Fire protection and sound transmission (Part 9) (Small Buildings)

Last updated October 22, 2026

Values this chapter turns on

rating for floors, other than over crawl spaces: 45 min; rating for floors, other than over crawl spaces
closure rating in a 45 min fire separation: 20 min; closure rating in a 45 min fire separation
total occupant load requiring a fire alarm: over 300; total occupant load requiring a fire alarm
dwelling unit separating assembly, minimum: STC 50; dwelling unit separating assembly, minimum

Section 9.10 is where the Small Buildings exam goes well past the House exam. A small apartment building, office, store or workshop needs suite separations, separations between major occupancies, rated service rooms, closures and sometimes a fire alarm system. Section 9.11 adds sound control. First ask: what occupancy, and how many suites?

Classification, building size, ratings and construction types

Every Part 9 building, or part of one, is classified by major occupancy into Group C (residential), D (business and personal services), E (mercantile), F2 (medium-hazard industrial) or F3 (low-hazard industrial) (OBC Div. B 9.10.2.1., Table 9.10.2.1.). Groups A, B and F1, and retirement homes, are outside Part 9 (OBC Div. A 1.3.3.3.), and some uses are sent to Part 3 even inside a Part 9 building: assembly rooms, rooms for hazardous materials, and basements with more than 1 storey or over 600 m² (OBC Div. B 9.10.1.3.).

The F2 and F3 split is set by fire load. Low-hazard industrial has a combustible content of not more than 50 kg/m² or 1,200 MJ/m² of floor area; above that it is medium-hazard (OBC Div. A 1.4.1.2., OBC Div. A 1.4.1.2.).

Floor and roof ratings come from Table 9.10.8.1.. Read it by occupancy row (residential, or all others) and building height in storeys, then pick the column for floors, mezzanine floors or roofs. The value to remember: floors (other than floors over crawl spaces) need 45 min in every Part 9 row. Mezzanine and roof ratings differ from row to row (some cells show N/A), so check the row before answering.

Loadbearing walls, columns and arches in the storey below carry at least the rating of the floor or roof they support (OBC Div. B 9.10.8.3.). The table does not apply to a dwelling unit with no other dwelling unit above or below it, or to one that is not above or below another major occupancy (OBC Div. B 9.10.8.10.).

Where one major occupancy sits entirely above another, each portion is rated as if the whole building were that occupancy (OBC Div. B 9.10.2.3.). A minor occupancy that totals not more than 10% of the floor area on its storey can be ignored for this purpose, unless it is F2 (OBC Div. B 9.10.2.4.).

Practice this topic

Fire separations, service rooms and closures

A fire separation must be a continuous barrier (OBC Div. B 9.10.9.2.) with closures in its openings (OBC Div. B 9.10.9.3.). Floors are generally fire separations, except inside a dwelling unit or where Table 9.10.8.1 asks for no rating (OBC Div. B 9.10.9.4.).

Separation	Minimum rating	Source
Residential from other occupancies (general)	1 h	9.10.9.13.
Residential from mercantile or F2	2 h (1 h if not more than 2 dwelling units over a store)	9.10.9.13.
Suite to suite (not Group D)	45 min	9.10.9.15.
Residential suites	45 min; 1 h for a dwelling unit of 2 or more storeys	9.10.9.16.
Public corridor	45 min	9.10.9.17.
Storage garage	1.5 h; 1 h for 5 vehicles or fewer	9.10.9.18.
Repair garage	2 h; 1 h in some one-storey cases	9.10.9.19.
Service room, unsprinklered floor area	1 h	9.10.10.3.
Incinerator room	2 h	9.10.10.5.

Business and personal services suites are not in the 45 min suite rule, and in a sprinklered building Group D and E suites served by a qualifying public corridor need no separation from each other (OBC Div. B 9.10.9.15.). The repair garage drops to 1 h only when the building is one storey, run as a single suite, and the only other occupancy is mercantile (OBC Div. B 9.10.9.19.). Fuel-fired appliances normally go in a 1 h service room, but not when they serve only one room or suite, or a building of not more than 400 m² building area and 2 storeys (OBC Div. B 9.10.10.4.).

Closures are rated less than the wall they sit in. Read Table 9.10.13.1. like this: a 45 min wall needs a 20 min closure, a 1 h wall a 45 min closure, a 2 h wall a 1.5 h closure. An opening in an interior fire separation is capped at 11 m² with no dimension over 3.7 m if either side is unsprinklered, or 22 m² and 6 m if both sides are sprinklered (OBC Div. B 9.10.13.8.).

Practice this topic

Firewalls and spatial separation

A party wall on a property line must be a firewall built to Part 3 (OBC Div. B 9.10.11.1., OBC Div. B 9.10.11.3.). The exception is residential: between side-by-side dwelling units with none stacked above another, a 1 h fire separation running from the top of the footings to the underside of the roof deck will do (OBC Div. B 9.10.11.2.).

The exposing building face is the part of an exterior wall facing one direction, up to the ceiling of the top storey, or of one fire compartment (OBC Div. A 1.4.1.2.). The limiting distance is measured at right angles from that face to the property line, the centre line of a street, lane or public thoroughfare, or an imaginary line between buildings or fire compartments on the same property (OBC Div. A 1.4.1.2.).

Subsection 9.10.14 covers all Part 9 buildings except those with only dwelling units and none stacked, and houses with a secondary suite, which use 9.10.15 (OBC Div. B 9.10.14.1., OBC Div. B 9.10.15.1.). The maximum aggregate area of unprotected openings can be found three ways: from Table 9.10.14.4., from Subsection 3.2.3, or, where the limiting distance is at least 1.2 m, by a formula: the limiting distance squared for Groups C, D and F3, or half of it for Groups E and F2 (OBC Div. B 9.10.14.4.). The table has two parts; mercantile and medium-hazard industrial buildings use the second, stricter part.

Worked exampleUnprotected openings

An unsprinklered one-storey office (Group D) has an exposing building face of 100 m² and a limiting distance of 3 m. In the first part of the table, the 100 m² row under 3 m gives 13%, so 13 m² of openings are allowed. The formula gives 3 squared, or 9 m², so the table is better here. If the same wall belonged to a store (Group E), the second part of the table gives 6%, only 6 m². Doubling is allowed with wired glass or glass block, or when the building and all rooms behind the openings are sprinklered. Openings of 130 cm² or less are not counted (OBC Div. B 9.10.14.6.).

Construction of the face comes from Table 9.10.14.5.. Find your occupancy group, then the band for the percentage of unprotected openings permitted. For Groups C, D and F3 the ratings are 1 h or 45 min; for Groups E and F2 they are 2 h or 1 h. At 10% or less, construction and cladding must be noncombustible. Where there is no fire department, or one not organized, trained and equipped for the community's needs, the limiting distance used in the sentences listed in OBC Div. B 9.10.14.3A. is doubled for an unsprinklered building.

Practice this topic

Fire blocks and flame spread

Concealed spaces in walls need fire blocks at each floor level and at intervals of not more than 20 m horizontally and 3 m vertically, unless the space is filled with insulation, is a single air space not over 25 mm thick in an insulated wall, or its exposed materials are noncombustible or have a flame-spread rating of 25 or less (OBC Div. B 9.10.16.2.).

Interior walls and ceilings are limited to a surface flame-spread rating of 150, doors to 200 (OBC Div. B 9.10.17.1.). Exits are stricter: at least 90% of wall and ceiling surfaces at 25 or less (OBC Div. B 9.10.17.2., OBC Div. B 9.10.17.3.). Unsprinklered public corridor walls need 90% at 75 or less, or 90% of the upper half at 25 or less (OBC Div. B 9.10.17.5.).

Practice this topic

Fire alarm systems, smoke alarms and firefighting

A fire alarm system is required when the building has more than 3 storeys including storeys below the first, when the total occupant load exceeds 300, or when the load for an occupancy in Table 9.10.18.2. is exceeded (OBC Div. B 9.10.18.2.). Read that table by major occupancy. For Groups D and E the trigger is an occupant load of more than 150 above or below the first storey; the residential row is based on persons with sleeping accommodation, and the industrial row is stricter than D and E. A residential building is exempt when an exit or public corridor serves not more than 4 suites, or each suite has direct access to an exterior exit facility.

Smoke alarms go in every dwelling unit and every sleeping room not in a dwelling unit (OBC Div. B 9.10.19.1.), hard-wired with battery backup (OBC Div. B 9.10.19.4.).

Unsprinklered second and third storeys need a window or access panel at least 1,100 mm high and 550 mm wide with a sill not over 900 mm, in a wall facing a street (OBC Div. B 9.10.20.1.).

Practice this topic

Sound transmission

A dwelling unit, or a hotel suite, must be separated from other spaces where noise may be generated by either an assembly and flanking construction with an ASTC of at least 47, or a separating assembly of at least STC 50 with adjoining construction built to Article 9.11.1.4. Next to an elevator shaft or refuse chute the minimum is STC 55 (OBC Div. B 9.11.1.1.).

Practice this topic

Common traps

Using the first part of Table 9.10.14.4 for a store. Mercantile and F2 use the second part.
Applying the 1 h residential to mercantile rating when there are 3 or more dwelling units. That case needs 2 h.
Giving the closure the same rating as the wall. Closures are one step lower.
Forgetting that Group D suites have no 45 min suite-to-suite rule.

Chapter review

Chapter at a glance

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

Chapter at a glance: the key idea in each section
Section	Key idea
Classification, building size, ratings and construction types	Every Part 9 building, or part of one, is classified by major occupancy into Group C (residential), D (business and personal services), E (mercantile), F2 (medium-hazard…
Fire separations, service rooms and closures	A fire separation must be a continuous barrier with closures in its openings.
Firewalls and spatial separation	A party wall on a property line must be a firewall built to Part 3. The exception is residential: between side-by-side dwelling units with none stacked above another, a 1 h fire…
Fire blocks and flame spread	Concealed spaces in walls need fire blocks at each floor level and at intervals of not more than 20 m horizontally and 3 m vertically, unless the space is filled with insulation…
Fire alarm systems, smoke alarms and firefighting	A fire alarm system is required when the building has more than 3 storeys including storeys below the first, when the total occupant load exceeds 300, or when the load for an…
Sound transmission	A dwelling unit, or a hotel suite, must be separated from other spaces where noise may be generated by either an assembly and flanking construction with an ASTC of at least 47, or…

Classification, building size, ratings and construction types
Every Part 9 building, or part of one, is classified by major occupancy into Group C (residential), D (business and personal services), E (mercantile), F2 (medium-hazard…
Fire separations, service rooms and closures
A fire separation must be a continuous barrier with closures in its openings.
Firewalls and spatial separation
A party wall on a property line must be a firewall built to Part 3. The exception is residential: between side-by-side dwelling units with none stacked above another, a 1 h fire…
Fire blocks and flame spread
Concealed spaces in walls need fire blocks at each floor level and at intervals of not more than 20 m horizontally and 3 m vertically, unless the space is filled with insulation…
Fire alarm systems, smoke alarms and firefighting
A fire alarm system is required when the building has more than 3 storeys including storeys below the first, when the total occupant load exceeds 300, or when the load for an…
Sound transmission
A dwelling unit, or a hotel suite, must be separated from other spaces where noise may be generated by either an assembly and flanking construction with an ASTC of at least 47, or…

Usual exam traps

Using the first part of Table 9.10.14.4 for a store. Mercantile and F2 use the second part.
Applying the 1 h residential to mercantile rating when there are 3 or more dwelling units. That case needs 2 h.
Giving the closure the same rating as the wall. Closures are one step lower.
Forgetting that Group D suites have no 45 min suite-to-suite rule.

Practice this chapter

Questions on Fire protection and sound transmission (Part 9), in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.

Practice this chapter Small Buildings calculations

Code cited in this chapter

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

OBC Div. B 9.10.2.1. Occupancy Classification
(1)Every building or part of it shall be classified according to its major occupancy as belonging to one of the groups or divisions described in Table 9.10.2.1.
Open OBC Div. B 9.10.2.1. in the code viewer
OBC Div. B Table 9.10.2.1. Occupancy Classifications — Forming Part of Sentence 9.10.2.1.(1)
Table 9.10.2.1 — Occupancy Classifications — Forming Part of Sentence 9.10.2.1.(1) Group | Division | Description of Major Occupancies[1] C | N/A | Residential occupancies D | N/A | Business and personal services occupancies E | N/A | Mercantile occupancies F | 2 | Medium-hazard industrial occupancies F | 3 | Low-hazard industrial occupancies (Does not include storage garages serving houses or individual dwelling units) Notes to Table 9.10.2.1.: (1) See Note A-3.1.2.1.(1).
Open OBC Div. B Table 9.10.2.1. in the code viewer
OBC Div. A 1.3.3.3. Application of Part 9
(1)Subject to Article 1.3.3.3B., Part 9 of Division B applies to all buildings described in Article 1.1.1.1. of 3 storeys or less in building height, having a building area not exceeding 600 m², and used for major occupancies classified as
(a)reserved
(b)Group C, residential occupancies other than buildings used for retirement homes, (See Note A-9.1.1.1.(1) of Division B)
(c)Group D, business and personal services occupancies,
(d)Group E, mercantile occupancies, or
(e)Group F, Divisions 2 and 3, medium- and low-hazard industrial occupancies.
Open OBC Div. A 1.3.3.3. in the code viewer
OBC Div. B 9.10.1.3. Items Under Part 3 Jurisdiction
(1)Tents, air-supported structures, transformer vaults, walkways, elevators and escalators shall conform to Part 3.
(2)Where rooms or spaces are intended for an assembly occupancy, such rooms or spaces shall conform to Part 3.
(3)Basements containing more than 1 storey or exceeding 600 m² in area shall conform to Part 3.
(4)Where rooms or spaces are intended for the storage, manufacture or use of hazardous or explosive material, such rooms or spaces shall conform to Part 3.
(5)Reserved.
(6)Openings through floors that are not protected by shafts or closures shall be protected in conformance with Subsection 3.2.8. (See also Sentence 9.9.4.7.(1))
(7)Chutes and shafts shall conform to Subsection 3.6.3. except where they are entirely contained within a dwelling unit.
(8)Sprinkler systems shall be designed, constructed and installed in conformance with Articles 3.2.5.12. to 3.2.5.15. and 3.2.5.17. (See Note A-9.10.1.3.(8) and (9))
(9)Standpipe and hose systems shall be designed, constructed and installed in conformance with Articles 3.2.5.8. to 3.2.5.11. and 3.2.5.17. (See Note A-9.10.1.3.(8) and (9))
(10)Fire pumps shall be installed in conformance with Articles 3.2.5.17. and 3.2.5.18.
(11)Where fuel-fired appliances are installed on a roof, such appliances shall be installed in conformance with Article 3.6.1.5.
Open OBC Div. B 9.10.1.3. in the code viewer
OBC Div. A 1.4.1.2.(1) Low-hazard industrial occupancy (Group F, Division 3)
Low-hazard industrial occupancy (Group F, Division 3) means an industrial occupancy in which the combustible content is not more than 50 kg/m² or 1,200 MJ/m² of floor area.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. A 1.4.1.2.(1) Medium-hazard industrial occupancy (Group F, Division 2)
Medium-hazard industrial occupancy (Group F, Division 2) means an industrial occupancy in which the combustible content is more than 50 kg/m² or 1,200 MJ/m² of floor areaand not classified as a high-hazard industrial occupancy.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. B Table 9.10.8.1. Fire Resistance Ratings for Floors and Roofs — Forming Part of Sentence 9.10.8.1.(1)
Table 9.10.8.1 — Fire Resistance Ratings for Floors and Roofs — Forming Part of Sentence 9.10.8.1.(1) Major Occupancy | Maximum Building Height, Storeys | Minimum Fire-Resistance Rating for Floors Except Floors over Crawl Spaces, min | Minimum Fire-Resistance Rating for Mezzanine Floors, min | Minimum Fire-Resistance Rating for Roofs, min Residential (Group C) | 3 | 45 | 45 | N/A All other occupancies | 2 | 45 | N/A | N/A All other occupancies | 3 | 45 | 45 | 45
Open OBC Div. B Table 9.10.8.1. in the code viewer
OBC Div. B 9.10.8.3. Fire-Resistance Ratings for Walls, Columns and Arches
(1)Except as otherwise provided in this Subsection, all loadbearing walls, columns and arches in the storey immediately below a floor or roof assembly shall have a fire-resistance rating of not less than that required for the supported floor or roof assembly.
(2)Light-frame walls, columns, arches and beams as well as loadbearing steel elements that support floors between dwelling units in a house with a secondary suite including their common spaces shall be protected by not less than 15.9 mm thick Type-X gypsum board. (See Note A-9.10.8.3.(2))
Open OBC Div. B 9.10.8.3. in the code viewer

Show all 48 articles

OBC Div. B 9.10.8.10. Non-Application to Houses
(1)Table 9.10.8.1. does not apply to
(a)a dwelling unit that has no other dwelling unit above or below it,
(b)houses with a secondary suite, where the floor framing is protected on the underside by a continuous smoke-tight barrier of not less than 15.9 mm thick Type X gypsum board, or
(c)a dwelling unit that is not above or below another major occupancy.
Open OBC Div. B 9.10.8.10. in the code viewer
OBC Div. B 9.10.2.3. Major Occupancies Above Other Major Occupancies
(1)Except as permitted in Article 9.10.2.4., in any building containing more than one major occupancy in which one major occupancy is located entirely above another, the requirements of Article 9.10.8.1. for each portion of the building containing a major occupancy shall be applied to that portion as if the entire building was of that major occupancy.
Open OBC Div. B 9.10.2.3. in the code viewer
OBC Div. B 9.10.2.4. Buildings Containing More Than One Major Occupancy
(1)In a building containing more than one major occupancy, where the aggregate area of all major occupancies in a particular group or division does not exceed 10% of the floor area on the storey on which they are located, they need not be considered as major occupancies for the purposes of Articles 9.10.2.3. and 9.10.8.1. provided they are not classified as Group F, Division 2 occupancies.
Open OBC Div. B 9.10.2.4. in the code viewer
OBC Div. B 9.10.9.2. Continuous Barrier
(1)Except as permitted in Article 9.10.9.3., a wall or floor assembly required to be a fire separation shall be constructed as a continuous barrier against the spread of fire and retard the passage of smoke.
(2)Except as permitted in Article 9.10.9.3., a wall or floor assembly required to be a smoke-tight barrier shall be constructed as a continuous barrier against the spread of smoke. (See Note A-9.10.9.2.(2) and (3))
(3)Except as provided in Sentence (6), the continuity of a fire separation where it abuts another fire separation or smoke-tight barrier, a floor, a ceiling, or a roof shall be maintained 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 abutting fire separation. (See Note A-9.10.9.2.(2) and (3)) (See also Note A-3.1.8.3.(2))
(4)Except as provided in Sentence (6), 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 for the horizontal fire separation.
(5)Except as provided in Sentence (6), all gypsum board joints in the assemblies described in Sentences (1) and (2) shall conform to CSA A82.31-M, "Gypsum Board Application," to maintain the integrity of the smoke-tight barrier over the entire surface.
(6)Joints between ceilings and walls, between floors and walls, and between walls at corners need not comply with Sentences (3) to (5) 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.
Open OBC Div. B 9.10.9.2. in the code viewer
OBC Div. B 9.10.9.3. Openings to be Protected With Closures
(1)Except as permitted in Articles 9.10.9.5. to 9.10.9.8., openings in required fire separations shall be protected with closures conforming to Subsection 9.10.13.
Open OBC Div. B 9.10.9.3. in the code viewer
OBC Div. B 9.10.9.4. Floor Assemblies
(1)Except as permitted in Sentences (2) to (4), all floor assemblies shall be constructed as fire separations.
(2)Floor assemblies contained within dwelling units and within houses with a secondary suite need not be constructed as fire separations.
(3)Floor assemblies for which no fire-resistance rating is required by Subsection 9.10.8. and floors of mezzanines not required to be counted as storeys in Articles 9.10.4.1. and 9.10.4.2. need not be constructed as fire separations.
(4)Where a crawl space is not required by Article 9.10.8.9. to be constructed as a basement, the floor above it need not be constructed as a fire separation.
Open OBC Div. B 9.10.9.4. in the code viewer
OBC Div. B 9.10.9.13. Separation of Residential Occupancies
(1)Except as provided in Sentences (2) and (4), residential occupancies shall be separated from all other major occupancies by a fire separation having a fire-resistance rating of not less than 1 h.
(2)Except as provided in Sentence (3), a major occupancy classified as a residential occupancy, including live/work units, shall be separated from other major occupancies classified as mercantile or medium hazard industrial occupancies by a fire separation having a fire-resistance rating of not less than 2 h.
(3)Where not more than two dwelling units or live/work units are located in a building containing a mercantile occupancy, such mercantile occupancy shall be separated from the dwelling units or live/work units by a fire separation having not less than 1 h fire-resistance rating.
(4)The requirement for fire separations between major occupancies in Sentence (1) is waived for the occupancies allowed within live/work units.
Open OBC Div. B 9.10.9.13. in the code viewer
OBC Div. B 9.10.9.15. Separation of Suites
(1)Except as required in Article 9.10.9.16. and as permitted by Sentence (2), each suite in other than business and personal services occupancies shall be separated from adjoining suites by a fire separation having a fire-resistance rating of not less than 45 min.
(2)In sprinklered buildings, suites of business and personal services occupancy and mercantile occupancy that are served by public corridors conforming with Clause 3.3.1.4.(4)(b) are not required to be separated from each other by fire separations.
Open OBC Div. B 9.10.9.15. in the code viewer
OBC Div. B 9.10.9.16. Separation of Residential Suites
(1)Except as provided in Sentences (2) and (3) and Article 9.10.21.2., suites in residential occupancies shall be separated from adjacent rooms and suites by a fire separation having a fire-resistance rating of not less than 45 min.
(2)Sleeping rooms in boarding, lodging or rooming houses where sleeping accommodation is provided for not more than 8 boarders or lodgers need not be separated from the remainder of the floor area as required in Sentence (1) where the sleeping rooms form part of the proprietor's residence and do not contain cooking facilities.
(3)Except as provided in Sentences (4) and (5), dwelling units that contain 2 or more storeys including basements shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 1 h. (See Note A-3.3.4.4.(1))
(4)Walls and floor-ceiling framing in a house with a secondary suite that separate dwelling units from each other or dwelling units from ancillary spaces and common spaces need not comply with Sentence (1), where the walls and floor-ceiling framing are protected by a continuous smoke-tight barrier of not less than 15.9 mm thick Type X gypsum board installed on
(a)both sides of walls, and
(b)the underside of floor-ceiling framing.
(5)The fire-resistance rating of the fire separation required in Sentence (4) is permitted to be waived where the house with a secondary suite is sprinklered.
Open OBC Div. B 9.10.9.16. in the code viewer
OBC Div. B 9.10.9.17. Separation of Public Corridors
(1)Except as otherwise required by this Part and as provided in Sentences (2) to (5), public corridors shall be separated from the remainder of the building by a fire separation having not less than a 45 min fire-resistance rating.
(2)In other than residential occupancies, no fire-resistance rating is required for fire separations between a public corridor and the remainder of the building if
(a)the floor area is sprinklered,
(b)the sprinkler system is electrically supervised in conformance with Sentence 3.2.4.9.(3), and
(c)the operation of the sprinkler system will cause a signal to be transmitted to the fire department in conformance with Sentence 3.2.4.7.(4).
(3)In other than residential occupancies, no fire separation is required between a public corridor and the remainder of the building if
(a)the floor area is sprinklered,
(b)the sprinkler system is electrically supervised in conformance with Sentence 3.2.4.9.(3),
(c)the operation of the sprinkler system will cause a signal to be transmitted to the fire department in conformance with Sentence 3.2.4.7.(4), and
(d)the corridor exceeds 5 m in width.
(4)Where a public corridor is located in a house with a secondary suite, a continuous smoke-tight barrier of not less than 15.9 mm thick Type X gypsum board shall be installed on
(a)both sides of walls separating the corridor from the remainder of the building, and
(b)the underside of floor-ceiling framing separating the corridor from the remainder of the building.
(5)No fire separation is required in a sprinklered floor area between a public corridor and a space containing plumbing fixtures required by Article 3.7.4.2. and Section 9.31., provided
(a)the space and the public corridor are separated from the remainder of the storey by a fire separation having a fire-resistance rating not less than that required between the public corridor and the remainder of the storey, and
(b)the plumbing fixtures are not located within a dwelling unit or suite.
Open OBC Div. B 9.10.9.17. in the code viewer
OBC Div. B 9.10.9.18. Separation of Storage Garages
(1)Except as provided in Sentences (2) and (3), a storage garage shall be separated from other occupancies by a fire separation having not less than a 1.5 h fire-resistance rating.
(2)Except as permitted in Sentence (3), storage garages containing 5 motor vehicles or fewer shall be separated from other occupancies by a fire separation of not less than 1 h.
(3)Where a storage garage serves only the dwelling unit to which it is attached or in which it is built, it shall be considered as part of that dwelling unit and the fire separation required in Sentence (2) need not be provided between the garage and the dwelling unit.
(4)Except as provided in Sentence (5), where a storage garage is attached to or built into a building of residential occupancy
(a)an air barrier system conforming to Subsection 9.25.3. shall be installed between the garage and the remainder of the building to provide an effective barrier to gas and exhaust fumes, and
(b)every door between the garage and the remainder of the building shall conform to Article 9.10.13.15. (See Note A-9.10.9.18.(4))
(5)Where membrane materials are used to provide the required airtightness in the air barrier system, all joints shall be sealed and structurally supported.
Open OBC Div. B 9.10.9.18. in the code viewer
OBC Div. B 9.10.9.19. Separation of Repair Garages
(1)Except as provided in Sentences (2) and (3), a repair garage shall be separated from other occupancies by a fire separation having a fire-resistance rating of not less than 2 h.
(2)Ancillary spaces directly serving a repair garage, including waiting rooms, reception rooms, tool and parts storage areas and supervisory office space, need not be separated from the repair garage but shall be separated from other occupancies as required in Sentence (1).
(3)The fire separation referred to in Sentence (1) shall have a fire-resistance rating of not less than 1 h, where
(a)the building is not more than one storey in building height,
(b)the building is operated as a single suite, and
(c)the only occupancy other than the repair garage is a mercantile occupancy.
(4)Except as provided in Sentence (5), where a building containing a repair garage also contains a dwelling unit, an air barrier system conforming to Subsection 9.25.3. shall be installed between the dwelling unit and the suite containing the garage to provide an effective barrier to gas and exhaust fumes. (See Note A-9.10.9.18.(4))
(5)Where membrane materials are used to provide the required airtightness in the air barrier system, all joints shall be sealed and structurally supported.
Open OBC Div. B 9.10.9.19. in the code viewer
OBC Div. B 9.10.10.3. Separation of Service Rooms
(1)Except as provided in Sentence (2) and Articles 9.10.10.5. and 9.10.10.6., service rooms shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 1 h when the floor area containing the service room is not sprinklered.
(2)Where a room contains a limited quantity of service equipment and the service equipment does not constitute a fire hazard, the requirements in Sentence (1) shall not apply.
Open OBC Div. B 9.10.10.3. in the code viewer
OBC Div. B 9.10.10.5. Incinerators
(1)Service rooms containing incinerators shall be separated from the remainder of the building by a fire separation having a fire-resistance rating of not less than 2 h.
(2)The design, construction, installation and alteration of each indoor incinerator shall conform to NFPA 82, "Standard on Incinerators and Waste and Linen Handling Systems and Equipment."
(3)Every incinerator shall be connected to a chimney flue conforming to the requirements in Section 9.21. and serving no other appliance.
(4)An incinerator shall not be located in a room with other fuel-fired appliances.
Open OBC Div. B 9.10.10.5. in the code viewer
OBC Div. B 9.10.10.4. Locations of Fuel-Fired Appliances
(1)Except as provided in Sentences (2) and (3) and Article 9.10.10.5., fuel-fired appliances shall be located in a service room separated from the remainder of the building by a fire separation having not less than a 1 h fire-resistance rating.
(2)Except as required in the appliance installation standards referenced in Sentences 6.2.1.5.(1) and 9.10.10.5.(1), fuel-fired space-heating appliances, space-cooling appliances and service water heaters need not be separated from the remainder of the building as required in Sentence (1),
(a)where the appliances serve
(i)not more than one room or suite, or
(ii)a building with a building area of not more than 400 m² and a building height of not more than 2 storeys, or
(b)where the appliances
(i)serve a house with a secondary suite including their common spaces, and
(ii)are located in a service room where both sides of any wall assemblies and the underside of any floor-ceiling framing separating this room from both dwelling units or their common spaces are protected by a continuous smoke-tight barrier consisting of not less than 15.9 mm thick Type X gypsum board.
(3)Sentence (1) does not apply to fireplaces and cooking appliances.
Open OBC Div. B 9.10.10.4. in the code viewer
OBC Div. B Table 9.10.13.1. Fire-Protection Ratings for Closures — Forming Part of Sentence 9.10.13.1.(1)
Table 9.10.13.1 — Fire-Protection Ratings for Closures — Forming Part of Sentence 9.10.13.1.(1) Forming Part of Sentence 9.10.13.1.(1) Required Fire-Resistance Rating of Fire Separation | Required Fire-Protection Rating of Closure 30 or 45 min | 20 min[1] 1 h | 45 min[1] 1.5 h | 1 h 2 h | 1.5 h 3 h | 2 h 4 h | 3 h Notes to Table 9.10.13.1.: (1) See Article 9.10.13.2.
Open OBC Div. B Table 9.10.13.1. in the code viewer
OBC Div. B 9.10.13.8. Maximum Size of Opening
(1)The size of an opening in an interior fire separation, even where protected with a closure, shall not exceed 11 m², with no dimension greater 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, even where protected with a closure, shall not exceed 22 m², with no dimension greater than 6 m, when the fire compartments on both sides of the fire separation are sprinklered.
Open OBC Div. B 9.10.13.8. in the code viewer
OBC Div. B 9.10.11.1. Required Firewalls
(1)Except as provided in Articles 9.10.11.2., a party wall on a property line shall be constructed as a firewall.
Open OBC Div. B 9.10.11.1. in the code viewer
OBC Div. B 9.10.11.3. Construction of Firewalls
(1)Where firewalls are used, the requirements in Part 3 shall apply.
Open OBC Div. B 9.10.11.3. in the code viewer
OBC Div. B 9.10.11.2. Firewalls Not Required
(1)A party wall on a property line of a building of residential occupancy need not be constructed as a firewall, provided it is constructed as a fire separation having not less than a 1 h fire-resistance rating, where the party wall separates
(a)two dwelling units where there is no dwelling unit above another dwelling unit,
(b)a dwelling unit and a house with a secondary suite including their common spaces, or
(c)two houses with a secondary suite including their common spaces.
(2)Reserved.
(3)The wall described in Sentence (1) shall provide continuous protection from the top of the footings to the underside of the roof deck.
(4)Any space between the top of the wall described in Sentence (1) and the roof deck shall be tightly filled with mineral wool or noncombustible material.
Open OBC Div. B 9.10.11.2. in the code viewer
OBC Div. A 1.4.1.2.(1) Exposing building face
Exposing building face means that part of the exterior wall of a building that faces one direction and is located between ground level and the ceiling of its top storey or, where a building is divided into fire compartments, the exterior wall of a fire compartment that faces one direction.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. A 1.4.1.2.(1) Limiting distance
Limiting distance means the distance from an exposing building face to a property line, the centre line of a street, lane or public thoroughfare, or to an imaginary line between 2 buildings or fire compartments on the same property, measured at right angles to the exposing building face.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. B 9.10.14.1. Application
(1)This Subsection applies to buildings other than those to which Subsection 9.10.15, applies.
(2)This Subsection does not apply to a house with a secondary suite.
Open OBC Div. B 9.10.14.1. in the code viewer
OBC Div. B 9.10.15.1. Application
(1)This Subsection applies to
(a)buildings that contain only dwelling units and have no dwelling unit above another dwelling unit, and
(b)houses with a secondary suite including their common spaces. (See Note A-9.10.15.1.(1))
Open OBC Div. B 9.10.15.1. in the code viewer
OBC Div. B Table 9.10.14.4. Residential, business and personal services, and low-hazard industrial
Table 9.10.14.4 — Residential, business and personal services, and low-hazard industrial Forming Part of Sentence 9.10.14.4.(1) Maximum Total Area of Exposing Building Face, m² | Limiting Distance, <1.2 m | Limiting Distance, 1.2 m | Limiting Distance, 1.5 m | Limiting Distance, 2 m | Limiting Distance, 2.5 m | Limiting Distance, 3 m | Limiting Distance, 4 m | Limiting Distance, 6 m | Limiting Distance, 8 m | Limiting Distance, 10 m | Limiting Distance, 12 m | Limiting Distance, 16 m | Limiting Distance, 20 m | Limiting Distance, 25 m 10 | 0% | 8% | 12% | 21% | 33% | 55% | 96% | 100% | 100% | 100% | 100% | 100% | 100% | 100% 15 | 0% | 8% | 10% | 17% | 25% | 37% | 67% | 100% | 100% | 100% | 100% | 100% | 100% | 100% 20 | 0% | 8% | 10% | 15% | 21% | 30% | 53% | 100% | 100% | 100% | 100% | 100% | 100% | 100% 25 | 0% | 8% | 9% | 13% | 19% | 26% | 45% | 100% | 100% | 100% | 100% | 100% | 100% | 100% 30 | 0% | 7% | 9% | 12% | 17% | 23% | 39% | 88% | 100% | 100% | 100% | 100% | 100% | 100% 40 | 0% | 7% | 8% | 11% | 15% | 20% | 32% | 69% | 100% | 100% | 100% | 100% | 100% | 100% 50 | 0% | 7% | 8% | 10% | 14% | 18% | 28% | 57% | 100% | 100% | 100% | 100% | 100% | 100% 100 | 0% | 7% | 8% | 9% | 11% | 13% | 18% | 34% | 56% | 84% | 100% | 100% | 100% | 100% Over 100 | 0% | 7% | 7% | 8% | 9% | 10% | 12% | 19% | 28% | 40% | 55% | 92% | 100% | 100% Table 9.10.14.4 (continued) — Mercantile and medium-hazard industrial Maximum Total Area of Exposing Building Face, m² | Limiting Distance, <1.2 m | Limiting Distance, 1.2 m | Limiting Distance, 1.5 m | Limiting Distance, 2 m | Limiting Distance, 2.5 m | Limiting Distance, 3 m | Limiting Distance, 4 m | Limiting Distance, 6 m | Limiting Distance, 8 m | Limiting Distance, 10 m | Limiting Distance, 12 m | Limiting Distance, 16 m | Limiting Distance, 20 m | Limiting Distance, 25 m 10 | 0% | 4% | 6% | 10% | 17% | 25% | 48% | 100% | 100% | 100% | 100% | 100% | 100% | 100% 15 | 0% | 4% | 5% | 8% | 13% | 18% | 34% | 82% | 100% | 100% | 100% | 100% | 100% | 100% 20 | 0% | 4% | 5% | 7% | 11% | 15% | 27% | 63% | 100% | 100% | 100% | 100% | 100% | 100% 25 | 0% | 4% | 5% | 7% | 9% | 13% | 22% | 51% | 94% | 100% | 100% | 100% | 100% | 100% 30 | 0% | 4% | 4% | 6% | 9% | 12% | 20% | 44% | 80% | 100% | 100% | 100% | 100% | 100% 40 | 0% | 4% | 4% | 6% | 8% | 10% | 16% | 34% | 61% | 97% | 100% | 100% | 100% | 100% 50 | 0% | 4% | 4% | 5% | 7% | 9% | 14% | 29% | 50% | 79% | 100% | 100% | 100% | 100% 100 | 0% | 4% | 4% | 4% | 5% | 6% | 9% | 17% | 28% | 42% | 60% | 100% | 100% | 100% Over 100 | 0% | 4% | 4% | 4% | 4% | 5% | 6% | 10% | 14% | 20% | 27% | 46% | 70% | 100%
Open OBC Div. B Table 9.10.14.4. in the code viewer
OBC Div. B 9.10.14.4. Openings in Exposing Building Face
(1)Except as provided in Sentences (6) to (10) and Sentence 9.10.14.6.(1), the maximum aggregate area of unprotected openings in an exposing building face shall
(a)conform to Table 9.10.14.4.,
(b)conform to Subsection 3.2.3., or
(c)where the limiting distance is not less than 1.2 m, be equal to or less than
(i)the limiting distance squared, for residential occupancies, business and personal services occupancies and low-hazard industrial occupancies, and
(ii)half the limiting distance squared, for mercantile occupancies and medium-hazard industrial occupancies.
(2)Except as provided in Sentence 9.10.14.6.(1), openings in a wall having a limiting distance of less than 1.2 m shall be protected by closures, of other than wired glass or glass block, whose fire protection rating is in conformance with the fire-resistance rating required for the wall.
(3)Reserved.
(4)Reserved.
(5)Reserved.
(6)The maximum aggregate area of unprotected openings is permitted to be up to twice the area determined according to Sentence (1), where the unprotected openings are glazed with
(a)wired glass in steel frames as described in Article 9.10.13.5., or
(b)glass blocks, as described in Article 9.10.13.7.
(7)Where the building is sprinklered, the maximum aggregate area of unprotected openings is permitted to be up to twice the area determined according to Sentence (1), provided all rooms, including closets and bathrooms, that are adjacent to the exposing building face and that have unprotected openings are sprinklered, notwithstanding any exemptions in the sprinkler standards referenced in Article 3.2.5.12.
(8)The maximum aggregate area of unprotected openings in an exposing building face of a storage garage need not comply with Sentence (1), where
(a)all storeys are constructed as open-air storeys, and
(b)the storage garage has a limiting distance of not less than 3 m.
(9)The maximum aggregate area of unprotected openings in an exposing building face of a storey that faces a street and is the same level as the street need not comply with Sentence (1) where the limiting distance is not less than 9 m.
(10)Except as provided in Sentence (11), for garages or accessory buildings that serve a single dwelling unit only and are detached from any building, the maximum aggregate area of glazed openings shall comply with the requirements for unprotected openings.
(11)The limits on the area of glazed openings need not apply to the exposing building face of a detached garage or accessory building facing a dwelling unit, where
(a)the detached garage or accessory building serves only one dwelling unit,
(b)the detached garage or accessory building is located on the same property as that dwelling unit, and
(c)the dwelling unit served by the detached garage or accessory building is the only major occupancy on the property.
Open OBC Div. B 9.10.14.4. in the code viewer
OBC Div. B 9.10.14.6. Minor Openings in Exposing Building Face
(1)An opening in an exposing building face not more than 130 cm² shall not be considered an unprotected opening.
Open OBC Div. B 9.10.14.6. in the code viewer
OBC Div. B Table 9.10.14.5. Minimum Construction Requirements for Exposing Building Faces — Forming Part of Sentence 9.10.14.5.(1)
Table 9.10.14.5 — Minimum Construction Requirements for Exposing Building Faces — Forming Part of Sentence 9.10.14.5.(1) Forming Part of Sentence 9.10.14.5.(1) Occupancy Classification of Building | Maximum Area of Unprotected Openings Permitted, % of Exposing Building Face Area | Minimum Required Fire-Resistance Rating | Type of Construction Required | Type of Cladding Required Residential, business and personal services, and low-hazard industrial | 0 - 10 | 1 h | Noncombustible | Noncombustible Residential, business and personal services, and low-hazard industrial | > 10 but ≤25 | 1 h | Combustible or noncombustible | Noncombustible Residential, business and personal services, and low-hazard industrial | > 25 but < 100 | 45 min | Combustible or noncombustible | Combustible or noncombustible Mercantile and medium-hazard industrial | 0 - 10 | 2 h | Noncombustible | Noncombustible Mercantile and medium-hazard industrial | > 10 but ≤25 | 2 h | Combustible or noncombustible | Noncombustible Mercantile and medium-hazard industrial | > 25 but < 100 | 1 h | Combustible or noncombustible | Combustible or noncombustible
Open OBC Div. B Table 9.10.14.5. in the code viewer
OBC Div. B 9.10.14.3A. Inadequate Firefighting Facilities
(1)Where there is no fire department or where a fire department is not organized, trained and equipped to meet the needs of the community, the required limiting distance determined from Sentences 9.10.14.4.(2), (5) and (6) and Sentence 9.10.14.5.(6), shall be doubled for a building that is not sprinklered.
Open OBC Div. B 9.10.14.3A. in the code viewer
OBC Div. B 9.10.16.2. Required Fire Blocks in Wall Assemblies
(1)Except as permitted in Sentence (2), fire blocks shall be provided to block off concealed spaces within wall assemblies, including spaces created by furring,
(a)at each floor level,
(b)at each ceiling level where the ceiling contributes to part of the required fire-resistance rating, and
(c)at other locations within the wall, so that the distance between fire blocks does not exceed 20 m horizontally and 3 m vertically.
(2)Fire blocks described in Sentence (1) are not required, provided
(a)the insulated wall assembly contains not more than one concealed air space whose horizontal thickness is not more than 25 mm,
(b)the exposed construction materials within the space are noncombustible, or
(c)the exposed construction materials within the space, including insulation, but not including wiring, piping or similar services, have a flame-spread rating of not more than 25, or
(d)the concealed wall space is filled with insulation.
Open OBC Div. B 9.10.16.2. in the code viewer
OBC Div. B 9.10.17.1. Flame-Spread Rating of Interior Surfaces
(1)Except as otherwise provided in this Subsection, the exposed surface of every interior wall and ceiling, including skylights and glazing, shall have a surface flame-spread rating of not more than 150.
(2)Except as permitted in Sentence (3), doors need not conform to Sentence (1) provided they have a surface flame-spread rating of not more than 200.
(3)Doors within dwelling units, other than garage doors, need not conform to Sentences (1) and (2).
Open OBC Div. B 9.10.17.1. in the code viewer
OBC Div. B 9.10.17.2. Ceilings in Exits or Public Corridors
(1)At least 90% of the exposed surface of every ceiling in an exit or ceiling that is not sprinklered in a public corridor shall have a surface flame-spread rating of not more than 25.
Open OBC Div. B 9.10.17.2. in the code viewer
OBC Div. B 9.10.17.3. Walls in Exits
(1)Except as provided in Sentence (2), at least 90% of the exposed surfaces of every wall in an exit shall have a surface flame-spread rating of not more than 25.
(2)At least 75% of the wall surface of a lobby used as an exit in Article 9.9.8.5. shall have a surface flame-spread rating of not more than 25.
Open OBC Div. B 9.10.17.3. in the code viewer
OBC Div. B 9.10.17.5. Walls in Public Corridors
(1)At least 90% of the total wall surface in any public corridor that is not sprinklered shall have a surface flame-spread rating of not more than 75, or at least 90% of the upper half of such walls shall have a surface flame-spread rating of not more than 25. (See Article 9.10.17.6.)
Open OBC Div. B 9.10.17.5. in the code viewer
OBC Div. B Table 9.10.18.2. Maximum Occupant Load for Buildings Without Fire Alarm Systems — Forming Part of Sentence 9.10.18.2.(2)
Table 9.10.18.2 — Maximum Occupant Load for Buildings Without Fire Alarm Systems — Forming Part of Sentence 9.10.18.2.(2) Forming Part of Sentence 9.10.18.2.(2) Major Occupancy Classification | Occupant Load Residential | 10 (sleeping accommodation) Business and personal services, mercantile | 150 above or below the first storey Low-or medium-hazard industrial | 75 above or below the first storey
Open OBC Div. B Table 9.10.18.2. in the code viewer
OBC Div. B 9.10.18.2. Fire Alarm System Required
(1)Reserved.
(2)Except as provided in Sentence (5), a fire alarm system shall be installed
(a)in every building that contains more than 3 storeys, including storeys below the first storey,
(b)where the total occupant load exceeds 300, or
(c)when the occupant load for any major occupancy in Table 9.10.18.2. is exceeded.
(3)Reserved.
(4)Reserved.
(5)A fire alarm system is not required in a residential occupancy where an exit or public corridor serves not more than 4 suites or where each suite has direct access to an exterior exit facility leading to ground level.
Open OBC Div. B 9.10.18.2. in the code viewer
OBC Div. B 9.10.19.1. Required Smoke Alarms
(1)Except as permitted by Article 9.10.19.8., smoke alarms conforming to CAN/ULC-S531, "Standard for Smoke Alarms," shall be installed in
(a)each dwelling unit,
(b)each sleeping room not within a dwelling unit, and
(c)ancillary spaces and common spaces not in dwelling units in a house with a secondary suite.
(2)Smoke alarms required in Sentence (1) shall have a visual signalling component conforming to the requirements in 18.5.3. (Light, Color and Pulse Characteristics) of NFPA 72, "National Fire Alarm and Signaling Code."
(3)The visual signalling component required in Sentence (2) need not
(a)be integrated with the smoke alarm provided it is interconnected to it,
(b)be on battery backup, or
(c)have synchronized flash rates, when installed in a house with a secondary suite or an individual dwelling unit.
(4)The luminous intensity for visual signalling components required in Sentence (2) that are installed in sleeping rooms shall be a minimum of 175 cd.
Open OBC Div. B 9.10.19.1. in the code viewer
OBC Div. B 9.10.19.4. Power Supply
(1)Except as provided in Sentences (2) and (3), smoke alarms described in Sentence 9.10.19.1.(1) and 9.10.19.3.(1.1) shall
(a)be installed with permanent connections to an electrical circuit, (See Note A-3.2.4.20.(9) (a))
(b)have no disconnect switch between the overcurrent device and the smoke alarm, and
(c)in case the regular power supply to the smoke alarm is interrupted, be provided with a battery as an alternative power source that can continue to provide power to the smoke alarm for a period of not less than 7 days in the normal condition, followed by 4 minutes of alarm.
(2)Where the building is not supplied with electrical power, smoke alarms are permitted to be battery-operated.
(3)Suites of residential occupancy are permitted to be equipped with smoke detectors in lieu of smoke alarms, provided the smoke detectors
(a)are capable of independently sounding audible signals with a sound pressure level between 75 dBA and 110 dBA within the individual suites, (See also Note A-3.2.4.18.(4))
(b)except as permitted in Sentence (4), are installed in conformance with CAN/ULC-S524, "Standard for Installation of Fire Alarm Systems," and
(c)form part of the fire alarm system. (See Note A-9.10.19.5.(2))
(4)Smoke detectors permitted to be installed in lieu of smoke alarms as stated in Sentence (3) are permitted to sound localized alarms within individual suites, and need not sound an alarm throughout the rest of the building.
Open OBC Div. B 9.10.19.4. in the code viewer
OBC Div. B 9.10.20.1. Windows or Access Panels Required
(1)Except as provided in Sentence (3), a window or access panel providing an opening not less than 1,100 mm high and 550 mm wide and having a sill height of not more than 900 mm above the floor shall be provided on the second and third storeys of every building in at least one wall facing on a street if such storeys are not sprinklered.
(2)Access panels required in Sentence (1) shall be readily openable from both inside and outside or be glazed with plain glass.
(3)Access panels required in Sentence (1) need not be provided in
(a)buildings containing only dwelling units where there is no dwelling unit above another dwelling unit, or
(b)houses with a secondary suite.
Open OBC Div. B 9.10.20.1. in the code viewer
OBC Div. B 9.11.1.1. Required Protection
(1)Except as provided in Sentence (3), a dwelling unit and a suite in hotels shall be separated from every other space in a building in which noise may be generated by
(a)a separating assembly and adjoining constructions, which, together, provide an apparent sound transmission class (ASTC) rating of not less than 47, or
(b)a separating assembly that provides a sound transmission class (STC) rating of at least 50 and adjoining constructions that conforms to Article 9.11.1.4. (See Note A-9.11.1.4.)
(2)Reserved.
(3)Construction separating a dwelling unit or suite in a hotel from an elevator shaft or refuse chute shall have an STC rating of not less than 55.
Open OBC Div. B 9.11.1.1. in the code viewer