (9) is a mechanical system, it shall be separate from the system for the remainder of the building and shall be designed so that
(a)the vault temperature is thermostatically controlled,
(b)the fan is located so that it may be serviced without danger to personnel,
(c)a high temperature alarm is provided in the vault,
(d)the system is automatically shut off in the event of a fire in the vault, and
(e)a filter is provided in the air inlet if there is a possibility of dirt being drawn in.
(13)All ventilation openings shall be protected in conformance with Sentences 6.3.2.9.(4) and (5) and the protection shall be installed in such a manner that it cannot be removed from the outside by the use of common tools and it is tamperproof.
(14)Except as permitted in Sentence (15), the floor of an electrical equipment vault referred to in Sentences (1) and (2) shall be liquid tight and surrounded by liquid tight walls and sills of sufficient height to confine within the vault all of the liquid from the largest item of electrical equipment, but to a height of not less than 100 mm.
(15)The floor of the electrical equipment vault described in Sentences (1) and (2) may be provided with a floor drain connected to a covered sump capable of holding all of the liquid from the largest item of electrical equipment, and the connection shall have a noncombustible trap to prevent the spread of fire from the vault to the sump.
(16)Where the electrical equipment vault is located in a hazardous location classified as Class II, Division 1 in accordance with the Electrical Safety Code adopted under Ontario Regulation 164/99 (Electrical Safety Code) made under the Electricity Act, 1998, it shall have
(a)no vent opening except to the exterior of the building, and
(b)suitable pressure-relief openings communicating only with the air outside the building.
(17)Where doors are provided between the vault described in Sentence (16) and the rest of the building, they shall have suitable seals such as weatherstripping to minimize the entrance of dust into the vault.
(18)Every electrical equipment vault shall be provided with
(a)adequate lighting, controlled by one or more switches located near the entrance,
(b)luminaires located so that they may be relamped without danger to personnel, and
(c)a grounded receptacle located in a convenient location inside the vault, near the entrance.
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OBC Div. B 3.6.4.3. Plenum Requirements
(1)A concealed space used as a plenum within a floor assembly or within a roof assembly need not conform to Sentence 3.1.5.18.(1) and Article 3.6.5.1. provided
(a)all materials within the concealed space have a flame-spread rating not more than 25 and a smoke developed classification not more than 50, except for
(i)tubing for pneumatic controls,
(ii)optical fibre cables and electrical wires and cables with combustible insulation, jackets or sheathes that are used for the transmission of voice, sound or data and conform to Sentences 3.1.4.3.(2) and 3.1.5.21.(2),
(iii)totally enclosed non-metallic raceways with an FT6 rating, when tested in accordance with Clause 3.1.5.23.(1)(a), in buildings required to be of noncombustible construction or in buildings or parts of buildings permitted to be of encapsulated mass timber construction, and
(iv)totally enclosed non-metallic raceways with an FT4 rating, when tested in accordance with Clause 3.1.5.23.(1)(a), in buildings permitted to be of combustible construction, and,
(b)the supports for the ceiling membrane are of noncombustible material having a melting point not below 760°C.
(2)If a concealed space referred to in Sentence (1) is used as a return-air plenum and incorporates a ceiling membrane that forms part of the required fire-resistance rating of the assembly, every opening through the membrane shall be protected by a fire stop flap that
(a)stops the flow of air into the concealed space in the event of a fire,
(b)is supported in a manner that will maintain the integrity of the ceiling membrane for the duration of time required to provide the required fire-resistance rating,
(c)conforms to CAN/ULC-S112.2, "Standard Method Fire Test of Ceiling Firestop Flap Assemblies," and
(d)activates at a temperature approximately 30°C above the normal maximum temperature that occurs in the return-air plenum, whether the air duct system is operating or shut down.
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