OBC DIVISION B · PART 3 — FIRE PROTECTION, OCCUPANT SAFETY AND ACCESSIBILITYUpdated for the 2024 Ontario Building Code
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Section 3.1 — General
Full text of Section 3.1 (General) — Division B, Part 3 (Fire Protection, Occupant Safety and Accessibility) of the 2024 Ontario Building Code, with every article reproduced below.
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3.1.1.Scope and Definitions
3.1.1.1.Scope permalink →
(1) The scope of this Part shall be as described in Subsection 1.3.3. of Division A.
3.1.1.2.Defined Words permalink →
(1) Words that appear in italics are defined in Article 1.4.1.2. of Division A.
3.1.1.3.Reserved
3.1.1.4.Reserved
3.1.1.5.Radon permalink →
(1) In addition to all other requirements, a building in the following designated areas shall be designed and constructed
so that the annual average concentration of radon 222 does not exceed 200 Bq/m3 of air and the annual average
concentration of the short lived daughters of radon 222 does not exceed 0.02 working levels inside the building:
(a) the City of Elliot Lake in the Territorial District of Algoma,
(b) the Township of Faraday in the County of Hastings, and
(c) the geographic Township of Hyman in the Territorial District of Sudbury.
3.1.1.6.Building in Flood Plains permalink →
(1) Buildings constructed on flood plains shall
(a) be designed and constructed in accordance with good engineering practice to withstand anticipated vertical and
horizontal hydrostatic pressures acting on the structure, and
(b) incorporate floodproofing measures that will preserve the integrity of exits and means of egress during times of
flooding.
3.1.2.Classification of Buildings or Parts of Buildings by Major
3.1.2.1.Classification of Buildings permalink →
(1) Except as permitted by Articles 3.1.2.3. to 3.1.2.7., every building or part thereof shall be classified according to its
major occupancy as belonging to one of the Groups or Divisions described in Table 3.1.2.1. (See Note A-3.1.2.1.(1))
(2) A building intended for use by more than one major occupancy shall be classified according to all major
occupancies for which it is used or intended to be used.
Table 3.1.2.1.
Major Occupancy Classification
Forming Part of Sentences 3.1.2.1.(1), 3.1.2.2.(1) and 3.11.2.1.(3)
Group Division Description of Major Occupancies
A 1 Assembly occupancies intended for the production and viewing of the performing arts
A 2 Assembly occupancies not elsewhere classified in Group A
A 3 Assembly occupancies of the arena type
A 4 Assembly occupancies in which occupants are gathered in the open air
B 1 Detention occupancies
B 2 Care and treatment occupancies
B 3 Care occupancies
C --- Residential occupancies
D --- Business and personal services occupancies
E --- Mercantile occupancies
F 1 High-hazard industrial occupancies
F 2 Medium-hazard industrial occupancies
F 3 Low-hazard industrial occupancies
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.2.2.Occupancies of the Same Classification permalink →
(1) Any building is deemed to be occupied by a single major occupancy, notwithstanding its use for more than one
major occupancy, provided that all occupancies are classified as belonging to the same Group classification or, where the
Group is divided into Divisions, as belonging to the same Division classification described in Table 3.1.2.1.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.2.3.Arena-Type Buildings permalink →
e1 (1) An arena-type building intended for occasional use for trade shows and similar exhibition purposes shall be
classified as Group A, Division 3 occupancy.
3.1.2.4.Police Stations permalink →
(1) A police station with detention quarters is permitted to be classified as a Group B, Division 2 major occupancy
provided the station is not more than 1 storey in building height and 600 m2 in building area.
3.1.2.5.Group B, Division 3 Occupancies permalink →
(1) Group B, Division 3 occupancies are permitted to be classified as Group C major occupancies within the application
of Part 3 provided
(a) the occupants live as a single housekeeping unit in a suite with sleeping accommodation for not more than 10
persons, and
(b) not more than two occupants require assistance in evacuation in case of an emergency.
3.1.2.6.Storage of Combustible Fibres permalink →
(1) Buildings or parts of thereof used for the storage of baled combustible fibres shall be classified as medium-hazard
industrial occupancies.
3.1.2.7.Restaurants permalink →
(1) A restaurant is permitted to be classified as a Group E major occupancy within the application of Part 3 provided the
restaurant is designed to accommodate not more than 30 persons consuming food or drink.
3.1.3.Multiple Occupancy Requirements
3.1.3.1.Separation of Major Occupancies permalink →
(1) Except as permitted by Sentences (2) and (3), major occupancies shall be separated from adjoining major
occupancies by fire separations having fire-resistance ratings conforming to Table 3.1.3.1.
(2) In a building not more than 3 storeys in building height, if not more than two dwelling units are contained together
with a Group E major occupancy, the fire-resistance rating of the fire separation between the two major occupancies
need not be more than 1 h.
(3) In a building conforming to the requirements of Articles 3.2.8.2. to 3.2.8.8., the requirements of Sentence (1) for fire
separations between major occupancies do not apply at the vertical plane around the perimeter of an opening through the
horizontal fire separation.
r1 Table 3.1.3.1.
Major Occupancy Fire Separations(1)
Forming Part of Sentence 3.1.3.1.(1)
Minimum Fire-Resistance Rating of Fire Separation, h
Major Occupancy Adjoining Major Occupancy
A-1 A-2 A-3 A-4 B-1 B-2 B-3 C D E F-1 F-2 F-3
A-1 — 1 1 1 2 2 2 1 1 2 (2)
2 1
A-2 1 — 1 1 2 2 2 1(3) 1(4) 2 (2)
2 1
A-3 1 1 — 1 2 2 2 1 1 2 (2)
2 1
A-4 1 1 1 — 2 2 2 1 1 2 (2)
2 1
B-1 2 2 2 2 — 2 2 2 2 2 (2)
2 2
B-2 2 2 2 2 2 — 1 2 2 2 (2)
2 2
B-3 2 2 2 2 2 1 — 2 2 2 (2)
2 2
C 1 1(3) 1 1 2 2 2 — 1 2(5) (2)
2(6) 1
D 1 1(4) 1 1 2 2 2 1 — — 3 — —
E 2 2 2 2 2 2 2 2(5) — — 3 — —
F-1 (2) (2) (2) (2) (2) (2) (2) (2)
3 3 — 2 2
F-2 2 2 2 2 2 2 2 2(6) — — 2 — —
F-3 1 1 1 1 2 2 2 1 — — 2 — —
r1 Notes to Table 3.1.3.1.:
(1) Section 3.3. contains requirements for the separation of occupancies and tenancies that are in addition to the requirements for the
separation of major occupancies.
(2) See Sentence 3.1.3.2.(1).
(3) Where the building or part thereof is constructed in accordance with Article 3.2.2.51., a fire separation with a 2 h fire-resistance rating
is required between the Group C and Group A, Division 2 major occupancies.
(4) Where the building or part thereof is constructed in accordance with Article 3.2.2.60., a fire separation with a 2 h fire-resistance rating
is required between the Group D and Group A, Division 2 major occupancies.
(5) See Sentence 3.1.3.1.(2).
(6) See Sentence 3.1.3.2.(2).
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.3.2.Prohibition of Occupancy Combinations permalink →
(1) No major occupancy of Group F, Division 1 shall be contained within a building with any occupancy classified as
Group A, B or C.
(2) Except as provided in Sentence (4) and Sentence 3.10.2.4.(9), not more than one suite of residential occupancy shall
be contained within a building classified as a Group F, Division 2 major occupancy.
(3) A sleeping room or sleeping area shall not open directly into a room or area where food is intended to be stored,
prepared, processed, distributed, served, sold or offered for sale. (See Note A-3.1.3.2.(3))
(4) A Group F, Division 2 major occupancy is permitted in a building containing only live/work units if the occupancy
is for the exclusive use of the occupants of the live/work units.
(5) A building within the scope of Article 3.2.2.51. or 3.2.2.60. shall not contain a retirement home.
3.1.4.Combustible Construction
3.1.4.1.Combustible Materials Permitted permalink →
(1) A building permitted to be of combustible construction is permitted to be constructed of combustible materials, with
or without noncombustible components. (See Note A-3.1.4.1.(1))
3.1.4.2.Protection of Foamed Plastics (See Note A-3.1.4.2.) permalink →
(1) Except as permitted in Sentence (2), foamed plastics that form part of a wall or ceiling assembly in combustible
construction shall be protected from adjacent spaces in the building, other than adjacent concealed spaces within attic or
roof spaces, crawl spaces, and wall and ceiling assemblies,
(a) by one of the interior finishes described in Subsections 9.29.4. to 9.29.9.,
(b) provided the building does not contain a Group A, Group B or Group C major occupancy, by sheet metal
(i) mechanically fastened to the supporting assembly independent of the insulation,
(ii) not less than 0.38 mm thick, and
(iii) with a melting point not below 650°C, or
(c) any thermal barrier that meets the requirements of Sentence 3.1.5.15.(2). (See Note A-3.1.4.2.(1)(c))
(See Note A-3.1.4.2.(1))
(1.1) The flame-spread rating on any exposed surface of combustible insulation, or any surface that would be exposed by
cutting through it in any direction, shall be not more than 500.
(2) A walk-in cooler or freezer consisting of factory-assembled wall, floor or ceiling panels containing foamed plastics
is permitted to be used in a building permitted to be of combustible construction, provided the panels
(a) are protected on both sides by sheet metal not less than 0.38 mm thick having a melting point not less than 650°C,
(b) do not contain an air space, and
(c) when a sample panel with an assembled joint typical of field installation is subjected to the applicable test described
n Subsection 3.1.12., have a flame-spread rating not more than that permitted for the space in which they are
located, the space that they bound, as applicable.
(See Note A-3.1.4.2.(2) and 3.1.5.7.(3))
(3) The flame-spread rating of doors containing foamed plastics shall comply with Sentences 3.1.13.2.(1) to (3).
3.1.4.3.Wires and Cables permalink →
(1) Except as required by Sentence (2), optical fibre cables and electrical wires and cables with combustible insulation,
jackets or sheathes installed in a building permitted to be of combustible construction shall
(a) not convey flame or continue to burn for more than 1 min when tested in conformance with the Vertical Flame Test
(FT1 rating) in CSA C22.2 No. 0.3, “Test Methods for Electrical Wires and Cables,” or
(b) be located in
(i) totally enclosed noncombustible raceways, (See Note A-3.1.4.3.(1)(b)(i))
(ii) masonry walls,
(iii) concrete slabs, or
(iv) totally enclosed non-metallic raceways conforming to Clause 3.1.5.23.(1)(b).
(See Note A-3.1.4.3.(1)) (See also Sentence 3.6.4.3.(1))
(2) Except as permitted in Sentences (3) and (4), 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 are installed in a plenum in a
building permitted to be of combustible construction shall exhibit the following characteristics when tested in
conformance with CAN/ULC-S102.4, “Standard Method of Test for Fire and Smoke Characteristics of Electrical Wiring,
Cables and Non-Metallic Raceways,” (FT6 rating):
(a) a horizontal flame distance of not more than 1.5 m,
(b) an average optical smoke density of not more than 0.15, and
(c) a peak optical smoke density of not more than 0.5.
(3) Except as permitted in Sentence (4), where totally enclosed noncombustible raceways are used in a plenum, exposed
components of wiring systems with combustible insulation, jackets or sheathes, including optical fibre cables and
electrical wires and cables that are used for the transmission of voice, sound or data, that are installed in the plenum or
that extend not more than 9 m from the plenum, including drop down to the floor level, are permitted, provided they
exhibit a vertical char of not more than 1.5 m when tested in conformance with the Vertical Flame Test – Cables in Cable
Trays (FT4 rating) in CSA C22.2 No. 0.3, “Test Methods for Electrical Wires and Cables.”
(4) Cables or wires within plenums that are used for the transmission of signals in fire alarm systems need not comply
with the requirements of Sentence (2).
3.1.4.4.Non-metallic Raceways permalink →
(1) Totally enclosed non-metallic raceways used in a plenum in a building permitted to be of combustible construction
shall meet the requirements of Clause 3.1.5.23.(1)(a).
3.1.4.5.Fire-Retardant-Treated Wood permalink →
(1) If fire-retardant-treated wood is specified in this Part, the wood shall
(a) be pressure impregnated with fire-retardant chemicals in conformance with CAN/CSA-O80 Series, “Wood
preservation,” and
(b) have a flame-spread rating not more than 25.
3.1.4.6.Heavy Timber Construction Alternative permalink →
(1) If combustible construction is permitted and is not required to have a fire-resistance rating more than 45 min, heavy
timber construction is permitted to be used.
(2) If heavy timber construction is permitted, it shall conform to Article 3.1.4.7.
3.1.4.7.Heavy Timber Construction permalink →
(1) Wood elements in heavy timber construction shall be arranged in heavy solid masses and with essentially smooth
flat surfaces to avoid thin sections and sharp projections.
(2) Except as permitted by Sentences (3) to (6) and (12), the minimum dimensions of wood elements in heavy timber
construction shall conform to Table 3.1.4.7.
(3) Where splice plates are used at splices of roof arches supported on the tops of walls or abutments, roof trusses, roof
beams and roof girders in heavy timber construction, they shall be not less than 64 mm thick.
(4) Floors in heavy timber construction shall be of glued-laminated or solid sawn plank not less than
(a) 64 mm thick, splined or tongued and grooved, or
(b) 38 mm wide and 89 mm deep set on edge and well-spiked together.
Table 3.1.4.7.
Heavy Timber Dimensions
Forming Part of Sentence 3.1.4.7.(2)
Solid Sawn Glued-Laminated
Round
Supported Assembly Structural Element (width × depth), (width × depth),
(diam), mm
mm × mm mm × mm
Columns 140 × 191 130 × 190 180
Arches supported on the tops of walls
89 × 140 80 × 152 ---
or abutments
Roofs only
Beams, girders and trusses 89 × 140 80 × 152 ---
Arches supported at or near the floor
140 × 140 130 × 152 ---
line
Columns 191 × 191 175 × 190 200
Floors, floors plus roofs 140 × 241 or 130 × 228 or
Beams, girders, trusses and arches ---
191 × 191 175 × 190
(5) Floors in heavy timber construction shall be laid
(a) so that no continuous line of end joints will occur except at points of support, and covered with
(i) tongued and grooved flooring not less than 19 mm thick laid crosswise or diagonally, or
(ii) tongued and grooved phenolic-bonded plywood, strandboard or waferboard not less than 12.5 mm thick, and
(b) not closer than 15 mm to the walls to provide for expansion, with the gap covered at the top or bottom.
(6) Roofs in heavy timber construction shall be of tongued and grooved phenolic-bonded plywood, strandboard or
waferboard not less than 28 mm thick, or glued-laminated or solid sawn plank that is
(a) not less than 38 mm thick, splined or tongued and grooved, or
(b) not less than 38 mm wide and 64 mm deep set on edge and laid so that no continuous line of end joints will occur
except at the points of support.
(7) Wood columns in heavy timber construction shall be continuous or superimposed throughout all storeys.
(8) Superimposed wood columns in heavy timber construction shall be connected by
(a) reinforced concrete or metal caps with brackets,
(b) steel or iron caps with pintles and base plates, or
(c) timber splice plates fastened to the columns by metal connectors housed within the contact faces.
(9) Where beams and girders in heavy timber construction enter masonry, wall plates, boxes of the self-releasing type or
hangers shall be used.
(10) Wood girders and beams in heavy timber construction shall be closely fitted to columns, and adjoining ends shall be
connected by ties or caps to transfer horizontal loads across the joints.
(11) In heavy timber construction, intermediate wood beams used to support a floor shall be supported on top of the
girders or on metal hangers into which the ends of the beams are closely fitted.
(12) Roof arches supported on the tops of walls or abutments, roof trusses, roof beams and roof girders in heavy timber
construction are permitted to be not less than 64 mm wide provided
(a) where two or more spaced members are used, the intervening spaces are
(i) blocked solidly throughout, or
(ii) tightly closed by a continuous wood cover plate not less than 38 mm thick secured to the underside of the
members, or
(b) the underneath of the roof deck or sheathing is sprinklered.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.4.8.Cladding permalink →
(1) Except as provided in Sentence (2), not less than 90% of the exterior cladding on each exterior wall of buildings
conforming to Article 3.2.2.51. or 3.2.2.60. shall consist of
(a) noncombustible cladding, or
(b) except as provided in Sentence (4), a wall assembly that satisfies the criteria of Clause 3.1.5.5.(1)(b).
(See Note A-3.1.4.8.(1)) (See also Notes A-3.1.5.5.(1)(b)(i) and A-3.1.5.5.(1)(b)(ii))
(2) Where a building is considered to face 1 street in accordance with Clause 3.2.2.10.(3)(b), the exterior cladding on
each exterior wall of buildings conforming to Article 3.2.2.51. or 3.2.2.60. shall consist of
(a) noncombustible cladding, or
(b) except as provided in Sentence (4), a wall assembly that satisfies the criteria of Clause 3.1.5.5.(1)(b).
(3) A wall assembly conforming to Clause (1)(b) or (2)(b) that includes combustible cladding made of fire-retardant-
treated wood shall be tested for fire exposure after the cladding has been subjected to the accelerated weathering test
specified in ASTM D2898, “Standard Practice for Accelerated Weathering of Fire-Retardant-Treated Wood for Fire
Testing.”
(4) An exterior wall assembly constructed in conformance with Section 6 of MMAH Supplementary Standard SB-2,
“Fire Performance Ratings” is deemed to satisfy the criteria of Clause (1)(b) and (2)(b).
3.1.5.Noncombustible Construction
3.1.5.1.Noncombustible Materials (See Note A-3.1.4.1.(1)) permalink →
(1) Except as permitted by Sentences (2) to (4) and Articles 3.1.5.2. to 3.1.5.29., 3.1.13.4. and 3.2.2.16., a building or
part of a building required to be of noncombustible construction, shall be constructed with noncombustible materials.
(See also Subsection 3.1.13. for the requirements regarding the flame-spread rating of interior finishes.)
(2) Notwithstanding the definition of noncombustible materials stated in Article 1.4.1.2. of Division A, a material is
permitted to be used in noncombustible construction provided that, when tested in accordance with ULC S135, “Standard
Test Method for the Determination of Combustibility Parameters of Building Materials Using an Oxygen Consumption
Calorimeter (Cone Calorimeter)”, at a heat flux of 50 kW/m 2,
(a) its average total heat release is not more than 3 MJ/m2,
(b) its average total smoke extinction area is not more than 1.0 m 2, and
(c) the test duration is extended beyond the time stipulated in the referenced standard until it is clear that there is no
further release of heat or smoke.
(3) If a material referred to in Sentence (2) consists of a number of discrete layers and testing reveals that the surface
layer or layers protect the underlying layers such that complete combustion of the underlying layers does not occur, the
test shall be repeated by removing the outer layers sequentially until all layers have been exposed during testing, or until
complete combustion has occurred.
(4) The acceptance criteria for a material tested in accordance with Sentence (3) shall be based on the cumulative
emissions from all layers, which must not exceed the criteria stated in Clauses (2)(a) and (b).
3.1.5.2.Minor Combustible Components permalink →
(1) The following minor combustible components are permitted in a building required to be of noncombustible
construction:
(a) paint, (See also Clause 3.1.13.1.(2)(b))
(b) self-adhesive tapes, mastics and caulking materials including foamed plastic air sealants, applied to provide a seal
between the major components of exterior wall construction, (See also Article 3.6.4.3. for limits on the use of
combustible materials in plenum spaces),
(c) firestops and fire blocks conforming to Sentence 3.1.9.1.(1) Article 3.1.11.7.,
(d) tubing for pneumatic controls provided it has an outside diameter not more than 10 mm,
(e) adhesives, vapour barriers and sheathing papers,
(f) electrical outlet and junction boxes,
(g) wood blocking intended for the attachment of window elements within exterior wall assemblies,
(h) wood blocking within wall assemblies intended for the attachment of handrails, fixtures, and similar items mounted
on the surface of the wall, and
(i) similar minor components.
3.1.5.3.Combustible Roofing Materials permalink →
(1) Combustible roof covering that has an A, B or C classification determined in conformance with Subsection 3.1.15. is
permitted on a building required to be of noncombustible construction.
(2) Combustible roof sheathing and roof sheathing supports installed above a concrete deck are permitted on a building
required to be of noncombustible construction provided
(a) the concrete deck is not less than 50 mm thick,
(b) the height of the roof space above the deck is not more than 1 m,
(c) the roof space is divided into compartments by fire blocks in conformance with Article 3.1.11.5.,
(d) openings through the concrete deck, other than for noncombustible roof drains and plumbing piping, are protected
by masonry or concrete shafts
(i) constructed as fire separations having a fire-resistance rating not less than 1 h, and
(ii) extending from the concrete deck to not less than 150 mm above the adjacent roof sheathing,
(e) the perimeter of the roof is protected by a noncombustible parapet extending from the concrete deck to not less than
150 mm above the adjacent sheathing, and
(f) except as permitted by Clause (d), the roof space does not contain any building services.
(3) Combustible cant strips, roof curbs, nailing strips and similar components used in the installation of roofing are
permitted on a building required to be of noncombustible construction.
(4) Wood nailer facings to parapets that are not more than 610 mm high are permitted on a building required to be of
noncombustible construction, provided the facings and any roof membranes covering the facings are protected by sheet
metal.
3.1.5.4.Combustible Windows, Glazing and Skylights permalink →
(1) Combustible skylight assemblies are permitted in a building required to be of noncombustible construction if the
assemblies have a flame-spread rating not more than
(a) 150 provided the assemblies
(i) have an individual area not more than 9 m2,
(ii) have an aggregate horizontal projected area of the openings through the ceiling not more than 25% of the area
of the ceiling of the room or space in which they are located, and
(iii) are spaced not less than 2.5 m from adjacent assemblies and 1 200 mm from required fire separations, or
(b) 75 provided the assemblies
(i) have an individual area not more than 27 m2,
(ii) have an aggregate horizontal projected area of the openings through the ceiling not more than 33% of the area
of the ceiling of the room or space in which they are located, and
(iii) are spaced not less than 1.2 m from adjacent assemblies and from required fire separations.
(See Note A-3.1.5.4.(1))
(2) Combustible vertical glazing installed no higher than the second storey is permitted in a building required to be of
noncombustible construction.
(3) Except as permitted by Sentence (4), the combustible vertical glazing permitted by Sentence (2) shall have a flame-
spread rating not more than 75.
(4) The flame-spread rating of combustible glazing is permitted to be not more than 150 if the aggregate area of glazing
is not more than 25% of the wall area of the storey in which it is located, and
(a) the glazing is installed in a building not more than 1 storey in building height,
(b) the glazing in the first storey is separated from the glazing in the second storey in accordance with the requirements
of Article 3.2.3.17. for opening protection, or
(c) the building is sprinklered throughout.
(5) Combustible window sashes and frames are permitted in a building required to be of noncombustible construction,
provided they are vertically non-contiguous between storeys.
3.1.5.5.Combustible Cladding on Exterior Walls permalink →
(1) Except as provided in Sentences (2) and (3), combustible cladding is permitted to be used on an exterior wall
assembly in a building required to be of noncombustible construction, provided
(a) the building is
(i) not more than 3 storeys in building height, or
(ii) sprinklered throughout, and
(b) except as provided in Sentence (4), when tested in accordance with CAN/ULC-S134, “Standard Method of Fire Test
of Exterior Wall Assemblies,” the wall assembly satisfies the following criteria for testing and conditions of
acceptance: (See Note A-3.1.5.5.(1)(b))
(i) flaming on or in the wall assembly does not spread more than 5 m above the opening, and (See Note A-
3.1.5.5.(1)(b)(i))
(ii) the heat flux during the flame exposure on the wall assembly is not more than 35 kW/m measured at 3.5 m
above the opening. (See Note A-3.1.5.5.(1)(b)(ii))
(2) Except as permitted by Articles 3.2.3.10. and 3.2.3.11., where the limiting distance in Tables 3.2.3.1.-B to 3.2.3.1.-E
permits an area of unprotected openings of not more than 10% of the exposing building face, the construction
requirements of Table 3.2.3.7. shall be met.
(3) A wall assembly permitted by Sentence (1) that includes combustible cladding of fire-retardant-treated wood shall
be tested for fire exposure after the cladding has been subjected to an accelerated weathering test as specified in ASTM
D2898, “Standard Practice for Accelerated Weathering of Fire-Retardant-Treated Wood for Fire Testing.”
(4) Exterior wall assemblies constructed in accordance with Section 6 of MMAH Supplementary Standard SB-2, “Fire
Performance Ratings” are deemed to comply with Clause (1)(b).
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.5.6.Combustible Components in Exterior Walls permalink →
(1) Combustible components, other than those permitted by Article 3.1.5.5. and Sentence 3.1.5.7.(2), are permitted to be
used in an exterior wall assembly of a building required to be of noncombustible construction, provided
(a) the building is
(i) not more than 3 storeys in building height, or
(ii) sprinklered throughout, and
(b) the wall assembly
(i) except as provided in Sentence (2), satisfies the criteria of Clause 3.1.5.5.(1)(b), or
(ii) is protected by masonry or concrete cladding not less than 25 mm thick.
(See Note A-3.1.5.5.(1)(b))
(2) Exterior wall assemblies constructed in accordance with Section 6 of MMAH Supplementary Standard SB-2, “Fire
Performance Ratings” are deemed to comply with Subclause (1)(b)(i).
3.1.5.7.Factory-Assembled Panels permalink →
(1) Except as provided in Sentence (2), factory-assembled wall and ceiling panels containing foamed plastic insulation
with a flame-spread rating not more than 500 are permitted to be used in a building required to be of noncombustible
construction, provided
(a) the building
(i) is sprinklered,
(ii) is not more than 18 m high, measured from grade to the underside of the roof, and
(iii) does not contain a Group A, Group B or Group C major occupancy, and
(b) the panels
(i) do not contain an air space,
(ii) when tested in accordance with CAN/ULC-S138, “Standard Method of Test for Fire Growth of Insulated
Building Panels in a Full-Scale Room Configuration,” meet the criteria defined therein, and
(iii) when a sample panel with an assembled joint typical of field installation is subjected to the applicable test
described in Subsection 3.1.12., have a flame-spread rating not more than that permitted for the room or
space that they bound.
(2) Factory-assembled exterior wall panels containing thermosetting foamed plastic insulation are permitted to be used
in a building required to be of noncombustible construction, provided
(a) the building
(i) is not more than 18 m high, measured from grade to the underside of the roof, and
(ii) does not contain a Group B or Group C major occupancy, and
(b) the wall panels
(i) do not contain an air space,
(ii) are protected on both sides by sheet steel not less than 0.38 mm thick,
(iii) remain in place for not less than 10 min when tested in accordance with CAN/ULC-S101, “Standard Method
of Fire Endurance Tests of Building Construction and Materials,” where the exposed surface includes typical
vertical and horizontal joints, and
(iv) when a sample panel with an assembled joint typical of field installation is subjected to the applicable test
described in Subsection 3.1.12., have a flame-spread rating not more than that permitted for the room or
space that they bound.
(3) A walk-in cooler or freezer consisting of factory-assembled wall, floor or ceiling panels containing foamed plastic
insulation with a flame-spread rating not more than 500 is permitted to be used in a building required to be of
noncombustible construction, provided
(a) the building is sprinklered, and
(b) the panels
(i) are protected on both sides by sheet metal not less than 0.38 mm thick with a melting point not less than
650°C,
(ii) do not contain an air space,
(iii) when tested in accordance with CAN/ULC-S138, “Standard Method of Test for Fire Growth of Insulated
Building Panels in a Full-Scale Room Configuration,” meet the criteria defined therein, and
(iv) when a sample panel with an assembled joint typical of field installation is subjected to the applicable test
described in Subsection 3.1.12., have a flame-spread rating not more than that permitted for the space in
which they are located or the space that they bound, as applicable.
(See Note A-3.1.4.2.(2) and 3.1.5.7.(3))
3.1.5.8.Nailing Elements permalink →
(1) Wood nailing elements attached directly to or set into a continuous noncombustible backing for the attachment of
interior finishes are permitted in a building required to be of noncombustible construction provided the concealed space
created by the wood elements is not more than 50 mm thick.
3.1.5.9.Combustible Millwork permalink →
(1) Combustible millwork, including interior trim, doors and door frames, show windows together with their frames,
aprons and backing, handrails, shelves, cabinets and counters, is permitted in a building required to be of noncombustible
construction.
3.1.5.10.Combustible Flooring Elements permalink →
(1) Combustible stage flooring supported on noncombustible structural members is permitted in a building required to
be of noncombustible construction.
(2) Wood members more than 50 mm but not more than 300 mm high applied directly to or set into a noncombustible
floor slab are permitted for the construction of a raised platform in a building required to be of noncombustible
construction provided the concealed spaces created are divided into compartments by fire blocks in conformance with
Sentence 3.1.11.3.(2).
(3) The floor system for the raised platform referred to in Sentence (2) is permitted to include combustible subfloor and
combustible finished flooring.
(4) Combustible finished flooring is permitted in a building required to be of noncombustible construction.
3.1.5.11.Combustible Stairs in Dwelling Units permalink →
(1) Combustible stairs are permitted in a dwelling unit in a building required to be of noncombustible construction.
3.1.5.12.Combustible Interior Finishes permalink →
(1) Except permitted in Sentences (2) and (3), combustible interior wall and ceiling finishes referred to in Clause
3.1.13.1.(2)(b) that are not more than 1 mm thick are permitted in a building required to be of noncombustible
construction.
(2) Combustible interior wall finishes, other than foamed plastics, that are not more than 25 mm thick are permitted in a
building required to be of noncombustible construction, provided they have a flame-spread rating not more than 150 on
any exposed surface or any surface that would be exposed by cutting through the material in any direction.
(3) Except as provided in Sentence (4), combustible interior ceiling finishes, other than foamed plastics, that are not
more than 25 mm thick are permitted in a building required to be of noncombustible construction, provided they have a
flame-spread rating not more than 25 on any exposed surface or on any surface that would be exposed by cutting through
the material in any direction, except that not more than 10% of the ceiling area within each fire compartment is permitted
to have a flame-spread rating not more than 150.
(4) Combustible interior ceiling finishes made of fire-retardant-treated wood are permitted in a building required to be
of noncombustible construction, provided they are not more than 25 mm thick or are exposed fire-retardant-treated wood
battens.
3.1.5.13.Gypsum Board permalink →
(1) Gypsum board with a tightly adhering paper covering not more than 1 mm thick is permitted in a building required
to be of noncombustible construction provided the flame-spread rating of the surface is not more than 25.
3.1.5.14.Combustible Insulation (See Notes A-3.1.4.2. and A-3.1.4.2.(1)) permalink →
(1) Foamed plastic insulation shall conform to Article 3.1.5.15.
(2) Combustible insulation with a flame-spread rating not more than 25 on any exposed surface, or any surface that
would be exposed by cutting through the material in any direction, is permitted in a building required to be of
noncombustible construction.
(3) Combustible insulation is permitted to be installed above roof decks, outside of foundation walls below ground level
and beneath concrete slabs-on-ground of buildings required to be of noncombustible construction.
(4) Except as provided in Sentences (5) and (6), combustible insulation with a flame-spread rating more than 25 but not
more than 500 on any exposed surface, or any surface that would be exposed by cutting through the material in any
direction, is permitted in a building required to be of noncombustible construction, provided the insulation is protected
from adjacent space in the building, other than adjacent concealed spaces within wall assemblies, by a thermal barrier
consisting of
(a) not less than 12.7 mm thick gypsum board mechanically fastened to a supporting assembly independent of the
insulation,
(b) lath and plaster, mechanically fastened to a supporting assembly independent of the insulation,
(c) masonry, or
(d) concrete.
(5) Combustible insulation with a flame-spread rating more than 25 but not more than 500 on any exposed surface, or
any surface that would be exposed by cutting through the material in any direction, is permitted in the exterior walls of a
building required to be of noncombustible construction that is not sprinklered and is more than 18 m high, measured from
grade to the underside of the roof, provided the insulation is protected from adjacent space in the building, other than
adjacent concealed spaces within wall assemblies, by a thermal barrier consisting of
(a) gypsum board not less than 12.7 mm thick, mechanically fastened to a supporting assembly independent of the
insulation and with all joints either backed or taped and filled,
(b) lath and plaster, mechanically fastened to a supporting assembly independent of the insulation,
(c) masonry or concrete not less than 25 mm thick, or
(d) any thermal barrier that, when tested in conformance with CAN/ULC-S101, “Standard Method of Fire Endurance
Tests of Building Construction and Materials,” will not develop an average temperature rise more than 140°C or a
maximum temperature rise more than 180°C at any point on its unexposed face within 10 min. (See Note A-
3.1.5.14.(5)(d)) (See also Article 3.2.3.7.)
(6) Combustible insulation with a flame-spread rating more than 25 but not more than 500 on any exposed surface, or
any surface that would be exposed by cutting through the material in any direction, is permitted in the interior walls,
within ceilings and within roof assemblies of a building required to be of noncombustible construction that is not
sprinklered and is more than 18 m high, measured from grade to the underside of the roof, provided the insulation is
protected from adjacent space in the building, other than adjacent concealed spaces within wall assemblies, by a thermal
barrier consisting of
(a) Type X gypsum board not less than 15.9 mm thick, mechanically fastened to a supporting assembly independent of
the insulation and with all joints either backed or taped and filled, conforming to
(i) ASTM C1177 / C1177M, “Standard Specification for Glass Mat Gypsum Substrate for Use as Sheathing,”
(ii) ASTM C1178 / C1178M, “Standard Specification for Coated Glass Mat Water-Resistant Gypsum Backing
Panel,”
(iii) ASTM C1396 / C1396M, “Standard Specification for Gypsum Board,”
(iv) ASTM C1658 / C1658M, “Standard Specification for Glass Mat Gypsum Panels,” or
(v) CAN/CSA-A82.27-M, “Gypsum Board,”
(b) of non-loadbearing masonry or concrete not less than 50 mm thick,
(c) loadbearing masonry or concrete not less than 75 mm thick, or
(d) any thermal barrier that, when tested in conformance with CAN/ULC-S101, “Standard Method of Fire Endurance
Tests of Building Construction and Materials,”
(i) does not develop an average temperature rise more than 140°C or a maximum temperature rise more than
180°C at any point on its unexposed face within 20 min, and
(ii) remains in place for not less than 40 min.
3.1.5.15.Foamed Plastic Insulation (See Notes A-3.1.4.2. and A-3.1.4.2.(1)) permalink →
(1) Foamed plastic insulation is permitted to be installed above roof decks, outside of foundation walls below ground
level and beneath concrete slabs-on-ground of a building required to be of noncombustible construction.
(2) Except as provided in Sentences (3), (4) and 3.1.5.7.(1), foamed plastic insulation with a flame-spread rating not
more than 500 on any exposed surface, or any surface that would be exposed by cutting through the material in any
direction, is permitted in a building required to be of noncombustible construction, provided the insulation is protected
from adjacent space in the building, other than adjacent concealed spaces within wall assemblies, by a thermal barrier
consisting of
(a) not less than 12.7 mm thick gypsum board mechanically fastened to a supporting assembly independent of the
insulation,
(b) lath and plaster, mechanically fastened to a supporting assembly independent of the insulation,
(c) masonry,
(d) concrete, or
(e) any thermal barrier that meets the requirements of classification B when tested in conformance with CAN/ULC-
S124, “Standard Method of Test for the Evaluation of Protective Coverings for Foamed Plastic”.
(3) Foamed plastic insulation with a flame-spread rating more than 25 but not more than 500 on any exposed surface, or
any surface that would be exposed by cutting through the material in any direction, is permitted in the exterior walls of a
building required to be of noncombustible construction that is not sprinklered and is more than 18 m high, measured from
grade to the underside of the roof, provided the insulation is protected from adjacent space in the building, other than
adjacent concealed spaces within wall assemblies, by a thermal barrier consisting of
(a) gypsum board not less than 12.7 mm thick, mechanically fastened to a supporting assembly independent of the
insulation and with all joints either backed or taped and filled,
(b) lath and plaster, mechanically fastened to a supporting assembly independent of the insulation,
(c) masonry or concrete not less than 25 mm thick, or
(d) any thermal barrier that, when tested in conformance with CAN/ULC-S101, “Standard Method of Fire Endurance
Tests of Building Construction and Materials,” does not develop an average temperature rise more than 140°C or a
maximum temperature rise more than 180°C at any point on its unexposed face within 10 min. (See Note A-
3.1.5.14.(5)(d)) (See also Article 3.2.3.7.)
(4) Foamed plastic insulation with a flame-spread rating more than 25 but not more than 500 on any exposed surface, or
any surface that would be exposed by cutting through the material in any direction, is permitted in the interior walls,
within ceilings and within roof assemblies of a building required to be of noncombustible construction that is not
sprinklered and is more than 18 m high, measured from grade to the underside of the roof, provided the insulation is
protected from adjacent space in the building, other than adjacent concealed spaces within wall assemblies, by a thermal
barrier consisting of
(a) Type X gypsum board not less than 15.9 mm thick, mechanically fastened to a supporting assembly independent of
the insulation and with all joints either backed or taped and filled, conforming to
(i) ASTM C1177 / C1177M, “Standard Specification for Glass Mat Gypsum Substrate for Use as Sheathing,”
(ii) ASTM C1178 / C1178M, “Standard Specification for Coated Glass Mat Water-Resistant Gypsum Backing
Panel,”
(iii) ASTM C1396 / C1396M, “Standard Specification for Gypsum Board,” or
(iv) CAN/CSA-A82.27-M, “Gypsum Board,”
(b) non-loadbearing masonry or concrete not less than 50 mm thick,
(c) loadbearing masonry or concrete not less than 75 mm thick, or
(d) any thermal barrier that, when tested in conformance with CAN/ULC-S101, “Standard Method of Fire Endurance
Tests of Building Construction and Materials,”
(i) does not develop an average temperature rise more than 140°C or a maximum temperature rise more than
180°C at any point on its unexposed face within 20 min, and
(ii) remains in place for not less than 40 min.
3.1.5.16.Combustible Elements in Partitions permalink →
(1) Except as permitted by Sentence (2), solid lumber partitions not less than 38 mm thick and wood framing in
partitions located in a fire compartment not more than 600 m2 in area are permitted to be used in a building required to be
of noncombustible construction in a floor area that is not sprinklered provided the partitions
(a) are not required fire separations, and
(b) are not located in a care, care and treatment or detention occupancy or in a retirement home.
(2) Partitions installed in a building of noncombustible construction are permitted to contain wood framing provided
(a) the building is not more than 3 storeys in building height,
(b) the partitions are not located in a care, care and treatment or detention occupancy or in a retirement home, and
(c) the partitions are not installed as enclosures for exits or vertical service spaces.
(3) Solid lumber partitions not less than 38 mm thick and partitions that contain wood framing are permitted to be used
in a building required to be of noncombustible construction provided
(a) the floor area containing the partitions is sprinklered throughout, and
(b) the partitions are not
(i) located in a care, care and treatment or detention occupancy or in a retirement home,
(ii) installed as enclosures for exits or vertical service spaces, or
(iii) used to satisfy the requirements of Clause 3.2.8.1.(1)(a).
3.1.5.17.Storage Lockers in Residential Buildings permalink →
(1) Except in a retirement home, storage lockers in storage rooms are permitted to be constructed of wood in a building
of residential occupancy required to be of noncombustible construction.
3.1.5.18.Combustible Ducts permalink →
(1) Except as required by Sentence 3.6.4.3.(1), combustible ducts, including plenums and duct connectors, are permitted
to be used in a building required to be of noncombustible construction provided these ducts and duct connectors are used
only in horizontal runs.
(2) Combustible duct linings, duct coverings, duct insulation, vibration isolation connectors, duct tape, pipe insulation
and pipe coverings are permitted to be used in a building required to be of noncombustible construction provided they
conform to the appropriate requirements of Subsection 3.6.5.
(3) In a building required to be of noncombustible construction, combustible ducts need not comply with the
requirements of Sentences 3.6.5.1.(1) and (2) provided the ducts are
(a) part of a duct system conveying only ventilation air, and
(b) contained entirely within a dwelling unit.
3.1.5.19.Combustible Piping Materials permalink →
(1) Except as permitted by Clause 3.1.5.2.(1)(d) and Article 3.1.5.25. and Sentences (2) and (3), combustible piping and
tubing and associated adhesives are permitted to be used in a building required to be of noncombustible construction
provided that, except when concealed in a wall or concrete floor slab, they
(a) have a flame-spread rating not more than 25, and
(b) if used in a building described in Subsection 3.2.6., have a smoke developed classification not more than 50.
(2) Combustible sprinkler piping is permitted to be used within a sprinklered floor area in a building required to be of
noncombustible construction. (See also Article 3.2.5.13.)
(3) Polypropylene pipes and fittings are permitted to be used for drain, waste and vent piping for the conveyance of
highly corrosive materials and for piping used to distribute distilled or dialyzed water in laboratory and hospital facilities
in a building required to be of noncombustible construction, provided
(a) the building is sprinklered throughout,
(b) the piping is not located in a vertical shaft, and
(c) piping that penetrates a fire separation is sealed at the penetration by a firestop that has an FT rating not less than
the fire-resistance rating of the fire separation when subjected to the fire test method in CAN/ULC-S115, “Standard
Method of Fire Tests of Firestop Systems,” with a pressure differential of 50 Pa between the exposed and unexposed
sides, with the higher pressure on the exposed side.
3.1.5.20.Combustible Plumbing Fixtures permalink →
(1) Combustible plumbing fixtures including wall and ceiling enclosures that form part of the plumbing fixture, are
permitted in a building required to be of noncombustible construction provided they are constructed of material having a
flame-spread rating and smoke developed classification not more than that permitted for the wall surface of the
room or space in which they are installed.
3.1.5.21.Wires and Cables permalink →
(1) Except as permitted by Sentence (2) and Articles 3.1.5.22. and 3.1.5.25., optical fibre cables and electrical wires and
cables with combustible insulation, jackets or sheathes are permitted in a building required to be of noncombustible
construction, provided
(a) the wires and cables exhibit a vertical char of not more than 1.5 m when tested in conformance with the Vertical
Flame Test – Cables in Cable Trays (FT4 rating) in CSA C22.2 No. 0.3, “Test methods for electrical wires and
cables,”
(b) the wires and cables are located in
(i) totally enclosed noncombustible raceways, (See Note A-3.1.4.3.(1)(b)(i))
(ii) masonry walls,
(iii) concrete slabs,
(iv) a service room separated from the remainder of the building by a fire separation having a fire-resistance
rating not less than 1 h, or
(v) totally enclosed non-metallic raceways conforming to Clause 3.1.5.23.(1)(b), or
(c) the wires and cables are communication cables used at the service entry to a building and are not more than 3 m
long.
(See Note A-3.1.5.21.(1))
(2) Except as permitted in Sentences (3) and (4), 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 are not located in totally
enclosed noncombustible raceways are permitted to be installed in a plenum in a building required to be of
noncombustible construction, provided the wires and cables exhibit a horizontal flame distance of not more than 1.5 m, an
average optical smoke density of not more than 0.15, and a peak optical smoke density of not more than 0.5 when tested
in conformance with CAN/ULC-S102.4, “Standard Method of Test for Fire and Smoke Characteristics of Electrical
Wiring, Cables and Non-Metallic Raceways,” (FT6 rating).
(3) Except as permitted in Sentence (4), where totally enclosed noncombustible raceways are used in a plenum, exposed
components of wiring systems with combustible insulation, jackets or sheathes, including optical fibre cables and
electrical wires and cables that are used for the transmission of voice, sound or data, that are installed in the plenum or
that extend not more than 9 m from the plenum including drop down to the floor level, are permitted provided they exhibit
a vertical char of not more than 1.5 m when tested in conformance with the Vertical Flame Test – Cables in Cable Trays
(FT4 rating) in CSA C22.2 No. 0.3, “Test methods for electrical wires and cables.”
(4) Cables or wires within plenums that are used for the transmission of signals in fire alarm systems need not comply
with the requirements of Sentences (2) and (3).
3.1.5.22.Combustible Travelling Cables for Elevators permalink →
(1) Combustible travelling cables are permitted on elevating devices in a building required to be of noncombustible
construction.
3.1.5.23.Non-metallic Raceways permalink →
(1) Except as required in Sentence (2), subject to the limits on the size of elements that penetrate fire separations when
complying with Article 3.1.9.2., within a fire compartment of a building required to be of noncombustible construction,
totally enclosed non-metallic raceways not more than 175 mm in outside diameter, or of an equivalent rectangular area,
are permitted to be used to enclose optical fibre cables and electrical wires and cables, provided
(a) where the wires and cables in the raceways meet or exceed the requirements of Clause 3.1.5.21.(1)(a), the non-
metallic raceways meet the requirements for at least an FT4 rating in,
(i) CAN/CSA-C22.2 No. 262, “Optical Fiber Cable and Communication Cable Raceway Systems,” or
(ii) CAN/ULC-S143, “Standard Method of Fire Tests for Non-Metallic Electrical and Optical Fibre Cable
Raceway Systems,” and
(b) where the wires and cables in the raceways do not meet or exceed the requirements of Clause 3.1.5.21.(1)(a), the
non-metallic raceways exhibit a vertical char of not more than 1.5 m when tested in conformance with the Vertical
Flame Test (FT4) – Conduit or Tubing on Cable Tray in Clause 6.16 of CSA C22.2 No. 211.0, “General
Requirements and Methods of Testing for Nonmetallic Conduit.”
(2) Totally enclosed non-metallic raceways used in a plenum in a building required to be of noncombustible
construction shall exhibit a horizontal flame distance of not more than 1.5 m, an average optical smoke density of not
more than 0.15, and a peak optical smoke density of not more than 0.5 when tested in conformance with CAN/ULC-
S102.4, “Standard Method of Test for Fire and Smoke Characteristics of Electrical Wiring, Cables and Non-Metallic
Raceways,” (FT6 rating).
3.1.5.24.Wood Decorative Cladding permalink →
(1) On buildings required to be of noncombustible construction, decorative wood cladding is permitted to be used on the
exterior fascias and soffits of marquees or canopies on the building face of a storey having direct access to a street or
access route, provided the wood cladding is fire-retardant-treated wood that has been conditioned in conformance with
ASTM D2898, “Standard Practice for Accelerated Weathering of Fire-Retardant-Treated Wood for Fire Testing,” before
being tested in accordance with CAN/ULC-S102, “Standard Method of Test for Surface Burning Characteristics of
Building Materials and Assemblies.”
3.1.5.25.Wires in Computer Room Floors permalink →
(1) Optical fibre cables and electrical wires and cables with combustible insulation, jackets or sheathes, located in the
space below a raised floor in a computer room, are permitted in a building required to be of noncombustible construction
provided they do not convey flame or continue to burn for more than 1 min when tested in conformance with the Vertical
Flame Test in Clause 4.11.1. of CSA C22.2 No. 0.3, “Test methods for electrical wires and cables,” (FT1 Rating).
(2) The requirement in Sentence (1) is considered to be met where the wires and cables
(a) exhibit a vertical char of not more than 1.5 m when tested in conformance with the Vertical Flame Test – Cables in
Cabletrough in Clause 4.11.4. of CSA C22.2 No. 0.3, “Test methods for electrical wires and cables,” (FT4 Rating),
or
(b) exhibit a flame-spread of not more than 1.5 m, a smoke density of not more than 0.5 at peak optical density and a
smoke density not more than 0.15 at average optical density when tested in conformance with the Flame and Smoke
Test in the Appendix to CSA C22.2 No. 0.3, “Test methods for electrical wires and cables,” (FT6 Rating).
3.1.5.26.Combustible Components in Public Pools and Public Spas permalink →
(1) Combustible fittings and components in a public pool or public spa, including main drains, piping, skimmers, return
inlets, steps, ladder rungs and liners, are permitted in a building required to be of noncombustible construction.
3.1.5.27.Combustible Mezzanines permalink →
(1) In a building required to be of noncombustible construction, a mezzanine located within a live/work unit is permitted
to be of combustible construction, provided the area of the mezzanine is not more than 25% of the floor area of the
live/work unit or 20 m2, whichever is less, and has no obstructions more than 1 070 mm above the floor.
3.1.5.28.Combustible Solar Collector Systems permalink →
(1) A combustible solar collector system is permitted to be installed above the roof of a building required to be of
noncombustible construction.
3.1.5.29.Marquees Having Combustible Elements permalink →
(1) Except as permitted in Sentence (2), exterior marquees, not greater than 7.5 m from ground level to the top of the
marquee, having combustible elements, other than fabrics or films conforming to Sentence 3.1.16.1.(1), are permitted on a
building required to be of noncombustible construction, provided every opening in the exposed wall of the building above
the marquee is protected with wired glass in accordance with MMAH Supplementary Standard SB-2, “Fire Performance
Ratings” where these openings are within,
(a) 4.5 m horizontally of the marquee, and
(b) 9 m vertically above the marquee.
(2) The protection required by Sentence (1) is permitted to be waived if the building is sprinklered.
3.1.6.Encapsulated Mass Timber Construction (See Note A-3.1.6.)
3.1.6.1.Scope permalink →
(1) Encapsulated mass timber construction permitted in this Part shall conform to this Subsection.
3.1.6.2.Materials Permitted permalink →
(1) Except as otherwise provided in this Part and Sentence 6.4.3.1.(1), materials used in a building or part of a building
permitted to be of encapsulated mass timber construction shall conform to Subsection 3.1.5.
3.1.6.3.Structural Mass Timber Elements (See Note A-3.1.6.3.) permalink →
(1) Except as otherwise provided in this Subsection and Articles 3.2.2.16. and 3.2.3.19., a building or part of a building
permitted to be of encapsulated mass timber construction is permitted to include structural mass timber elements,
including beams, columns, arches and wall, floor and roof assemblies, provided they comply with Sentences (2) and (3).
(2) Structural mass timber elements referred to in Sentence (1) shall
(a) except as provided in Sentence (4), be arranged in heavy solid masses containing no concealed spaces,
(b) have essentially smooth flat surfaces with no thin sections or sharp projections, and
(c) except as provided in Sentence 3.1.6.17.(1), conform to the minimum dimensions stated in Table 3.1.6.3.
(3) Adhesives used in structural mass timber elements referred to in Sentence (1) that are constructed of cross-laminated
timber shall conform to the elevated temperature performance requirements in ANSI/APA PRG 320, “Standard for
Performance-Rated Cross-Laminated Timber.”
(4) Concealed spaces are permitted within structural mass timber elements referred to in Sentence (2) and need not
conform to Sentence 3.1.6.4.(1) provided the concealed spaces are,
(a) sprinklered and divided into compartments by fire blocks in conformance with Subsection 3.1.11.,
(b) completely filled with rock or slag fibre insulation conforming to CAN/ULC-S702.1 “Standard for Mineral Fibre
Thermal Insulation for Buildings, Part 1: Material Specification,” and having a density not less than 32 kg/m3,
(c) if horizontal, lined with not less than a single layer of 12.7 mm thick Type X gypsum board or noncombustible
material providing an encapsulation rating of not less than 25 min, or
(d) if vertical, lined with not less than a single layer of 12.7 mm thick Type X gypsum board or noncombustible material
providing an encapsulation rating of not less than 25 min and vertically divided into compartments by fire blocks in
conformance with Subsection 3.1.11.
Table 3.1.6.3.
Minimum Dimensions of Structural Mass Timber Elements in Encapsulated Mass Timber Construction
Forming Part of Sentences 3.1.6.3.(2), 3.1.6.8.(1) and 3.1.6.17.(1)
Structural Wood Elements Minimum Thickness, mm Minimum Width x Depth, mm x mm
Walls that are not fire separations or exterior walls
96 —
(1-sided fire exposure)
Walls that require a fire-resistance rating, but are
192 —
not fire separations (2-sided fire exposure)
Floors(1) and roofs (1-sided fire exposure) 96 —
Beams, columns and arches (2- or 3-sided fire
— 192 x 192
exposure)
Beams, columns and arches (4-sided fire exposure) — 224 x 224
Notes to Table 3.1.6.3.:
(1) The minimum dimensions for floor assemblies are also applicable to mezzanines and exterior balconies.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.6.4.Encapsulation of Mass Timber Elements (See Note A-3.1.6.3.) permalink →
r1 (1) Except as provided in Sentences (3) to (9), 3.1.6.3.(4), 3.1.6.16.(2) and 3.1.6.17.(2), and Articles 3.1.6.7. and
3.1.6.12., the exposed surfaces of structural mass timber elements conforming to Article 3.1.6.3. shall be protected from
adjacent spaces in the building, including adjacent concealed spaces within wall, floor and roof assemblies, by a material
or assembly of materials conforming to Sentence (2) that provides an encapsulation rating that
(a) is not less than 50 min in a building or part thereof constructed in conformance with Article 3.2.2.48. or 3.2.2.57., or
(b) conforms to the minimum values stated in Table 3.2.2.93. for the applicable major occupancy and building height.
(See Note A-3.1.6.4.(1))
(2) Except as provided in Sentence 3.1.6.11.(1), the material or assembly of materials referred to Sentence (1) shall
consist of
(a) gypsum board,
(b) gypsum concrete,
(c) noncombustible materials,
(d) materials that conform to Sentences 3.1.5.1.(2) to (4), or
(e) any combination of materials listed in Clauses (a) to (d).
r1 (3) Except as provided in Sentences (5) and (7), the exposed surfaces of mass timber beams, columns and arches within
a suite or fire compartment in a building or part thereof constructed in conformance with Article 3.2.2.48. or 3.2.2.57. or
permitted by Article 3.2.2.93. to have a 50 min encapsulation rating need not be protected in accordance with
Sentence (1), provided
(a) their aggregate exposed surface area does not exceed 35% of the total wall area of the perimeter of the suite or fire
compartment in which they are located, and
(b) the flame-spread rating on any exposed surface is not more than 150.
(See Note A-3.1.6.4.(3) to (8))
r1 (4) Except as provided in Sentences (5) to (7), the exposed surfaces of mass timber walls within a suite in a building or
part threreof constructed in conformance with Article 3.2.2.48. or 3.2.2.57. or permitted by Article 3.2.2.93. to have a 50
min encapsulation rating need not be protected in accordance with Sentence (1), provided
(a) all portions of the exposed surfaces,
(i) face the same direction, or
(ii) are separated by a horizonal distance of not less than 4.5 m, and
(b) the flame-spread rating on any exposed surface is not more than 150.
(See Notes A-3.1.6.4.(4) and A-3.1.6.4.(3) to (8))
r1 (5) Except as provided in Sentence (7), the aggregate exposed surface area of mass timber elements within a suite
permitted in Sentences (3) and (4) shall not exceed 35% of the total wall area of the perimeter of the suite. (See Note A-
3.1.6.4.(3) to (8))
r1 (6) Except as provided in Sentence (7), the exposed surfaces of mass timber ceilings within a suite or fire compartment,
other than an exit and public corridor, in a building or part thereof constructed in conformance with Article 3.2.2.48. or
3.2.2.57. or permitted by Article 3.2.2.93. to have a 50 min encapsulation rating need not be protected in accordance with
Sentence (1), provided the aggregate surface area does not exceed
(a) 10% of the total ceiling area of the suite or fire compartment, where the flame-spread rating on any exposed surface
is not more than 150, or
(b) 25% of the total ceiling area of the suite or fire compartment, where the flame-spread rating on any exposed surface
of a mass timber wall or ceiling is not more than 75.
(See Note A-3.1.6.4.(3) to (8))
r1 (7) The exposed surfaces of mass timber ceilings within a suite in a building or part thereof constructed in conformance
with Article 3.2.2.48. or 3.2.2.57. or permitted by Article 3.2.2.93. to have a 50 min encapsulation rating need not be
protected in accordance with Sentence (1) or (6), provided
(a) the aggregate surface area of any exposed mass timber beams, columns and arches does not exceed 20% of the total
wall area of the perimeter of the suite in which they are located,
(b) all surface of the mass timber walls are,
(i) protected in accordance with Sentence (1), or
(ii) mass timber walls that are not otherwise permitted to be exposed in accordance with Sentence (5) are
protected by a material or assembly of materials conforming to Sentence (2) that provides an encapsulation
rating of not less than 80 min, and
(c) the flame spread rating on any exposed mass timber wall or ceiling is not more than 75.
(See Note A-3.1.6.4.(3) to (8))
r1 (8) Structural mass timber elements in a building or part thereof permitted by Article 3.2.2.93. to have a 0 min
encapsulation rating need not be protected in accordance with Sentence (1), provided
(a) mass timber walls and ceilings within vertical service spaces, public corridors, and exits are protected on the interior
side with a material or assembly of materials conforming to Sentence (2) that provides an encapsulation rating of
not less than 25 min, and
(b) concealed spaces are protected in conformance with Sentence 3.1.6.3.(4).
(See Note A-3.1.6.4.(3) to (8))
(9) In a building or part thereof required by Clause 3.1.6.4.(1)(b) to have a minimum encapsulation rating of 70 min,
the upper side of a mass timber floor or roof assembly is permitted to be encapsulated by a material or assembly of
materials conforming to Sentence 3.1.6.4.(2) that provides an encapsulation rating of 50 min.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.6.5.Determination of Encapsulation Ratings permalink →
(1) Except as provided in Article 3.1.6.6., the rating of a material or assembly of materials that is required to have an
encapsulation rating shall be determined on the basis of the results of the tests conducted in conformance with CAN/ULC-
S146, “Standard Method of Test for the Evaluation of Encapsulation Materials and Assemblies of Materials for the Protection
of Structural Timber Elements.”
3.1.6.6.Encapsulation Materials (See Note A-3.1.6.6.) permalink →
(1) Gypsum-concrete topping and concrete not less than 38 mm thick are deemed to have an encapsulation rating of
50 min when installed on the upper side of a mass timber floor or roof assembly.
r1 (2) One layer of Type X gypsum board conforming to ASTM C1396/C1396M, “Standard Specification for Gypsum
Board,” or CAN/CSA-A82.27-M, “Gypsum Board,” not less than 12.7 mm thick, are deemed to have an encapsulation
rating of 25 min when installed on a mass timber element in accordance with Sentence (6).
r1 (3) Two layers of Type X gypsum board conforming to ASTM C1396/C1396M, “Standard Specification for Gypsum
Board,” or CAN/CSA-A82.27-M, “Gypsum Board,” each not less than 12.7 mm thick, are deemed to have an
encapsulation rating of 50 min when installed on a mass timber element in accordance with Sentence (6).
r1 (4) Two layers of Type X gypsum board conforming to ASTM C1396/C1396M, “Standard Specification for Gypsum
Board,” or CAN/CSA-A82.27-M, “Gypsum Board,” each not less than 15.9 mm thick, are deemed to have an
encapsulation rating of 70 min when installed on a mass timber element in accordance with Sentence (6).
r1 (5) Three layers of Type X gypsum board conforming to ASTM C1396/C1396M, “Standard Specification for Gypsum
Board,” or CAN/CSA-A82.27-M, “Gypsum Board,” each not less than 12.7 mm thick, are deemed to have an
encapsulation rating of 80 min when installed on a mass timber element in accordance with Sentence (6).
r1 (6) The gypsum board described in Sentences (2) to (5) shall be
(a) fastened with a minimum of two rows of screws in each layer
(i) directly to the mass timber element with screws of sufficient length to penetrate not less than 20 mm into the
mass timber element that are spaced not more than 400 mm o.c. and 20 mm to 38 mm from the boards’ edges,
or
(ii) to wood furring or resilient metal or steel furring channels not more than 25 mm thick spaced not more than
400 mm o.c. on the mass timber element,
(b) for multiple layer systems, installed with the joints in each layer staggered from those in the adjacent layer, and
(c) installed in conformance with ASTM C840, “Standard Specification for Application and Finishing of Gypsum
Board,” except that, for multiple layer systems, their joints need not be taped and finished.
(See Note A-3.1.6.6.(6))
3.1.6.7.Combustible Roofing Materials permalink →
(1) Wood roof sheathing and roof sheathing supports that do not conform to Articles 3.1.6.3. and 3.1.6.4. are permitted
in a building or part of a building permitted to be of encapsulated mass timber construction, provided they are installed
(a) above a concrete deck in accordance with Sentence 3.1.5.3.(2), or
(b) above a deck of encapsulated mass timber construction, where
(i) said deck is permitted to be encapsulated between the roof sheathing supports by a material or assembly of
materials conforming to Sentence 3.1.6.4.(2) that provides an encapsulation rating of not less than 50 min,
(ii) the height of the roof space is not more than 1 m,
(iii) the roof space is divided into compartments by fire blocks in conformance with Article 3.1.11.5.,
(iv) openings through the deck other than for noncombustible roof drains and plumbing piping are protected by
shafts constructed as fire separations having a fire-resistance rating not less than 1 h that extend from the
deck to not less than 150 mm above the adjacent sheathing, and
(v) except as permitted by Subclause (b)(iv), the roof space does not contain any building services.
(2) Combustible cant strips, roof curbs, nailing strips and similar components used in the installation of roofing are
permitted on a building or part of a building permitted to be of encapsulated mass timber construction.
(3) Wood nailer facings to parapets that are not more than 610 mm high are permitted on a building or part of a building
permitted to be of encapsulated mass timber construction, provided the facings and any roof membranes covering the
facings are protected by sheet metal.
3.1.6.8.Combustible Window Sashes and Frames permalink →
(1) Combustible window sashes and frames are permitted in a building or part of a building permitted to be of
encapsulated mass timber construction, provided
(a) each window in an exterior wall face is an individual unit separated from every other opening in the wall by
noncombustible wall construction or mass timber wall construction conforming to the dimensions stated in Table
3.1.6.3.,
(b) windows in exterior walls in contiguous storeys are separated by not less than 1 m of noncombustible wall
construction or mass timber wall construction conforming to the dimensions stated in Table 3.1.6.3., and
(c) the aggregate area of openings in an exterior wall face of a fire compartment is not more than 40% of the area of the
wall face.
r1 3.1.6.9. Exterior Cladding
(1) Except as provided in Sentences (2) to (5) and (8), cladding on an exterior wall assembly of a building or part
thereof permitted to be of encapsulated mass timber construction shall be
(a) noncombustible,
(b) a material or combination of materials that satisfy the criteria of Sentence 3.1.5.1.(2),
(c) except as provided in Sentence (6), a wall assembly that satisfies the criteria of Clause 3.1.5.5.(1)(b), or
(d) a combination of the cladding described in Clauses (a) to (c).
(See Note A-3.1.6.9.(1), (2), (4) and (5))
(2) Except as provided in Sentences (3) to (5) and (7), cladding on an exterior wall assembly of a building or part
thereof permitted to be of encapsulated mass timber construction that is not more than 12 storeys in building height is
permitted to consist of
(a) combustible cladding that
(i) is not contiguous over more than 4 storeys,
(ii) represents not more than 10% of the cladding on each exterior wall of each storey,
(iii) is not more than 1.2 m in width,
(iv) has a flame-spread rating not more than 75 on any exposed surface, or any surface that would by exposed by
cutting through the material in any direction,
(v) is separated from other portions of combustible cladding on adjacent storeys by a horizontal distance of not
less than 2.4 m, and
(vi) is separated from other portions of combustible cladding by a horizontal distance of not less than 1.2 m,
(b) combustible cladding that
(i) is not contiguous across adjacent storeys,
(ii) represents not more than 10% of the cladding on each exterior wall of each storey,
(iii) has a flame-spread rating not more than 75 on any exposed surface, or any surface that would be exposed by
cutting through the material in any direction, and
(iv) is separated from other portions of combustible cladding on adjacent storeys by a horizontal distance of not
less than 2.4 m,
(c) combustible cladding representing up to 100% of the cladding on exterior walls of the first storey, provided all
portions of the cladding can be directly accessed and are located not more than 15 m from a street or access route
conforming to Article 3.2.5.6., measured horizontally from the face of the building, or
(d) a combination of cladding described in Sentence (1) and the cladding described in Clauses (a) to (c).
(See Note A-3.1.6.9.(1), (2), (4) and (5))
(3) The permitted area of combustible cladding referred to in Clause (2)(a) or (b) shall not exceed 5% of the cladding on
each exterior wall of each storey where firefighting facilities cannot reach the building within 10 min of the alarm being
received.
(4) Except as provided in Sentences (5) and (7), cladding on an exterior wall assembly of a building or part thereof
permitted to be of encapsulated mass timber construction that is not more than 6 storeys in building height is permitted to
consist of
(a) combustible cladding that
(i) represents not more than 10% of the cladding on each exterior wall of each storey, and
(ii) has a flame-spread rating not more than 75 on any exposed surface, or any surface that would be exposed by
cutting through the material in any direction, or
(b) a combination of the cladding described in Clause (a) and the cladding described in Sentence (1) and Clause (2)(c).
(See Note A-3.1.6.9.(1), (2), (4) and (5))
(5) Except as provided in Sentence (7), cladding on an exterior wall assembly of a building or part thereof permitted to
be of encapsulated mass timber construction and not more than 4 storeys in building height is permitted to consist of
combustible material with a flame-spread rating not more than 75 on any exposed surface, or any surface that would be
exposed by cutting through the material in any direction. (See Note A-3.1.6.9.(1), (2), (4) and (5).)
(6) An exterior wall assembly constructed in conformance with Section 6 of MMAH Supplementary Standard SB-2,
“Fire Performance Ratings” is deemed to satisfy the criteria of Clause (1)(c).
(7) Except as provided in Article 3.2.3.10., where the limiting distance in Table 3.2.3.1.-D or Table 3.2.3.1.-E permits
an area of unprotected openings of not more than 10% of the exposing building face, the construction requirements of
Table 3.2.3.7. shall be met.
(8) A wall assembly conforming to Clause (1)(c) that includes combustible cladding made of fire-retardant-treated
wood shall be tested for fire exposure after the cladding has been subjected to the accelerated weathering test specified in
ASTM D2898, “Standard Practice for Accelerated Weathering of Fire-Retardant-Treated Wood for Fire Testing,”
(9) Where combustible cladding conforming to Clauses (2)(a), (b) or (4)(a) on an exterior wall of a fire compartment is
exposed to combustible cladding conforming to Clause (2)(a), (b) or (4)(b) on an exterior wall of the same fire
compartment or of another fire compartment, and the planes of the two walls are parallel or at an angle less than 135°
measured from the exterior of the building, the different portions of combustible cladding shall
(a) be separated by a horizontal distance of not less than 3 m, and
(b) not be contiguous over more than 2 storeys.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.6.10.Combustible Components in Exterior Walls permalink →
r1 (1) Except as provided in Sentence (2), combustible components, other than those permitted by Article 3.1.6.9., are
permitted to be used in an exterior wall assembly of a building or part thereof permitted to be of encapsulated mass
timber construction provided the wall assembly satisfies the criteria described in Clause 3.1.5.5.(1)(b).
(2) An exterior wall assembly constructed in conformance with Section 6 in MMAH Supplementary Standard SB-2,
“Fire Performance Ratings” is deemed to satisfy the criteria of Sentence (1).
(3) Non-loadbearing wood elements permitted in Article 3.1.5.6. need not conform to Article 3.1.6.3. in a building or
part of a building permitted to be of encapsulated mass timber construction.
Division B – Part 3 24a
3.1.6.11.Nailing Elements permalink →
(1) Wood nailing elements are permitted to be used for the attachment of a material or assembly of materials to provide
an encapsulation rating in a building or part of a building permitted to be of encapsulated mass timber construction,
provided the concealed space created by the wood nailing elements is not more than 25 mm deep.
(2) Except as permitted by Sentence 3.1.6.16.(2) and Article 3.1.6.6., wood nailing elements are permitted to be used for
the attachment of interior finishes in a building or part of a building permitted to be of encapsulated mass timber
construction, provided the concealed space created by the wood nailing elements is not more than 50 mm deep and
(a) exposed surfaces in the concealed space have a flame-spread rating not more than 25, or
(b) the concealed space is filled with noncombustible insulation.
24b Division B – Part 3
3.1.6.12.Combustible Flooring Elements permalink →
(1) Wood members that are more than 50 mm but not more than 300 mm high are permitted to be used for the
construction of a raised platform in a building or part of a building permitted to be of encapsulated mass timber
construction, and they need not conform to Articles 3.1.6.3. and 3.1.6.4., provided
(a) the concealed spaces created by the wood members are divided into compartments by fire blocks in conformance
with Sentence 3.1.11.3.(4), and
(b) the wood members are
(i) applied directly to or set into a noncombustible floor slab, or
(ii) applied directly to a mass timber floor assembly that conforms to the requirements of Article 3.1.6.3.
(2) The upper surface of the mass timber floor assembly referred to in Subclause (1)(b)(ii) is permitted to be
encapsulated only between the wood members by a material or assembly of materials conforming to Sentences 3.1.6.4.(1)
and (2).
(3) The floor system for the raised platform referred to in Sentence (1) is permitted to include a combustible subfloor
and combustible finished flooring.
3.1.6.13.Combustible Stairs permalink →
(1) Wood stairs and landings conforming to the requirements for floor assemblies in Article 3.1.6.3. and Sentences
3.1.6.4.(1) and (2) are permitted in an exit stairwell in a building or part of a building permitted to be of encapsulated
mass timber construction.
(2) Wood stairs in a suite in a building or part of a building permitted to be of encapsulated mass timber construction
need not conform to Articles 3.1.6.3. and 3.1.6.4.
3.1.6.14.Combustible Interior Finishes permalink →
(1) Except as provided in Sentences (2) and (3), combustible interior wall and ceiling finishes referred to in Clause
3.1.13.1.(2)(b) that are not more than 1 mm thick are permitted in a building or part of a building permitted to be of
encapsulated mass timber construction.
r1 (2) Except as provided in Sentences 3.1.6.4.(3), (4), (7) and (8), combustible interior wall finishes, other than foamed
plastics, that are not more than 25 mm thick are permitted in a building or part thereof permitted to be of encapsulated
mass timber construction, provided they have a flame-spread rating not more than 150 on any exposed surface or any
surface that would be exposed by cutting through the material in any direction.
r1 (3) Except as provided in Sentences (4) and 3.1.6.4.(3), (6), (7) and (8), combustible interior ceiling finishes, other than
foamed plastics, that are not more than 25 mm thick are permitted in a building or part thereof permitted to be of
encapsulated mass timber construction, provided they have a flame-spread rating not more than 25 on any exposed
surface, or any surface that would be exposed by cutting through the material in any direction, except that not more than
10% of the ceiling area within each fire compartment is permitted to have a flame-spread rating not more than 150. (See
Note A-3.1.11.3.(3))
(4) Combustible interior ceiling finishes made of fire-retardant-treated wood are permitted in a building or part of a
building permitted to be of encapsulated mass timber construction, provided they are not more than 25 mm thick or are
exposed fire-retardant-treated wood battens.
3.1.6.15.Combustible Elements in Partitions permalink →
(1) Solid lumber partitions not less than 38 mm thick and partitions containing wood framing that do not conform to
Article 3.1.6.3. are permitted in a building or part of a building permitted to be of encapsulated mass timber construction,
provided the partitions are
(a) protected on each face with not less than
(i) a single layer of 12.7 mm thick Type X gypsum board, with all joints either backed or taped and filled,
conforming to ASTM C1396 / C1396M, “Standard Specification for Gypsum Board,” or CAN/CSA-A82.27-
M, “Gypsum Board,”
(ii) a single layer of 19 mm thick fire-retardant-treated wood, on solid lumber partitions, or
(iii) a single layer of 19 mm thick fire-retardant-treated wood, on partitions containing wood framing, with wood
stud cavities filled with noncombustible insulation, and
(b) not installed as enclosures for exits or vertical service spaces.
3.1.6.16.Exposed Construction Materials and Components in Concealed Spaces permalink →
(1) Except as provided in Sentence (2) and Article 3.1.11.7., and except as otherwise provided in this Subsection, only
construction materials and components permitted in noncombustible construction shall be permitted to have exposed
surfaces in concealed spaces within floor, roof and wall assemblies permitted in a building or part of a building permitted
to be of encapsulated mass timber construction.
(2) Exposed surfaces are permitted in a concealed space created by the attachment of a material or assembly of
materials conforming to Sentence 3.1.6.4.(1), provided the concealed space is not more than 25 mm deep.
3.1.6.17.Penetration by Outlet Boxes permalink →
(1) The minimum dimensions stated in Table 3.1.6.3. need not apply at cutouts in vertical or horizontal structural mass
timber elements where outlet boxes are installed in accordance with Article 3.1.9.3. (See also Note A-3.1.9.2.(1))
(2) The exposed surfaces of the cutouts described in Sentence (1) need not be protected in accordance with Sentence
3.1.6.4.(1).
(3) Outlet boxes on opposite sides of a structural mass timber element having a fire-resistance rating shall be separated
by a distance of not less than 600 mm.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.7.Fire-Resistance Ratings
3.1.7.1.Determination of Ratings permalink →
(1) Except as permitted by Sentence (2) and Articles 3.1.7.2. and 3.6.3.5., the rating of a material, assembly of materials
or a structural member that is required to have a fire-resistance rating, shall be determined on the basis of the results of
tests conducted in conformance with CAN/ULC-S101, “Standard Method of Fire Endurance Tests of Building
Construction and Materials.”
(2) A material, assembly of materials or a structural member is permitted to be assigned a fire-resistance rating on the
basis of MMAH Supplementary Standard SB-2, “Fire Performance Ratings.”
3.1.7.2.Exception for Exterior Walls permalink →
(1) The limit on the rise of temperature on the unexposed surface of an assembly as required by the tests referred to in
Sentence 3.1.7.1.(1) shall not apply to an exterior wall that has a limiting distance of 1.2 m or more, provided correction is
made for radiation from the unexposed surface in accordance with Sentence 3.2.3.1.(9).
3.1.7.3.Exposure Conditions for Rating permalink →
(1) Floor, roof and ceiling assemblies shall be rated for exposure to fire on the underside.
(2) Firewalls and interior vertical fire separations shall be rated for exposure to fire on each side.
(3) Exterior walls shall be rated for exposure to fire from inside the building.
3.1.7.4.Minimum Fire-Resistance Rating permalink →
(1) The use of materials or assemblies having a greater fire-resistance rating than required shall impose no obligation to
exceed in whole or in part the minimum fire-resistance ratings required by this Part.
3.1.7.5.Rating of Supporting Construction permalink →
r1 (1) Except as permitted by Sentence (2) and by Articles 3.2.2.20. to 3.2.2.93. for mixed types of construction, all
loadbearing walls, columns and arches in the storey immediately below a floor or roof assembly required to have a fire-
resistance rating shall have a fire-resistance rating not less than that required for the supported floor or roof assembly.
(2) Loadbearing walls, columns and arches supporting a service room or service space need not conform to
Sentence (1).
(3) Except as provided in Sentence (4) and except for noncombustible roof assemblies required by Clauses
3.2.2.51.(2)(c) and 3.2.2.60.(2)(c), if an assembly is required to be of noncombustible construction and have a fire-
resistance rating, it shall be supported by noncombustible construction.
(4) Except for portions of a building constructed in accordance with Article 3.2.2.7. that are required to be of
noncombustible construction, assemblies of noncombustible construction in buildings or portions of buildings permitted
to be of encapsulated mass timber construction are permitted to be supported by encapsulated mass timber construction.
3.1.8.Fire Separations and Closures
3.1.8.1.General Requirements permalink →
(1) Any wall, partition or floor assembly required to be a fire separation shall
(a) except as permitted by Sentence (2), be constructed as a continuous element in conformance with Article 3.1.8.3.,
and
(b) as required in this Part, have a fire-resistance rating as specified. (See Note A-3.1.8.1.(1)(b))
(2) Openings in a fire separation shall be protected with closures, shafts or other means in conformance with Articles
3.1.8.4.to 3.1.8.20. and Subsections 3.1.9. and 3.2.8. (See Note A-3.1.8.1.(2))
3.1.8.2.Combustible Construction Support permalink →
(1) Combustible construction that abuts on or is supported by a noncombustible fire separation shall be constructed so
that its collapse under fire conditions will not cause the collapse of the fire separation.
3.1.8.3.Continuity of Fire Separations permalink →
(1) Except as permitted by Sentence 3.6.4.2.(2), a horizontal service space or other concealed space located above a
required vertical fire separation, including the walls of a vertical shaft, shall be divided at the fire separation by an
equivalent fire separation within the service space.
(2) Except as provided in Sentence (5), the continuity of a fire separation having a fire-resistance rating that abuts
another fire separation, a floor, a ceiling, or a roof shall be maintained by a firestop conforming to Sentence (3). (See
Note A-3.1.8.3.(2))
(3) The firestop required in Sentence (2) shall have an FT rating not less than the fire-resistance rating of the abutting
fire separation when subjected to the fire test method in CAN/ULC-S115, “Standard Method of Fire Tests of Firestop
Systems.”
(4) Except as provided in Sentence (5), joints located in a horizontal plane between a floor and an exterior wall shall be
sealed by a firestop that, when subjected to the fire test method in ASTM E2307, “Standard Test Method for Determining
Fire Resistance of Perimeter Fire Barriers Using Intermediate-Scale, Multi-storey Test Apparatus,” has an F rating not less
than the fire-resistance rating of the horizontal fire separation.
(5) Joints between ceilings and walls, between floors and walls, and between walls at corners need not comply with
Sentences (2) and (4) where such joints consist of gypsum board that is attached to framing members and arranged so as
to restrict the passage of flame and smoke through the joints. (See Note A-3.1.8.3.(5))
3.1.8.4.Determination of Ratings and Classifications permalink →
(1) Except as permitted by Sentences (2) and 3.1.8.16.(1), the fire-protection rating of a closure shall be determined in
accordance with
(a) CAN/ULC-S104, “Standard Method for Fire Tests of Door Assemblies,”
(b) CAN/ULC-S106, “Standard Method for Fire Tests of Window and Glass Block Assemblies,” or
(c) CAN/ULC-S112, “Standard Method for Fire Test of Fire Damper Assemblies.”
(See Articles 3.1.8.17. to 3.1.8.19. for additional requirements for closures.)
(2) Except as permitted by Sentence 3.1.8.12.(1), the fire-protection rating of a closure shall conform to Table 3.1.8.4.
for the required fire-resistance rating of the fire separation.
(3) The leakage rate of smoke dampers and combination smoke/fire dampers shall
(a) be determined in accordance with the applicable provisions in CAN/ULC-S112.1, “Standard for Leakage Rated
Dampers for Use in Smoke Control Systems,” and
(b) conform to Class I, II or III of that standard.
(4) The leakage rate of a door assembly shall be determined in accordance with ANSI/UL-1784, “Standard for Air
Leakage Tests of Door Assemblies and Other Opening Protectives.”
Table 3.1.8.4.
Fire-Protection Rating of Closures
Forming Part of Sentence 3.1.8.4.(2)
Fire-Resistance Rating of Fire Separation Minimum Fire-Protection Rating of Closure
30 min 20 min
45 min 45 min
1h 45 min
1.5 h 1h
2h 1.5 h
3h 2h
4h 3h
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.8.5.Installation of Closures permalink →
(1) Except where fire dampers, window assemblies and glass block are used as closures, closures of the same fire-
protection rating installed on opposite sides of the same opening are deemed to have a fire-protection rating equal to the
sum of the fire-protection ratings of the closures. (See Note A-3.1.8.1.(2))
(2) Except as otherwise specified in this Part, every door, fire damper, window assembly or glass block used as a
closure in a required fire separation shall be installed in conformance with NFPA 80, “Standard for Fire Doors and Other
Opening Protectives.” (See Note A-3.1.8.1.(2))
(3) Except as otherwise specified in this Part, every smoke damper or combination smoke/fire damper used as a closure
in a required fire separation shall be installed in conformance with NFPA 105, “Standard for Smoke Door Assemblies
and Other Opening Protectives.”
(4) If a door is installed so that it could damage the integrity of a fire separation if its swing is unrestricted, door stops
shall be installed to prevent the damage.
(5) Reserved.
(6) A leakage-rated door assembly complying with Sentence 3.1.8.4.(4) shall be installed in
(a) fire separations in protected floor areas described in Clause 3.3.1.7.(1)(b),
(b) fire separations in care or care and treatment occupancies referred to in Sentence 3.3.3.5.(4) and installed in fire
separations in retirement homes referred to in Sentence 3.3.4.11.(4),
(c) except as provided in Sentence (8), fire separations of public corridors serving dwelling units in storeys that are not
sprinklered, and
(d) firewalls that are a horizontal exit referred to in Sentence 3.3.3.5.(3).
(7) Leakage-rated door assemblies required by Sentence (6) shall be installed in accordance with NFPA 105, “Standard
for Smoke Door Assemblies and Other Opening Protectives.”
(8) A leakage-rated door assembly need not be installed where a dwelling unit served by a public corridor has
(a) a second and separate means of egress, or
(b) an open-air balcony that is sized to accommodate the number of occupants for which the dwelling unit is intended.
3.1.8.6.Maximum Openings permalink →
(1) The size of an opening in an interior fire separation required to be protected with a closure shall be not more than
11 m2, with no dimension more than 3.7 m, if a fire compartment on either side of the fire separation is not sprinklered.
(2) The size of an opening in an interior fire separation required to be protected with a closure shall be not more than
22 m2, with no dimension more than 6 m, provided the fire compartments on both sides of the fire separation are
sprinklered.
3.1.8.7.Location of Fire Dampers and Smoke Dampers permalink →
(1) Except as provided in Article 3.1.8.8., a fire damper having a fire-protection rating conforming to
Sentence 3.1.8.4.(2) shall be installed in conformance with Article 3.1.8.10. in ducts or air-transfer openings that
penetrate an assembly required to be a fire separation.
(2) Except as provided in Article 3.1.8.9., a smoke damper or a combination smoke/fire damper shall be installed in
conformance with Article 3.1.8.11. in ducts or air-transfer openings that penetrate an assembly required to be a fire
separation, where the fire separation
(a) separates a public corridor,
(b) contains an egress door referred to in Sentence 3.4.2.4.(2),
(c) serves an assembly, care, care and treatment, detention or residential occupancy, or
(d) is installed to meet the requirements of Clause 3.3.1.7.(1)(b) or Sentence 3.3.3.5.(4). or 3.3.4.11.(4).
3.1.8.8.Fire Dampers Waived permalink →
(1) Except as provided in Sentences (2) to (4), the requirement for fire dampers stated in Sentence 3.1.8.7.(1) is
permitted to be waived for
(a) ducts that serve commercial cooking equipment, (See also Article 6.3.1.6.)
(b) continuous noncombustible ducts having a melting point above 760°C that penetrate a vertical fire separation
required by Sentence 3.3.1.1.(1) between suites of assembly, mercantile, low-hazard industrial, medium-hazard
industrial or high-hazard industrial occupancy,
(c) ducts or air-transfer openings that penetrate a vertical fire separation not required to have a fire-resistance rating, or
(d) noncombustible ducts or air-transfer openings that penetrate a horizontal fire separation not required to have a fire-
resistance rating.
(2) The requirement for fire dampers stated in Sentence 3.1.8.7.(1) is permitted to be waived for noncombustible branch
ducts having a melting point above 760°C that penetrate a fire separation,
(a) provided the ducts
(i) have a cross-sectional area not more than 0.013 m2 and serve only air-conditioning units or combined air-
conditioning and heating units discharging air not more than 1.2 m above the floor, or
(ii) extend not less than 500 mm inside exhaust duct risers that are under negative pressure and in which the
airflow is upward as required by Article 3.6.3.4., or
(b) where the fire separation separates a vertical service space from the remainder of the building, provided each
individual duct exhausts directly to the outdoors at the top of the vertical service space.
(3) In elementary and secondary schools, a continuous noncombustible duct having a melting point above 760°C that
pierces a fire separation having a fire-resistance rating of 30 min need not be equipped with a fire damper at the fire
separation.
(4) In a Group B, Division 3 occupancy which contains sleeping accommodation for not more than 10 persons, which
has not more than six occupants who require assistance in evacuation in case of an emergency and which is equipped with
a fire alarm system, a duct need not be equipped with a fire damper at a fire separation, provided duct-type smoke
detectors have been installed to control smoke circulation as described in Article 3.2.4.12.
3.1.8.9.Smoke Dampers Waived permalink →
(1) Except as provided in Sentence (2), the requirement for smoke dampers or combination smoke/fire dampers stated
in Sentence 3.1.8.7.(2) is permitted to be waived for ducts
(a) that serve commercial cooking equipment, (See also Article 6.3.1.6.)
(b) in which all inlet and outlet openings serve not more than one fire compartment,
(c) that penetrate a vertical fire separation referred to in Clause 3.3.1.7.(1)(b) or in Sentence 3.3.3.5.(4) or 3.3.4.11.(4),
provided,
(i) the movement of air is continuous, and
(ii) the configuration of the air-handling system prevents the recirculation of exhaust or return air under fire
emergency conditions, or
(d) that penetrate a vertical fire separation not required to have a fire-resistance rating and located within the fire
compartment required in Sentence 3.3.3.5.(2).
(2) The requirement for smoke dampers or combination smoke/fire dampers stated in Sentence 3.1.8.7.(2) is permitted to
be waived for noncombustible branch ducts having a melting point above 760°C that penetrate a fire separation,
(a) provided the ducts
(i) have a cross-sectional area not more than 0.013 m² and serve only air-conditioning units or combined air-
conditioning and heating units discharging air not more than 1.2 m above the floor,
(ii) extend not less than 500 mm inside exhaust duct risers that are under negative pressure and in which the
airflow is upward as required by Article 3.6.3.4., or
(iii) are required to function as part of an air handling system used to provide make-up air in accordance with
Sentence 3.2.6.2.(6), or any other system used to limit smoke movement, or
(b) where the fire separation separates a vertical service space from the remainder of the building, provided each
individual duct exhausts directly to the outdoors at the top of the vertical service space.
3.1.8.10.Installation of Fire Dampers permalink →
(1) A fire damper shall be installed in the plane of the fire separation so as to stay in place should the duct become
dislodged during a fire. (See Note A-3.1.8.10.(1))
(2) A fire damper shall be arranged so as to close automatically upon the operation of a fusible link conforming to ULC-
S505, “Standard for Fusible Links for Fire Protection Services,” or other heat-actuated or smoke-actuated device.
(3) A heat-actuated device referred to in Sentence (2) shall
(a) be located where it is readily affected by an abnormal rise of temperature in the duct, and
(b) have a temperature rating approximately 30°C above the maximum temperature that would exist in the system either
with the system in operation or shut down.
(4) A fire damper tested in the vertical or horizontal position shall be installed in the position in which it was tested.
(5) A tightly fitted access door shall be installed for each fire damper to provide access for the inspection of the damper
and the resetting of the release device. (See Note A-3.1.8.10.(5))
3.1.8.11.Installation of Smoke Dampers permalink →
(1) Where smoke dampers are used as a closure in an air-transfer opening, they shall be installed in the plane of the fire
separation.
(2) Where combination smoke/fire dampers are used as a closure in a duct, they shall be installed within 610 mm of the
plane of the fire separation, provided there is no inlet or outlet opening between the fire separation and the damper.
(3) Except as required by a smoke control system, smoke dampers and combination smoke/fire dampers shall be
configured so as to close automatically upon a signal from an adjacent smoke detector located as described in CAN/ULC-
S524, “Standard for Installation of Fire Alarm Systems,” within 1.5 m horizontally of the duct or air-transfer opening in
the fire separation
(a) on both sides of the air-transfer opening, or
(b) in the duct downstream of the smoke damper or combination smoke/fire damper.
(4) Smoke dampers or combination smoke/fire dampers shall be installed in the vertical or horizontal position in which
they were tested.
(5) A tightly fitted access door shall be installed for each smoke damper and combination smoke/fire damper to provide
access for their inspection and the resetting of the release device. (See Note A-3.1.8.10.(5))
3.1.8.12.Twenty-Minute Closures permalink →
(1) A door assembly having a fire-protection rating not less than 20 min is permitted to be used as a closure in
(a) a fire separation not required to have a fire-resistance rating more than 1 h, located between
(i) a public corridor and a suite,
(ii) a corridor and adjacent sleeping rooms, or
(iii) a corridor and adjacent classrooms, offices and libraries in Group A, Division 2 major occupancies, or
(b) a fire separation not required to have a fire-resistance rating more than 45 min, located in a building not more than
3 storeys in building height.
(2) The requirements for noncombustible sills and combustible floor coverings in NFPA 80, “Standard for Fire Doors
and Other Opening Protectives,” do not apply to a door described in Sentence (1).
(3) A door described in Sentence (1) shall have clearances of not more than 6 mm at the bottom and not more than
3 mm at the sides and top.
(4) In elementary and secondary schools, a door assembly conforming to Articles 9.10.13.2. and 9.10.13.3. is permitted
to be used as a closure in a fire separation having a fire-resistance rating of 30 min.
3.1.8.13.Self-Closing Devices permalink →
(1) Except as provided in Sentences (3) to (5) and 3.3.3.2.(5), every door in a fire separation, other than doors to freight
elevators and dumbwaiters, shall be equipped with a self-closing device designed to return the door to the closed position
after each use.
(2) Reserved.
(3) In a building that is not more than 3 storeys in building height, a self-closing device is not required on a door that is
located between a classroom and a corridor providing access to exit from the classroom, except that a self-closing device
is required on a door between a hazardous classroom and the corridor in an elementary or secondary school.
(4) In a building that is not more than 3 storeys in building height, a self-closing device is not required on a door
between a public corridor and an adjacent room or suite of business and personal services occupancy if the door is not
located in,
(a) a dead-end portion of the corridor, or
(b) a corridor that serves a hotel.
(5) Within a fire compartment in a hospital or long-term care home that complies with the requirements of Article
3.3.3.5., a self-closing device is not required on a door that is located between
(a) a patient’s or resident’s sleeping room and a corridor serving the patient’s or resident’s sleeping room, or
(b) a patient’s or resident’s sleeping room and an adjacent room that serves the patient’s or resident’s sleeping room.
3.1.8.14.Hold-Open Devices permalink →
(1) Except as provided in Sentences 3.1.8.10.(2) and 3.1.8.11.(3), a hold-open device is permitted to be used on a
closure in a required fire separation, other than on an exit stair door in a building more than 3 storeys in building height
and on a door for a vestibule required by Article 3.3.5.7., provided the device is designed to release the closure in
conformance with this Article.
(2) Except as provided in Sentences (5) and (6), where the building is provided with a fire alarm system, a hold-open
device permitted by Sentence (1) shall release
(a) in a single-stage system, upon any signal from the fire alarm system, and
(b) in a 2-stage system,
(i) upon any alert signal from the fire alarm system, or
(ii) upon actuation of any adjacent smoke detectors.
(3) Where the building is provided with a fire alarm system, a hold-open device permitted by Sentence (1) shall release
upon a signal from a smoke detector connected to the fire alarm system and located as described in CAN/ULC-S524,
“Standard for Installation of Fire Alarm Systems,” where the hold-open device is used on
(a) an exit door,
(b) a door opening into a public corridor,
(c) an egress door referred to in Sentence 3.4.2.4.(2),
(d) a closure serving an assembly, care, care and treatment, detention, or residential occupancy,
(e) a door in a fire separation referred to in Clause 3.3.1.7.(1)(b) or Sentence 3.3.3.5.(4) or 3.3.4.11.(4), or
(f) a door required to function as part of a smoke control system.
(4) Where the building is not provided with a fire alarm system, a hold-open device permitted by Sentence (1) shall
release upon a signal from a smoke alarm located on either side of the fire separation at ceiling level within 1.5 m
horizontally of the closure opening in the fire separation, where the hold-open device is used on closures described in
Clauses (3)(a) to (e).
(5) Where a hold-open device is used on closures other than those described in Sentences (3) and (4), it is permitted to
be released upon actuation of a heat-actuated device.
(6) A hold-open device used on a door located between a corridor used by the public and an adjacent sleeping room in a
care and treatment occupancy need not release automatically as stated in Sentence (2).
3.1.8.15.Door Latches permalink →
(1) Except as permitted by Sentence 3.3.3.2.(5) and Article 3.3.3.5., a swing-type door in a fire separation shall be
equipped with a positive latching mechanism designed to hold the door in the closed position after each use.
3.1.8.16.Wired Glass and Glass Block permalink →
(1) Except as permitted by Articles 3.1.8.18. and 3.1.8.19. for the separation of exits, an opening in a fire separation
having a fire-resistance rating not more than 1 h is permitted to be protected with fixed wired glass assemblies or glass
blocks installed in conformance with NFPA 80, “Standard for Fire Doors and Other Opening Protectives.” (See also
Article 3.3.2.17.)
(2) Wired glass assemblies permitted by Sentence (1) and described in MMAH Supplementary Standard SB-2, “Fire
Performance Ratings,” are permitted to be used as closures in vertical fire separations without being tested in accordance
with Sentence 3.1.8.4.(1).
(3) Glass blocks permitted by Sentence (1) shall be installed in accordance with Subsection 4.3.2. and reinforced with
steel reinforcement in each horizontal joint.
3.1.8.17.Temperature Rise Limit for Doors permalink →
(1) Except as permitted by Article 3.1.8.19., the maximum temperature rise on the opaque portion of the unexposed side
of a door used as a closure in a fire separation in a location shown in Table 3.1.8.17. shall conform to the Table when
tested in conformance with Sentence 3.1.8.4.(1).
Table 3.1.8.17.
Restrictions on Temperature Rise and Glazing for Closures
Forming Part of Articles of 3.1.8.17. and 3.1.8.18.
Maximum Maximum Maximum Aggregate
Minimum Required Temperature Rise on Aggregate Area Area of Glass Block,
Location Fire-Protection Rating Opaque Portion of of Wired Glass or Wired Glass or Safety
of Door Unexposed Side of Safety Glazing in Glazing Panels Not in
Door, °C a Door, m2 a Door, m2
Between a dead-end corridor and an Less than 45 min No limit No limit No limit
adjacent occupancy where the corridor
provides the only access to exit and is
required to have a fire-resistance rating 45 min 250 after 30 min 0.0645 0.0645
Between an exit enclosure and the
remainder of the floor area in buildings not All ratings No limit 0.8 0.8
more than 3 storeys in building height
45 min 250 after 30 min 0.0645 0.0645
Between an exit enclosure and the
remainder of the floor area (except as 1.5 h 250 after 1 h 0.0645 0.0645
permitted above)
2h 250 after 1 h 0.0645 0.0645
45 min 250 after 30 min 0.0645 0
In a firewall 1.5 h 250 after 30 min 0.0645 0
3h 250 after 1 h 0 0
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.8.18.Area Limits for Wired Glass, Glass Block and Safety Glazing permalink →
(1) Except as permitted by Article 3.1.8.19., the maximum aggregate area of wired glass or safety glazing in a door used
in the locations shown in Table 3.1.8.17. shall conform to the Table. (See Note A-3.1.8.18.(1))
(2) Except as permitted by Article 3.1.8.19., the maximum aggregate area of glass block, wired glass or safety glazing
panels not in a door used in the locations shown in Table 3.1.8.17. shall conform to the Table.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.8.19.Temperature Rise and Area Limits Waived permalink →
(1) The temperature rise limits and glass area limits required by Articles 3.1.8.17. and 3.1.8.18. are waived for a closure
between an exit enclosure and an enclosed vestibule or corridor, provided
(a) the vestibule or corridor is separated from the remainder of the floor area by a fire separation having a fire-
resistance rating not less than 45 min,
(b) the fire separation required by Clause (a) contains no wired glass, glass block or safety glazing within 3 m of the
closure into the exit enclosure, and
(c) the vestibule or corridor contains no occupancy.
(See Note A-3.1.8.19.(1))
3.1.8.20.Sprinkler Protected Glazed Wall Assembly permalink →
(1) A sprinkler protected glazed wall assembly shall be constructed in accordance with the requirements of CAN/ULC-
S136, “Standard Method of Fire Test of Sprinkler Protected Window Systems.”
(2) A sprinkler protected glazed wall assembly shall not be installed in
(a) fire separations requiring a fire-resistance rating of more than 2 h,
(b) a firewall,
(c) a high-hazard industrial occupancy, or
(d) any part of an exit serving
(i) a floor area subject to the requirements of Subsection 3.2.6.,
(ii) a care occupancy,
(iii) a care and treatment occupancy,
(iv) a detention occupancy, or
(v) a residential occupancy.
(3) Where a sprinkler protected glazed wall assembly is installed in an exit fire separation permitted in Sentence (2),
(a) the building shall be sprinklered throughout, and
(b) the exits protected with the sprinkler protected glazed wall assemblies shall not comprise more than one-half of the
required number of exits from any floor area.
3.1.9.Penetrations in Fire Separations and Fire-Rated Assemblies
3.1.9.1.Firestops permalink →
(1) Except as provided in Sentences (2) to (7) and Article 3.1.9.3., penetrations of a fire separation or a membrane
forming part of an assembly required to have a fire-resistance rating shall be
(a) sealed by a firestop that, when subjected to the fire test method in CAN/ULC-S115, “Standard Method of Fire Tests
of Firestop Systems,” has an F rating not less than the required fire-resistance rating of the fire separation, or
(b) cast-in-place, where the item penetrating the fire separation is steel, ferrous, copper, concrete or masonry. (See Note
A-3.1.9.1.(1)(b))
(See also Article 3.1.9.4. for requirements regarding penetrations by combustible drain, waste and vent piping.)
(2) Except as permitted in Sentence (6), penetrations of a firewall or a horizontal fire separation that is required to have
a fire-resistance rating in conformance with Article 3.2.1.2. shall be sealed at the penetration by a firestop that, when
subjected to the fire test method in CAN/ULC-S115, “Standard Method of Fire Tests of Firestop Systems,” has an FT
rating not less than the fire-resistance rating for the fire separation.
(3) Except as permitted in Sentences (6) and (7), penetrations of a fire separation in conformance with Sentence
3.6.4.2.(2) shall be sealed by a firestop that, when subjected to the fire test method in CAN/ULC-S115, “Standard Method
of Fire Tests of Firestop Systems,” has an FT rating not less than the fire-resistance rating for the fire separation of the
assembly.
(4) Sprinklers are permitted to penetrate a fire separation or a membrane forming part of an assembly required to have a
fire-resistance rating without having to meet the firestop requirements of Sentences (1) to (3), provided the annular space
created by the penetration of a fire sprinkler is covered by a metal escutcheon plate in accordance with NFPA 13,
“Standard for the Installation of Sprinkler Systems.”
(5) Unless specifically designed with a firestop, fire dampers are permitted to penetrate a fire separation or a membrane
forming part of an assembly required to have a fire-resistance rating without having to meet the firestop requirements of
Sentences (1) to (3), provided the fire damper is installed in conformance with NFPA 80, “Standard for Fire Doors and
Other Opening Protectives.”
(6) Service equipment penetrations through a horizontal fire separation having a fire-resistance rating as described in
Sentences (2) and (3) that are contained within the cavity of a wall above and below the horizontal fire separation are
permitted to be sealed at the penetration by a firestop that, when subjected to the fire test method in CAN/ULC-S115,
“Standard Method of Fire Tests of Firestop Systems,” has an F rating not less than the fire-resistance rating for the fire
separation.
(7) Service equipment penetrations through a horizontal fire separation having a fire-resistance rating as described in
Sentence (3) are permitted to be sealed at the penetration by a firestop that, when subjected to the fire test method in
CAN/ULC-S115, “Standard Method of Fire Tests of Firestop Systems,” has an F rating not less than the fire-resistance
rating for the fire separation, provided the penetration
(a) is contained within the concealed space of a floor or ceiling assembly having a fire-resistance rating,
(b) is located above a ceiling membrane that is a horizontal fire separation, or
(c) is contained within a horizontal service space conforming to Subsection 3.6.4. that is directly above or below the
floor.
3.1.9.2.Service Equipment Penetrations permalink →
(1) Ducts, electrical outlet boxes, pipes, totally enclosed raceways, optical fibre cables, electrical wires and cables, and
other similar service equipment are permitted to penetrate a fire separation or a membrane forming part of an assembly
required to have a fire-resistance rating, provided they are protected at the penetration with a firestop conforming to
Sentence 3.1.9.1.(1). (See Note A-3.1.9.2.(1))
(2) Combustible totally enclosed raceways that are embedded in a concrete floor slab are permitted in an assembly
required to have a fire-resistance rating, provided the concrete cover between the raceway and the bottom of the slab is
not less than 50 mm.
3.1.9.3.Penetration by Outlet Boxes (See Note A-3.1.9.3.) (See also Note A-3.1.9.2.(1)) permalink →
(1) Except as provided in Sentence (3), outlet boxes are permitted to penetrate the membrane of an assembly required to
have a fire-resistance rating, provided they are sealed at the penetration by a firestop that has an FT rating not less than the
fire-resistance rating of the fire separation when subjected to the fire test method in CAN/ULC-S115, “Standard Method
of Fire Tests of Firestop Systems.”
(2) Combustible outlet boxes are permitted to penetrate the membrane of an assembly required to have a fire-resistance
rating, provided they are sealed at the penetration by a firestop that, when subjected to the fire test method in CAN/ULC-
S115, “Standard Method of Fire Tests of Firestop Systems,” has an FT rating not less than the fire-resistance rating for
the fire separation.
(3) Except as provided in Sentences 3.1.9.1.(2) and (3), noncombustible outlet boxes that penetrate a vertical fire
separation or a membrane forming part of an assembly required to have a fire-resistance rating need not conform to
Sentence (1), provided
(a) they do not exceed,
(i) 0.016 m² in area, and
(ii) an aggregate area of 0.065 m² in any 9.3 m² of surface area, and
(b) the annular space between the membrane and noncombustible electrical outlet boxes does not exceed 3 mm.
(4) Outlet boxes on opposite sides of a vertical fire separation having a fire-resistance rating shall be separated by
(a) a horizontal distance of not less than 600 mm,
(b) a fire block conforming to Article 3.1.11.7., or
(c) a firestop installed on each outlet box that has an FT rating not less than the fire-resistance rating of the fire
separation when subjected to the fire test method in CAN/ULC-S115, “Standard Method of Fire Tests of Firestop
Systems.”
3.1.9.4.Combustible Piping Penetrations permalink →
(1) Combustible sprinkler piping is permitted to penetrate a fire separation provided the fire compartments on each side
of the fire separation are sprinklered.
(2) Combustible water distribution piping is permitted to penetrate a fire separation that is required to have a fire-
resistance rating, provided the piping is protected at the penetration with a firestop in conformance with Clause (4)(a) or
(b).
(3) Except as permitted by Sentences (4), (5), (7) and (8), combustible piping shall not be used in a drain, waste and
vent piping system if any part of that system penetrates
(a) a fire separation required to have a fire-resistance rating, or
(b) a membrane that forms part of an assembly required to have a fire-resistance rating.
(4) Combustible drain, waste and vent piping is permitted to penetrate a fire separation required to have a fire-
resistance rating or a membrane that forms part of an assembly required to have a fire-resistance rating, provided
(a) except as provided in Clause (b), the piping is sealed at the penetration by a firestop that has an F rating not less than
the fire-resistance rating required for the fire separation when subjected to the fire test method in CAN/ULC-S115,
“Standard Method of Fire Tests of Firestop Systems,”
(b) in buildings more than 3 storeys in building height, the piping is sealed at the penetration by a firestop that has an F
rating not less than the fire-resistance rating required for the fire separation when subjected to the fire test method in
CAN/ULC-S115, “Standard Method of Fire Tests of Firestop Systems,” with a pressure differential of 50 Pa
between the exposed and unexposed sides, with the higher pressure on the exposed side, and
(c) the piping is not located in a vertical service space.
(5) Combustible drain, waste and vent piping is permitted on one side of a vertical fire separation provided it is not
located in a vertical service space.
(6) Combustible piping for central vacuum systems is permitted to penetrate a fire separation, provided the installation
conforms to the requirements that apply to combustible drain, waste and vent piping specified in Sentence (4).
(7) Except as provided in Sentence (8), penetrations of a fire separation that incorporate transitions between
combustible and noncombustible drain, waste and vent piping shall be sealed by a firestop that has an F rating not less
than the fire-resistance rating required for the fire separation when subjected to the fire test method in CAN/ULC-S115,
“Standard Method of Fire Tests of Firestop Systems,” with a pressure differential of 50 Pa between the exposed and
unexposed sides, with the higher pressure on the exposed side.
(8) Transitions between vertical noncombustible drain, waste and vent piping and combustible branches for drain, waste
and vent piping are permitted on either side of a fire separation, provided they are not located in a vertical service space.
(See Note A-3.1.9.4.(8))
(9) Combustible piping not more than 25 mm in diameter containing chlorine gas is permitted to penetrate a fire
separation between a chlorine gas service room built in conjunction with a public pool or public spa and the remainder of
the building, provided the piping is sealed at the penetration by a firestop in conformance with Clause 3.1.9.1.(1)(a).
3.1.9.5.Openings Through a Membrane Ceiling permalink →
(1) A membrane ceiling forming part of an assembly assigned a fire-resistance rating on the basis of MMAH
Supplementary Standard SB-2, “Fire Performance Ratings,” is permitted to be penetrated by openings leading into ducts
within the ceiling space provided
(a) the ducts are sheet steel, and
(b) the number of openings and their protection conform to the requirements of MMAH Supplementary Standard SB-2,
“Fire Performance Ratings.”
(2) Fire stop flaps in ceiling membranes required in Sentence (1) shall conform to CAN/ULC-S112.2, “Standard
Method of Fire Test of Ceiling Firestop Flap Assemblies.”
3.1.9.6.Plenums permalink →
(1) A ceiling assembly used as a plenum shall conform to Article 3.6.4.3.
3.1.10.Firewalls
3.1.10.1.Prevention of Firewall Collapse permalink →
(1) Except as permitted by Sentence (2), the connections and supports for structural framing members that are
connected to or supported on a firewall and have a fire-resistance rating less than that required for the firewall, shall be
designed so that the failure of the framing systems during a fire will not affect the integrity of the firewall during the fire.
(2) Sentence (1) does not apply to a firewall consisting of two separate wall assemblies each tied to its respective
building frame but not to each other, provided each wall assembly is
(a) a fire separation having one-half of the fire-resistance rating required for the firewall by Sentences 3.1.10.2.(1) and
(2), and
(b) designed so that the collapse of one wall assembly will not cause collapse of the other.
(3) A firewall is permitted to be supported on the structural frame of a building of noncombustible construction
provided the supporting frame has a fire-resistance rating not less than that required for the firewall.
(4) Piping, ducts and totally enclosed noncombustible raceways shall be installed so that their collapse will not cause
collapse of the firewall.
3.1.10.2.Rating of Firewalls permalink →
(1) A firewall that separates a building or buildings with floor areas containing a Group E or a Group F, Division 1 or 2
major occupancy shall be constructed as a fire separation of noncombustible construction having a fire-resistance rating
not less than 4 h, except that where the upper portion of a firewall separates floor areas containing other than Group E or
Group F, Division 1 or 2 major occupancies, the fire-resistance rating of the upper portion of the firewall is permitted to
be not less than 2 h.
(2) A firewall that separates a building or buildings with floor areas containing major occupancies other than Group E
or Group F, Division 1 or 2 shall be constructed as a fire separation of noncombustible construction having a fire-
resistance rating not less than 2 h.
(3) Except as permitted by Sentence (4), the required fire-resistance rating of a firewall, except for closures, shall be
provided by masonry or concrete.
(4) A firewall permitted to have a fire-resistance rating not more than 2 h need not be constructed of masonry or
concrete provided
(a) the assembly providing the fire-resistance rating is protected against damage that would compromise the integrity of
the assembly,
(b) the design conforms to Article 4.1.5.17.,
(c) the level of performance of the firewall is not less than of masonry or concrete in the areas of
(i) performance during fire conditions,
(ii) mechanical damage during the normal use of the building, and
(iii) resistance to damage from moisture,
(d) the firewall separates buildings or buildings with floor areas that do not contain
(i) a Group B, Division 1 major occupancy, or
(ii) a Group B, Division 2 major occupancy, and
(e) the firewall does not separate a building regulated by the provisions of Subsection 3.2.6. or a building within the
scope of Article 3.2.2.51. or 3.2.2.60. from another building unless the buildings on both sides of the firewall are
sprinklered.
(See Note A-3.1.10.2.(4))
3.1.10.3.Continuity of Firewalls permalink →
(1) A firewall shall extend from the ground continuously through, or adjacent to, all storeys of a building or buildings so
separated, except that a firewall located above a basement storage garage conforming to Article 3.2.1.2. is permitted to
commence at the floor assembly immediately above the storage garage. (See also Sentence 3.1.10.1.(3))
(2) A firewall is permitted to terminate on the underside of a reinforced concrete roof slab provided
(a) the roof slab on both sides of the firewall has a fire-resistance rating not less than
(i) 1 h if the firewall is required to have a fire-resistance rating not less than 2 h, or
(ii) 2 h if the firewall is required to have a fire-resistance rating not less than 4 h, and
(b) there are no concealed spaces within the roof slab in that portion immediately above the firewall.
3.1.10.4.Parapets permalink →
(1) Except as permitted by Sentences (2) and 3.1.10.3.(2), a firewall shall extend above the roof surface to form a
parapet not less than
(a) 150 mm high for a firewall required to have a fire-resistance rating not less than 2 h, and
(b) 900 mm high for a firewall required to have a fire-resistance rating not less than 4 h.
(2) A firewall that separates 2 buildings with roofs at different elevations need not extend above the upper roof surface
to form a parapet, provided the difference in elevation between the roofs is more than 3 m.
3.1.10.5.Maximum Openings permalink →
(1) Openings in a firewall shall conform to the size limits described in Article 3.1.8.6.
(2) The aggregate width of openings in a firewall within a storey shall be not more than 25% of the entire length of the
firewall.
3.1.10.6.Exposure Protection for Adjacent Walls permalink →
(1) The requirements of Article 3.2.3.14. shall apply to the external walls of 2 buildings that meet at a firewall at an
angle less than 135.
3.1.10.7.Combustible Projections permalink →
(1) Combustible material shall not extend across the end of a firewall but is permitted to extend across a roof above a
firewall that is terminated in conformance with Sentence 3.1.10.3.(2).
(2) If buildings are separated by a firewall, combustible projections on the exterior of one building, including balconies,
platforms, canopies, eave projections and stairs, that extend outward beyond the end of the firewall, shall not be permitted
within 2.4 m of combustible projections and window or door openings of the adjacent building. (See also Article 3.2.3.6.)
3.1.11.Fire Blocks in Concealed Spaces
3.1.11.1.Separation of Concealed Spaces permalink →
(1) Concealed spaces in interior wall, ceiling and crawl spaces shall be separated from concealed spaces in exterior
walls and attic or roof spaces by fire blocks conforming to Article 3.1.11.7.
3.1.11.2.Fire Blocks in Wall Assemblies permalink →
(1) Except as permitted by Sentence (2), fire blocks conforming to Article 3.1.11.7. shall be provided to block off
concealed spaces within a wall assembly
(a) at every floor level,
(b) at every ceiling level where the ceiling forms part of an assembly required to have a fire-resistance rating, and
(c) so that the maximum horizontal dimension is not more than 20 m and the maximum vertical dimension is not more
than 3 m.
(2) Fire blocks conforming to Sentence (1) are not required provided
(a) the wall space is filled with insulation,
(b) the exposed construction materials and any insulation within the wall space are noncombustible,
(c) the exposed materials within the wall space, including insulation but not including wiring, piping or similar services,
have a flame-spread rating not more than 25 on any exposed surface, or on any surface that would be exposed by
cutting through the material in any direction, and fire blocks are installed so that the vertical distance between them
is not more than 10 m, or
(d) the insulated wall assembly contains not more than one concealed air space, and the horizontal thickness of that air
space is not more than 25 mm.
3.1.11.3.Fire Blocks Between Nailing and Supporting Elements permalink →
(1) In a building required to be of noncombustible construction, a concealed space in which there is an exposed ceiling
finish with a flame-spread rating more than 25, shall be provided with fire blocks conforming to Article 3.1.11.7. between
wood nailing elements, so that the maximum area of the concealed space is not more than 2 m 2.
(2) In a building required to be of noncombustible construction, fire blocks conforming to Article 3.1.11.7. shall be
provided in the concealed spaces created by the wood members permitted by Sentence 3.1.5.10.(2), so that the maximum
area of a concealed space is not more than 10 m 2.
(3) In a building or part of a building permitted to be of encapsulated mass timber construction, a concealed space in
which there is an exposed ceiling finish with a flame-spread rating more than 25 shall be provided with fire blocks
conforming to Article 3.1.11.7. between wood nailing elements so that the maximum area of the concealed space is not
more than 2 m2. (See Note A-3.1.11.3.(3))
(4) In a building or part of a building permitted to be of encapsulated mass timber construction, fire blocks conforming
to Article 3.1.11.7. shall be provided in the concealed spaces created by the wood members permitted by Sentence
3.1.6.12.(1) so that the maximum area of a concealed space is not more than 10 m2.
3.1.11.4.Fire Blocks Between Vertical and Horizontal Spaces permalink →
(1) Fire blocks conforming to Article 3.1.11.7. shall be provided
(a) at all interconnections between concealed vertical and horizontal spaces in interior coved ceilings, drop ceilings and
soffits in which the exposed construction materials within the space have a flame-spread rating more than 25, and
(b) at the end of each run and at each floor level in concealed spaces between stair stringers in which the exposed
construction materials within the space have a flame-spread rating more than 25.
3.1.11.5.Fire Blocks in Horizontal Concealed Spaces permalink →
(1) Except for crawl spaces conforming to Sentence 3.1.11.6.(1) and as required in Sentence (3), horizontal concealed
spaces within a floor assembly or roof assembly of combustible construction, in which sprinklers are not installed, shall
be separated by construction conforming to Article 3.1.11.7. into compartments
(a) not more than 600 m2 in area with no dimension more than 60 m, if the exposed construction materials within the
space have a flame-spread rating not more than 25, and
(b) not more than 300 m2 in area with no dimension more than 20 m, if the exposed construction materials within the
space have a flame-spread rating more than 25.
(See Note A-3.1.11.5.(1))
(2) A concealed space in an exterior cornice, a mansard style roof, a balcony or a canopy in which exposed construction
materials within the space have a flame-spread rating more than 25, shall be separated by construction conforming to
Article 3.1.11.7.
(a) at locations where the concealed space extends across the ends of required vertical fire separations, and
(b) so that the maximum dimension in the concealed space is not more than 20 m.
(3) Except as provided by Sentence (5), in buildings or parts thereof conforming to Article 3.2.2.51. or 3.2.2.60.,
horizontal concealed spaces within a floor assembly or roof assembly of combustible construction shall be separated by
construction conforming to Article 3.1.11.7. into compartments that are
(a) not more than 600 m2 in area with no dimension more than 60 m, if the exposed construction materials within the
space have a flame-spread rating not more than 25, and
(b) not more than 300 m2 in area with no dimension more than 20 m, if the exposed construction materials within the
space have a flame-spread rating more than 25.
(See Note A-3.1.11.5.(3) and (4))
r1 (4) Except for crawl spaces conforming to Sentence 3.1.11.6.(1) and except as provided in Sentence (5), in buildings or
parts thereof conforming to Article 3.2.2.48., 3.2.2.57. or 3.2.2.93., horizontal concealed spaces within a floor assembly
or roof assembly of encapsulated mass timber construction shall be separated by construction conforming to Article
3.1.11.7.into compartments that are permalink →
(a) not more than 600 m2 in area with no dimension more than 60 m, if the exposed construction materials within the
space have a flame-spread rating not more than 25, and
(b) not more than 300 m2 in area with no dimension more than 20 m, if the exposed construction materials within the
space have a flame-spread rating more than 25.
(See Note A-3.1.11.5.(3) and (4))
(5) Fire blocks conforming to Sentences (3) and (4) are not required where the horizontal concealed space within the
floor or roof assembly is entirely filled with noncombustible insulation such that any air gap between the top of the
insulation and the floor or roof deck does not exceed 50 mm.
3.1.11.6.Fire Blocks in Crawl Spaces permalink →
(1) A crawl space that is not considered as a basement by Article 3.2.2.9. and in which sprinklers are not installed shall
be separated by construction conforming to Article 3.1.11.7. into compartments not more than 600 m 2 in area with no
dimension more than 30 m.
3.1.11.7.Fire Block Materials permalink →
(1) Except as permitted by Sentences (2) to (5) and (8), fire blocks shall remain in place and prevent the passage of
flames for not less than 15 min when subjected to the standard fire exposure in CAN/ULC-S101, “Standard Method of
Fire Endurance Tests of Building Construction and Materials.”
(2) Gypsum board not less than 12.7 mm thick and sheet steel not less than 0.38 mm thick need not be tested in
conformance with Sentence (1) provided all joints have continuous support.
(3) In a building required to be of noncombustible construction, wood nailing elements described in Article 3.1.5.8.
need not be tested in conformance with Sentence (1).
(4) In a building or part of a building permitted to be of encapsulated mass timber construction, wood nailing elements
referred to in Article 3.1.6.11. need not be tested in conformance with Sentence (1).
(5) In a building permitted to be of combustible construction, in a combustible roof system permitted by Sentences
3.1.5.3.(2) and 3.1.6.7.(1), and in a raised platform permitted by Sentence 3.1.5.10.(2) or 3.1.6.12.(1), fire blocks are
permitted to be
(a) solid lumber or a structural composite lumber product conforming to ASTM D5456, “Standard Specification for
Evaluation of Structural Composite Lumber Products,” not less than 38 mm thick,
(b) phenolic bonded plywood, OSB, waferboard or oriented strandboard not less than 12.5 mm thick with joints
supported, or
(c) two thicknesses of lumber or a structural composite lumber product conforming to ASTM D5456, “Standard
Specification for Evaluation of Structural Composite Lumber Products,” each not less than 19 mm thick with joints
staggered, where the width or height of the concealed space requires more than one piece of lumber or structural
composite lumber product not less than 38 mm thick to block off the space.
(6) Openings through materials referred to Sentences (1) to (5) shall be protected to maintain the integrity of the
construction.
(7) Where materials referred to Sentences (1) to (5) are penetrated by construction elements or by service equipment, a
firestop shall be used to seal the penetration. (See Note A-3.1.11.7.(7))
(8) In buildings permitted to be of combustible construction, semi-rigid fibre insulation board produced from glass, rock
or slag is permitted to be used to block the vertical space in a double stud wall assembly formed at the intersection of the
floor assembly and the walls, provided the width of the vertical space does not exceed 25 mm and the insulation board
(a) has a density not less than 45 kg/m3,
(b) is securely fastened to one set of studs,
(c) extends from below the bottom of the top plates in the lower storey to above the top of the bottom plate in the upper
storey, and
(d) completely fills the portion of the vertical space between the headers and between the wall plates.
(See Note A-3.1.11.7.(8))
3.1.12.Flame-Spread Rating and Smoke Developed Classification
3.1.12.1.Determination of Ratings permalink →
(1) Except as required by Sentence (2) and as permitted by Sentence (3), the flame-spread rating and smoke developed
classification of a material, assembly, or structural member shall be determined on the basis of not less than three tests
conducted in conformance with CAN/ULC-S102, “Standard Method of Test for Surface Burning Characteristics of
Building Materials and Assemblies.”
(2) The flame-spread rating and smoke developed classification of a material or assembly shall be determined on the
basis of not less than three tests conducted in conformance with CAN/ULC-S102.2, “Standard Method of Test for Surface
Burning Characteristics of Flooring, Floor Coverings, and Miscellaneous Materials and Assemblies,” if the material or
assembly
(a) is designed for use in a relatively horizontal position with only its top surface exposed to air,
(b) cannot be tested in conformance with Sentence (1) without the use of supporting material that is not representative
of the intended installation, or
(c) is thermoplastic.
(3) A material, assembly, or structural member is permitted to be assigned a flame-spread rating and smoke developed
classification on the basis of MMAH Supplementary Standard SB-2, “Fire Performance Ratings.”
3.1.13.Interior Finish
3.1.13.1.Interior Finishes, Furnishings and Decorative Materials permalink →
(1) Except as otherwise provided in this Subsection, interior finishes, furnishings and decorative materials shall conform
to
(a) the Fire Code made under the Fire Protection and Prevention Act, 1997, or
(b) Section 2.3. of Division B of the CCBFC NRC-CONST-56437E, “National Fire Code of Canada”, in the absence of
regulations referred to in Clause (a).
(2) Interior finish material shall include any material that forms part of the interior surface of a floor, wall, partition or
ceiling, including
(a) interior cladding of plaster, wood or tile,
(b) surfacing of fabric, paint, plastic, veneer or wallpaper,
(c) doors, windows and trim,
(d) lighting elements, such as light diffusers and lenses forming part of the finished surface of the ceiling, and
(e) carpet material that overlies a floor that is not intended as the finished floor.
3.1.13.2.Flame-Spread Rating permalink →
(1) Except as otherwise required or permitted by this Subsection, the flame-spread rating of interior wall and ceiling
finishes, including glazing and skylights, shall be not more than 150 and shall conform to Table 3.1.13.2.
(2) Except as permitted by Sentence (3), doors, other than those in Group A, Division 1 occupancies, need not conform
to Sentence (1) provided they have a flame-spread rating not more than 200. (See Note A-3.1.13.2.(2))
(3) Doors within a dwelling unit need not conform to Sentences (1) and (2).
Table 3.1.13.2.
Flame-Spread Ratings
Forming Part of Sentence 3.1.13.2.(1)
Maximum Flame-Spread Rating for
Occupancy, Location or Element Walls and Ceilings
Sprinklered Not Sprinklered
Group A, Division 1 occupancies, including doors, skylights, glazing and light diffusers
150 75
and lenses
Group B occupancies 150 75
Exits(1) 25 25
Lobbies described in Sentence 3.4.4.2.(2) 25 25
Covered vehicular passageways, except for roof assemblies of heavy timber construction in the
25 25
passageways
Vertical service spaces 25 25
Notes to Table 3.1.13.2.:
(1) See Articles 3.1.13.8. and 3.1.13.10.
(4) Up to 10% of the total wall area and 10% of the total ceiling area of a wall or ceiling finish that is required by
Sentence (1) to have a flame-spread rating less than 150 is permitted to have a flame-spread rating not more than 150,
except that up to 25% of the total wall area of lobbies described in Sentence 3.4.4.2.(2) is permitted to have a flame-
spread rating not more than 150.
(5) Except in the case of Group A, Division 1 occupancies, combustible doors, skylights, glazing and light diffusers and
lenses shall not be considered in the calculation of wall and ceiling areas described in Sentence (4).
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.13.3.Bathrooms in Residential Suites permalink →
(1) The flame-spread rating of interior wall and ceiling finishes for a bathroom within a suite of residential occupancy
shall be not more than 200.
(2) Plumbing fixtures shall have a flame-spread rating not more than 200.
3.1.13.4.Light Diffusers and Lenses permalink →
(1) The flame-spread rating of combustible light diffusers and lenses in all occupancies other than Group A, Division 1
is permitted to be more than the flame-spread rating limits required elsewhere in this Subsection, provided the light
diffusers and lenses
(a) have a flame-spread rating not more than 250 and a smoke developed classification not more than 600 when tested
in conformance with CAN/ULC-S102.2, “Standard Method of Test for Surface Burning Characteristics of Flooring,
Floor Coverings, and Miscellaneous Materials and Assemblies,”
(b) fall to the bottom of the test apparatus before igniting when tested in conformance with CAN/ULC-S102.3,
“Standard Method of Fire Test of Light Diffusers and Lenses,”
(c) are not prevented from falling from the ceiling by construction located beneath the elements, and
(d) are not used in a corridor that is required to be separated from the remainder of the building by a fire separation or
in an exit shaft unless individual diffusers or lenses are not more than 1 m 2 in area and are not less than 1.2 m apart.
3.1.13.5.Skylights permalink →
(1) Individual combustible skylights in a corridor that is required to be separated from the remainder of the building by a
fire separation shall be not more than 1 m2 in area and not less than 1.2 m apart.
3.1.13.6.Corridors permalink →
(1) Except as permitted by Sentences (2) and (3), the flame-spread rating shall be not more than 75 for the interior wall
finish of
(a) a public corridor,
(b) a corridor used by the public in,
(i) an assembly occupancy, or
(ii) a care, care and treatment or detention occupancy,
(c) a corridor serving classrooms, or
(d) a corridor serving sleeping rooms in a care, care and treatment or detention occupancy.
(2) The flame-spread rating for corridors specified in Sentence (1) is permitted to be waived, provided the flame-spread
rating is not more than
(a) 25 on the upper half of the wall, and
(b) 150 on the lower half of the wall.
(3) Where the floor area is sprinklered throughout, the flame-spread ratings for corridors specified in Sentences (1) and
(2) shall be not more than 150.
(4) The flame-spread ratings specified in Sentences (1), (2) and (3) apply to occupancies in the corridor as well as to the
corridor itself.
(5) Except as provided in Sentence (6), the interior ceiling finish of corridors and occupancies referred to in Sentences
(1) and (4) shall have a flame-spread rating not more than 25.
(6) Where the floor area is sprinklered throughout, the flame-spread rating of the interior ceiling finish of corridors and
occupancies referred to in Sentences (1) and (4) shall be not more than 150.
3.1.13.7.High Buildings permalink →
(1) Except as permitted by Sentences (2) to (4), the interior wall, ceiling and floor finishes in a building regulated by the
provisions of Subsection 3.2.6. shall conform to the flame-spread rating requirements in Articles 3.1.13.2. to 3.1.13.6.
and 3.1.13.11. and to the flame-spread rating and smoke developed classification values in Table 3.1.13.7.
(2) Except for a building of Group B major occupancy and elevator cars, the flame-spread rating and smoke developed
classification of interior wall, floor and ceiling finishes need not conform to the values in Table 3.1.13.7., provided the
building is sprinklered.
(3) Trim and millwork in an exit stairway, a vestibule to an exit stairway, a lobby described in Sentence 3.4.4.2.(2), or a
corridor not within a suite need not conform to the flame-spread rating and smoke developed classification requirements
of Sentence (1), provided they have
(a) a flame-spread rating not more than 150,
(b) a smoke developed classification not more than 300, and
(c) an aggregate area not more than 10% of the area of the wall or ceiling on which they occur.
Table 3.1.13.7.
Flame-Spread Rating and Smoke Developed Classification in High Buildings
Forming Part of Sentences 3.1.13.7.(1) and (2)
Maximum Smoke Developed
Maximum Flame-Spread Rating
Classification
Location or Element
Wall Ceiling Floor Wall Ceiling Floor
Surface Surface(1) Surface Surface Surface(1) Surface
Exit stairways, vestibules to exit stairs and lobbies
25 25 25 50 50 50
described in Sentence 3.4.4.2.(2)
Corridors not within suites (2) (2) 300 100 50 500
Elevator cars 75 75 300 450 450 450
Elevator vestibules 25 25 300 100 100 300
Service spaces and service rooms 25 25 25 50 50 50
Other locations and elements (2) (2) No limit 300 50 No limit
Notes to Table 3.1.13.7.:
(1) See Sentence 3.1.13.4.(1) for lighting elements.
(2) Other requirements of this Part apply.
(4) A door serving an exit stairway, a vestibule to an exit stairway, a lobby described in Sentence 3.4.4.2.(2), or a corridor
not within a suite need not conform to the flame-spread rating and smoke developed classification requirements of
Sentence (1) provided
(a) it has a flame-spread rating not more than 200,
(b) it has a smoke developed classification not more than 300, and
(c) the aggregate area of all doors is not more than 10% of the area of the wall in which they are located.
(5) Except as permitted in Sentences (6) to (8), plumbing fixtures in a building regulated by the provisions of Subsection
3.2.6. shall have a smoke developed classification not more than 300.
(6) A plumbing fixture that is not located in a Group B occupancy need not comply with Sentence (5) if the building is
sprinklered throughout.
(7) A plumbing fixture may have a smoke developed classification more than 300 but not more than 500 if,
(a) it is in a room where the wall surfaces have a smoke developed classification not more than 200, and
(b) it is located in,
(i) a Group C occupancy, or
(ii) a Group B occupancy and the building is sprinklered throughout.
(8) A therapeutic bathing system in a Group B occupancy need not comply with Sentence (5) if the room in which it is
located,
(a) does not open directly into patients’ or residents’ sleeping rooms, and
(b) is sprinklered.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.13.8.Noncombustible Construction permalink →
(1) In a building required to be of noncombustible construction,
(a) the flame-spread ratings required by Subsection 3.1.5. shall apply in addition to the requirements in this Subsection,
and
(b) the flame-spread ratings for exits in this Subsection shall also apply to any surface in the exit that would be exposed
by cutting through the material in any direction, except that this requirement does not apply to doors, heavy timber
construction in a sprinklered building and fire-retardant-treated wood.
3.1.13.9.Underground Walkways permalink →
(1) Except for paint, the interior wall and ceiling finishes of an underground walkway shall be of noncombustible
materials.
3.1.13.10.Exterior Exit Passageway permalink →
(1) The wall and ceiling finishes of an exterior exit passageway that provides the only means of egress from the rooms
or suites it serves, including the soffit beneath and the guard on the passageway, shall have a flame-spread rating not
more than 25, except that a flame-spread rating not more than 150 is permitted for up to 10% of the total wall area and for
up to 10% of the total ceiling area.
3.1.13.11.Elevator Cars permalink →
(1) The wall and ceiling surfaces of elevator cars shall have a flame-spread rating not more than 75.
(2) The wall, ceiling and floor surfaces of elevator cars shall have a smoke developed classification not more than 450.
3.1.13.12.Encapsulated Mass Timber Construction permalink →
(1) In a building or part of a building permitted to be of encapsulated mass timber construction,
(a) the flame-spread ratings required by Subsection 3.1.6. shall apply in addition to the requirements in this Subsection,
and
(b) the flame-spread ratings for exits required by this Subsection shall also apply to any surface in the exit that would be
exposed by cutting through the material in any direction, except that this requirement does not apply to doors,
structural mass timber elements conforming to Sentence 3.1.6.4.(3), heavy timber construction and fire-retardant-
treated wood.
3.1.14.Roof Assemblies
3.1.14.1.Fire-Retardant-Treated Wood Roof Systems permalink →
(1) If a fire-retardant-treated wood roof system is used to comply with the requirements of Subsection 3.2.2., the roof
deck assembly shall meet the conditions of acceptance of CAN/ULC-S126, “Standard Method of Test for Fire Spread
Under Roof-Deck Assemblies.”
(2) Supports for the roof deck assembly referred to in Sentence (1) shall consist of
(a) fire-retardant-treated wood,
(b) heavy timber construction,
(c) noncombustible construction, or
(d) a combination thereof.
3.1.14.2.Metal Roof Deck Assemblies permalink →
(1) Except as permitted by Sentence (2), a metal roof deck assembly shall meet the conditions of acceptance of
CAN/ULC-S126, “Standard Method of Test for Fire Spread Under Roof-Deck Assemblies,” if
(a) it supports a combustible material above the deck that could propagate a fire beneath the roof deck assembly, and
(b) the deck is used to comply with the requirements of Sentences 3.2.2.25.(2), 3.2.2.32.(2), 3.2.2.62.(2), 3.2.2.68.(2),
3.2.2.78.(2) and 3.2.2.85.(2) for noncombustible construction.
(2) The requirements of Sentence (1) are waived provided
(a) the combustible material above the roof deck is protected by not less than 12.7 mm thick gypsum board,
mechanically fastened to a supporting assembly if located beneath the roof deck, or by a thermal barrier conforming
to one of Clauses 3.1.5.15.(2)(c) to (e) that is located
(i) on the underside of the combustible material, or
(ii) beneath the roof deck,
(b) the building is sprinklered throughout, or
(c) the roof assembly has a fire-resistance rating not less than 45 min.
3.1.15.Roof Covering
3.1.15.1.Roof Covering Classification permalink →
(1) A roof covering classification shall be determined in conformance with CAN/ULC-S107, “Standard Method of Fire
Tests of Roof Coverings.” (See Note A-3.1.15.1.(1))
3.1.15.2.Roof Coverings permalink →
(1) Except as provided by Sentences (2) to (4), every roof covering shall have a Class A, B or C classification as
determined in accordance with Article 3.1.15.1.
(2) A roof covering is not required to have a Class A, B or C classification for
(a) a tent,
(b) an air-supported structure,
(c) a building of Group A, Division 2 occupancy not more than 2 storeys in building height and not more than 1 000 m2
in building area, provided the roof covering is underlaid with noncombustible material, or
(d) a steel building system described in Article 4.3.4.3., provided the roof covering consists of brick, masonry, concrete,
metal sheets or metal shingles.
(3) Except as provided in Sentence (5), roof coverings on buildings conforming to Article 3.2.2.51. or 3.2.2.60. shall
have a Class A classification where the roof height is greater than 25 m measured from the floor of the first storey to the
highest point of the roof.
(4) Except as provided in Sentence (5), roof coverings in buildings or parts of buildings permitted to be of encapsulated
mass timber construction shall have a Class A classification if the roof height is greater than 25 m measured from the
floor of the first storey to the highest point of the roof.
r1 (5) Where buildings or parts thereof conforming to Article 3.2.2.48., 3.2.2.51., 3.2.2.57., 3.2.2.60. or 3.2.2.93. include
non-contiguous roof assemblies at different elevations, the roof coverings referred to in Sentences (3) and (4) are
permitted to be evaluated separately to determine the roof covering classification required.
3.1.16.Fabrics
3.1.16.1.Fabric Awnings, Canopies and Marquees permalink →
(1) Fabrics used as part of an awning, canopy or marquee that is located within or attached to a building of any type of
construction shall conform to CAN/ULC-S109, “Standard Method of Flame Tests of Flame-Resistant Fabrics and Films.”
3.1.17.Occupant Load
3.1.17.1.Occupant Load Determination permalink →
(1) The occupant load of a floor area or part of a floor area, shall be based on
(a) the number of seats in an assembly occupancy having fixed seats,
(b) 2 persons per sleeping room in a dwelling unit, or
(c) the number of persons for which the area is designed, but not less than that determined from Table 3.1.17.1. for
occupancies other than those described in Clauses (a) and (b), unless it can be shown that the area will be occupied
by fewer persons.
(2) If a floor area or part thereof it has been designed for an occupant load other than that determined from Table
3.1.17.1., a permanent sign indicating that occupant load shall be posted in a conspicuous location.
(3) For the purposes of this Article, mezzanines, tiers and balconies shall be regarded as part of the floor area.
(4) If a room or group of rooms is intended for different occupancies at different times, the value to be used from Table
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.17.1.shall be the value that gives the greatest number of persons for the occupancies concerned. permalink →
Table 3.1.17.1.
Occupant Load
Forming Part of Article 3.1.17.1.
Type of Use of Floor Area or Part Thereof Area per Person, m2
Assembly uses
space with fixed seats (1)
space with non-fixed seats 0.75
stages for theatrical performances 0.75
space with non-fixed seats and tables 0.95
standing space 0.40
stadia and grandstands 0.60
bowling alleys, pool and billiard rooms 9.30
classrooms 1.85
school shops and vocational rooms 9.30
reading or writing rooms or lounges 1.85
dining, beverage and cafeteria space 1.20
laboratories in schools 4.60
Care, care and treatment or detention uses
B-1 : detention quarters 11.60
B-2 : treatment and sleeping areas 10.00
B-3 : sleeping room areas 10.00
(See also Article 3.7.1.3.)
Residential uses
dwelling units (2)
dormitories 4.60
Business and personal services uses
personal service shops 4.60
offices 9.30
Mercantile uses
basements and first storeys 3.70
second storeys having a principal entrance from a pedestrian thoroughfare or a parking area 3.70
other storeys 5.60
Industrial uses
manufacturing or process rooms 4.60
storage garages 46.00
storage spaces (warehouse) 28.00
aircraft hangars 46.00
Other uses
cleaning and repair goods 4.60
kitchens 9.30
storage 46.00
public corridors intended for occupancies in addition to pedestrian travel 3.70(3)
Notes to Table 3.1.17.1.:
(1) See Clause 3.1.17.1.(1)(a).
(2) See Clause 3.1.17.1.(1)(b)
(3) See Note A-3.3.
This provision includes a table — formatting is preserved from the source; refer to the official code for the authoritative layout.
3.1.17.2.Public Pools permalink →
(1) The occupant load of a public pool, except a wave action pool, shall be determined by the following formula:
occupant load = D + S
2.5 1.4
where,
D = the water surface area in square metres of the part of the pool that is deeper than 1 350 mm; and
S = the water surface area in square metres of the part of the pool that is 1 350 mm in depth or less.
(2) The occupant load of a wave action pool shall be determined by the following formula:
occupant load = D + S
2.5 1.1
where,
D = the water surface area in square metres of the part of the pool where the still water depth is greater than
1 000 mm; and
S = the water surface area in square metres of the part of the pool where the still water depth is 1 000 mm or
less.
3.1.18.Reserved
3.1.19.Drainage and Grades
3.1.19.1.Drainage permalink →
(1) The building shall be located and the building site graded so that water will not accumulate at or near the building
and will not adversely affect any adjacent properties.
3.1.20.Above Ground Electrical Conductors
3.1.20.1.Clearance to Buildings permalink →
(1) A building shall not be located beneath existing above ground electrical conductors.
(2) The horizontal clearance measured from the maximum conductor swing to the building, including balconies, fire
escapes, flat roofs or other accessible projections beyond the face of the building, shall,
(a) be not less than 1 m, for electrical conductors carrying voltages 750 V or less, except where necessary to connect to
the electrical wiring of the building,
(b) be not less than 3 m, for electrical conductors carrying voltages greater than 750 V but not exceeding 46 kV,
(c) be not less than 3.7 m, for electrical conductors carrying voltages greater than 46 kV but not exceeding 69 kV, or
(d) conform to the requirements of CAN/CSA-C22.3 No.1, “Overhead Systems,” for electrical conductors carrying
voltages greater than 69 kV.
(3) Where the swing of an above ground electrical conductor not owned or operated by an electrical supply authority is
not known, a swing of not less than 1.8 m shall be used.
(4) Sentences (1) to (3) do not apply to a building containing electrical equipment and electrical installations used
exclusively in the generation, transformation or transmission of electrical power or energy intended for sale or distribution
to the public.
3.1.21.Glass in Guards
3.1.21.1.Glass permalink →
(1) Except as provided in Sentence 3.3.4.7.(2), glass in guards shall conform to MMAH Supplementary Standard
SB-13, “Glass in Guards.”
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Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.