The British Columbia Building Code | Notes to Part 3 | Fire Protection, Occupant Safety and Accessibility Pt 2

Division B: Acceptable Solutions Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility
British Columbia Building Code 2018 Revision 2.01 Division B
Notes to Part 3
Fire Protection, Occupant Safety and Accessibility
A-3 Application of Part 3. In applying the requirements of this Part, it is intended that they be applied with discretion to
buildings of unusual configuration that do not clearly conform to the specific requirements, or to buildings in which processes are
carried out which make compliance with particular requirements in this Part impracticable. The definition of “building” as it applies to
this Code is general and encompasses most structures, including those which would not normally be considered as buildings in the
layman’s sense. This occurs more often in industrial uses, particularly those involving manufacturing facilities and equipment that
require specialized design that may make it impracticable to follow the specific requirements of this Part. Steel mills, aluminum plants,
refining, power generation and liquid storage facilities are examples. A water tank or an oil refinery, for example, has no floor area,
so it is obvious that requirements for exits from floor areas would not apply. Requirements for structural fire protection in large steel
mills and pulp and paper mills, particularly in certain portions, may not be practicable to achieve in terms of the construction normally
used and the operations for which the space is to be used. In other portions of the same building, however, it may be quite reasonable
to require that the provisions of this Part be applied (e.g., the office portions). Similarly, areas of industrial occupancy which may be
occupied only periodically by service staff, such as equipment penthouses, normally would not need to have the same type of exit
facility as floor areas occupied on a continuing basis. It is expected that judgment will be exercised in evaluating the application of a
requirement in those cases when extenuating circumstances require special consideration, provided the occupants’ safety is not
endangered.
The provisions in this Part for fire protection features installed in buildings are intended to provide a minimum acceptable level of
public safety. It is intended that all fire protection features of a building, whether required or not, will be designed in conformance
with good fire protection engineering practice and will meet the appropriate installation requirements in relevant standards.
Good design is necessary to ensure that the level of public safety established by the Code requirements will not be reduced by a
voluntary installation.
Firefighting Assumptions
The requirements of this Part are based on the assumption that firefighting capabilities are available in the event of a fire
emergency. These firefighting capabilities may take the form of a paid or volunteer public fire department or in some cases a
private fire brigade. If these firefighting capabilities are not available, additional fire safety measures may be required.
Firefighting capability can vary from municipality to municipality. Generally, larger municipalities have greater firefighting
capability than smaller ones. Similarly, older, well established municipalities may have better firefighting facilities than newly
formed or rapidly growing ones. The level of municipal fire protection considered to be adequate will normally depend on both
the size of the municipality (i.e., the number of buildings to be protected) and the size of buildings within that municipality.
Since
larger buildings tend to be located in larger municipalities, they are generally, but not always, favoured with a higher level of
municipal protection.
Although it is reasonable to consider that some level of municipal firefighting capability was assumed in developing the fire safety
provisions in Part 3, this was not done on a consistent or defined basis. The requirements in the Code, while developed in the
light of commonly prevailing municipal fire protection levels, do not attempt to relate the size of building to the level of
municipal protection. The responsibility for controlling the maximum size of building to be permitted in a municipality in relation
to local firefighting capability rests with the municipality. If a proposed building is too large, either in terms of floor area or
building height, to receive reasonable protection from the municipal fire department, fire protection requirements in addition to
those prescribed in this Code, may be necessary to compensate for this deficiency. Automatic sprinkler protection may be one
option to be considered.
Alternatively, the municipality may, in light of its firefighting capability, elect to introduce zoning restrictions to ensure that the
maximum building size is related to available municipal fire protection facilities. This is, by necessity, a somewhat arbitrary
decision and should be made in consultation with the local firefighting service, who should have an appreciation of their
capability to fight fires.
The requirements of Subsection 3.2.3. are intended to prevent fire spread from thermal radiation assuming there is adequate
firefighting available. It has been found that periods of from 10 to 30 minutes usually elapse between the outbreak of fire in a
building that is not protected with an automatic sprinkler system and the attainment of high radiation levels. During this period,
the specified spatial separations should prove adequate to inhibit ignition of an exposed building face or the interior of an
adjacent building by radiation. Subsequently, however, reduction of the fire intensity by firefighting and the protective wetting of
the exposed building face will often be necessary as supplementary measures to inhibit fire spread.
Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility Division B: Acceptable Solutions
Division B Revision 2.01 British Columbia Building Code 2018
In the case of a building that is sprinklered throughout, the automatic sprinkler system should control the fire to an extent that
radiation to neighbouring buildings should be minimal. Although there will be some radiation effect on a sprinklered building
from a fire in a neighbouring building, the internal sprinkler system should control any fires that might be ignited in the building
and thereby minimize the possibility of the fire spreading into the exposed building. NFPA 80A, “Protection of Buildings from
Exterior Fire Exposures,” provides additional information on the possibility of fire spread at building exteriors.
The water supply requirements for fire protection installations depend on the requirements of any automatic sprinkler
installations and also on the number of fire streams that may be needed at any fire, having regard to the length of time the streams
will have to be used. Both these factors are largely influenced by the conditions at the building to be equipped, and the quantity
and pressure of water needed for the protection of both the interior and exterior of the building must be ascertained before the
water supply is decided upon. Acceptable water supplies may be a public waterworks system that has adequate pressure and
discharge capacity, automatic fire pumps, pressure tanks, manually controlled fire pumps in combination with pressure tanks,
gravity tanks, and manually controlled fire pumps operated by remote control devices at each hose station.
A-3.1.2. Use Classification. The purpose of classification is to determine which requirements apply. This Code requires
classification in accordance with every major occupancy for which the building is used or intended to be used. Where necessary,
an application clause has been inserted in this Part to explain how to choose between the alternative requirements which multiple
occupancy classification may present.
A-3.1.2.1.(1) Major Occupancy Classification. The following are examples of the major occupancy classifications
described in Table 3.1.2.1.:
Group A, Division 1
Motion picture theatres
Opera houses
Television studios admitting a viewing audience
Theatres, including experimental theatres
Group A, Division 2
Art galleries
Auditoria
Bowling alleys
Churches and similar places of worship
Clubs, nonresidential
Community halls
Courtrooms
Dance halls
Daycare Facilities for Children
Exhibition halls (other than classified in Group E)
Gymnasia
Lecture halls
Libraries
Licensed beverage establishments
Museums
Passenger stations and depots
Recreational piers
Restaurants
Schools and colleges, nonresidential
Undertaking premises
Group A, Division 3
Arenas
Indoor swimming pools, with or without spectator seating
Rinks
Division B: Acceptable Solutions Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility
British Columbia Building Code 2018 Revision 2.01 Division B
Group A, Division 4
Amusement park structures (not elsewhere classified)
Bleachers
Grandstands
Reviewing stands
Stadia
Group B, Division 1
Jails
Penitentiaries
Police stations with detention quarters
Prisons
Psychiatric hospitals with detention quarters
Reformatories with detention quarters
Group B, Division 2
Care facilities with treatment
Convalescent /recovery/rehabilitation centres with treatment
Hospices with treatment
Hospitals
Infirmaries
Nursing homes with treatment
Psychiatric hospitals without detention quarters
Respite centres with treatment
Group B, Division 3
Assisted/supportive living facilities
Care facilities without treatment
Children’s custodial homes
Convalescent/recovery/rehabilitation centres without treatment
Group homes
Hospices without treatment
Nursing homes without treatment
Reformatories without detention quarters
Respite centres without treatment
Group C
Apartments
Boarding houses
Clubs, residential
Colleges, residential
Convents
Dormitories
Hotels
Houses
Lodging houses
Monasteries
Motels
Schools, residential
Group D
Banks
Barber and hairdressing shops
Beauty parlours
Dental offices
Dry cleaning establishments, self-service, not using flammable or explosive solvents or cleaners
Laundries, self-service
Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility Division B: Acceptable Solutions
Division B Revision 2.01 British Columbia Building Code 2018
Medical offices
Offices
Police stations without detention quarters
Radio stations
Small tool and appliance rental and service establishments
Group E
Department stores
Exhibition halls
Markets
Shops
Stores
Supermarkets
Group F, Division 1
Bulk plants for flammable liquids
Bulk storage warehouses for hazardous substances
Cereal mills
Chemical manufacturing or processing plants
Distilleries
Dry cleaning plants
Feed mills
Flour mills
Grain elevators
Lacquer factories
Mattress factories
Paint, varnish and pyroxylin product factories
Rubber processing plants
Spray painting operations
Waste paper processing plants
Group F, Division 2
Aircraft hangars
Box factories
Candy plants
Cold storage plants
Dry cleaning establishments not using flammable or explosive solvents or cleaners
Electrical substations
Factories
Freight depots
Helicopter landing areas on roofs
Laboratories
Laundries, except self-service
Mattress factories
Planing mills
Printing plants
Repair garages
Salesrooms
Service stations
Storage rooms
Television studios not admitting a viewing audience
Warehouses
Wholesale rooms
Woodworking factories
Workshops
Division B: Acceptable Solutions Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility
British Columbia Building Code 2018 Revision 2.01 Division B
Group F, Division 3
Creameries
Factories
Laboratories
Light-aircraft hangars (storage only)
Power plants
Salesrooms
Sample display rooms
Storage garages, including open air parking garages
Storage rooms
Warehouses
Workshops
A-3.1.2.3.(1) Arena Regulation. The use of an arena is regulated in the British Columbia Fire Code.
A-3.1.2.6. Group A, Division 2, Low Occupant Load. A suite of Group A, Division 2 assembly is permitted to be
classified as a Group D business and personal services occupancy provided the requirements of Article 3.1.2.6. are complied with.
This re-classification permits the suite to be located in a building to which Part 9 of the Code is applicable.
A-3.1.2.8. Daycare Facilities for Children. A daycare facility for children is typically occupied for a period of less than
24 hours each day (i.e., is not a residential facility). The term “daycare” is not meant to exclude facilities that provide short term care
during the night for a period of less than 24 hours each day. (See also A-3.3.2.17.)
A-3.1.4.1.(1) Combustible Construction and Materials Permitted. The permission to use combustible construction or
combustible materials stated in Articles 3.1.4.1., 3.1.5.5., 3.1.5.14. and 3.1.5.15. does not waive the requirements regarding
construction type and cladding stated in Article 3.2.3.7.
A-3.1.4.2. Protection of Penetrations. Where foamed plastics are required to be protected from adjacent spaces within a
building, the protection should be continuous so as to cover the foamed plastics so they are not exposed to the interior of the
building. However, minor penetrations of the protective covering by small electrical and mechanical components, such as electrical
outlets and fixtures, sprinkler piping, and mechanical vents, are acceptable because the penetrant and associated fittings and seals will
prevent the small amount of foamed plastic surrounding the penetration from being exposed to the interior of the building.
Foamed plastics that are penetrated by larger components or assemblies, such as windows, are unlikely to be exposed to the interior of
the building as they are protected by associated framing and finishes and/or the installation of a closure.
Small amounts of foamed plastics, such as air sealants used between major components of exterior wall construction, are not required
to be protected (see Sentence 3.1.5.2.(1)).
Penetrations of a fire separation or of a membrane forming part of an assembly required to have a fire-resistance rating are
nevertheless required to be provided with a fire stop in accordance with Subsection 3.1.9.
A-3.1.4.2.(1) Concealed Space. The term “concealed space” includes any space that is not visibly apparent and that is
provided with an opening to allow access for repair and periodic inspections.
A-3.1.4.2.(1)(c) Thermal Barrier in Combustible Construction. Any thermal barrier that is accepted under the
requirements of Sentence 3.1.5.15.(2) for noncombustible construction is also acceptable for combustible construction.
A-3.1.4.2.(2) and 3.1.5.7.(3) Walk-in Coolers and Freezers. Sentences 3.1.4.2.(2) and 3.1.5.7.(3) are intended to apply to
walk-in coolers and freezers that are constructed as stand-alone structures within a building.
A-3.1.4.3.(1)(b)(i) Raceway Definition. The term raceway is defined in CSA C22.1, “Canadian Electrical Code, Part I,” and
includes both rigid and flexible conduit.
A-3.1.4.3.(1) Wire and Cable Equivalence. Electrical wires and cables that conform to the requirements of
Sentence 3.1.5.21.(1) are deemed to satisfy the requirements of Sentence 3.1.4.3.(1).
Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility Division B: Acceptable Solutions
Division B Revision 2.01 British Columbia Building Code 2018
A-3.1.4.8.(1) Exterior Cladding. The requirements in Sentence 3.1.4.8.(1) are intended to limit the potential for fire spread
on the exterior cladding of buildings of combustible construction through the use of noncombustible finishes on the exterior of the
wall assembly or the use of a cladding/wall assembly that has been assessed with regard to its ability to resist flame propagation up the
outside of a building. These cladding and wall assembly combinations can be used as infill or panel-type walls between structural
elements, or attached directly to a loadbearing structural system. Note that these requirements apply independently of the provisions
contained in Subsection 3.2.3. regarding spatial separation and exposure protection.
A-3.1.5.4.(1) Skylight Spacing. The minimum spacing dimensions for skylight assemblies are based on the distance that
flame must travel along a flat ceiling surface. If ceilings have projecting beams or other features that would increase the distance the
flame would have to travel along the surface, the distances specified may be measured accordingly.
A-3.1.5.5.(1)(b) Combustible Cladding on Exterior Walls. The performance of the wall assembly is assessed with regard
to its ability to resist flame propagation up the outside of a building.
A-3.1.5.5.(1)(b)(i) Flame-Spread Distance. The maximum flame-spread distance referred to in Subclause 3.1.5.5.(1)(b)(i)
means the distance between the top of the opening and the highest observable instance of flaming along the wall assembly; thus,
intermittent flaming to a height of 5 m above the opening is acceptable.
A-3.1.5.5.(1)(b)(ii) Heat Flux Measurement. The heat flux to the assembly referred to in Subclause 3.1.5.5.(1)(b)(ii) is the
maximum one-minute averaged heat flux measured by transducers located 3.5 m above the top of the opening. The intent of this
criterion is to limit the spread of fire on the wall assembly to a height of 3.5 m above the opening.
Fire tests have shown that flame does not spread on the exterior surface of a wall assembly where the heat flux is less than 35 kW/m
2
above the opening.
A-3.1.5.14.(5)(d) Foamed Plastic Insulation Protection. The standard fire exposure temperature in CAN/ULC-S101,
“Fire Endurance Tests of Building Construction and Materials,” is the same as in CAN/ULC-S124, “Test for the Evaluation of
Protective Coverings for Foamed Plastic.” A thermal barrier that, when tested in conformance with CAN/ULC-S101, does not
exceed an average temperature rise of 140°C on its unexposed face after a period of 10 min satisfies this requirement.
A-3.1.5.21.(1) Wire and Cable Flammability. In regulating the flammability characteristics of electrical wires and cables
installed in a building, it is intended that the requirements of this Sentence and of other similar Sentences in the Code apply to wires
and cables that are essentially a part of the distribution systems for power or communications. These distribution systems will
normally include branch circuits that terminate at an outlet box in the space to be served and at that location cable terminators or
plugs for individual items of equipment will be plugged in.
A-3.1.6. Tents and Air-Supported Structures. The requirements in this Subsection are intended to be limited to certain
types of structure. For instance, the word “tent” as used in the Code is intended to refer to a temporary shelter which is used at an
open air event such as a fair or an exhibition. A tent will normally be constructed of a fabric held up by poles and attached to the
ground by ties. The requirements for tents, however, are not intended to be applied to fabric structures located on buildings.
The term “air-supported structure,” as used in the Code, refers to an envelope which is held up by air pressure alone and which is
erected on the ground or above a basement. The structure will usually require ballast or a positive ground anchorage system around
the entire perimeter to secure it to the ground or basement. To reinforce this intent, the Code prohibits the location of an
air-supported structure above the first storey of any building.
The requirements of Subsection 3.1.6. are not intended to apply to air-supported roof assemblies on buildings, such as domed stadia,
or to other types of air-supported structures, such as those over swimming pools situated on the roofs of buildings, which would not
be anchored at or near ground level. These assemblies or structures are normally designed and evaluated on the basis of alternative
solutions as permitted by Article 1.2.1.1. of Division A.
A-3.1.8.1.(1)(b) Barrier to Control Smoke Spread. Although a fire separation is not always required to have a
fire-resistance rating, the fire separation should act as a barrier to the spread of smoke and fire until some response is initiated.
When choosing products for fire stopping, the physical characteristics of the material used at the joints as well as the nature of the
assembly and its potential movement should be taken into consideration.
If the fire-resistance rating of a fire separation is waived on the basis of the presence of an automatic sprinkler system, it is intended
that the fire separation will be constructed so that it will remain in place and act as a barrier against the spread of smoke for a period
of time until the sprinklers have actuated and controlled the fire.
Division B: Acceptable Solutions Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility
British Columbia Building Code 2018 Revision 2.01 Division B
A-3.1.8.1.(2) Installation of Closures. Although there is no explicit performance statement in the British Columbia
Building Code that means of egress should be free of smoke, it is the intent that during the period when occupants are using a means
of egress to evacuate from a floor area, the smoke contamination should not reach levels that would inhibit movement to the exit.
This is particularly critical for persons with disabilities, who may not move at the same rate as other persons and who could be more
susceptible to the effects of smoke contamination. NFPA 80, “Fire Doors and Other Opening Protectives,” requires that a fire door
protecting a means of egress be designed to minimize the possibility of smoke passing through the opening.
Although self-closing devices are not required for all doors in a fire separation (see Article 3.1.8.13.), it is assumed that in a fire
situation every door in a fire separation is closed. Article 3.3.3.5. prohibits grilles and similar openings for certain doors in hospitals
and nursing homes with treatment.
Although fire dampers that release on the fusion of a fusible link will help to control the spread of fire, a substantial quantity of smoke
could have passed through the opening before that event. They are frequently located below the upper levels of a room and so the
release of the fusible link of the fire damper that protects an opening will be delayed until the temperature at the level of the opening
becomes high enough to fuse the link.
Similar concern has to be considered for other closure devices that are permitted to remain open on fusible links, and their location
should be restricted in accordance with NFPA 80 and the British Columbia Building Code, except where their installation in another
location will not allow the products of combustion to spread into means of egress.
A-3.1.8.3.(4) Fire Separation Continuity. The continuity of a fire separation where it abuts against another fire separation,
a floor, a ceiling or an exterior wall assembly is maintained by filling all openings at the juncture of the assemblies with a material that
will ensure the integrity of the fire separation at that location.
A-3.1.8.10.(1) Combination Smoke/Fire Dampers. A combination smoke/fire damper may be used in lieu of a fire
damper to meet the requirement of Sentence 3.1.8.10.(3).
A-3.1.8.10.(5) Damper Access. It is intended that an access door be provided in the duct and, if the duct is enclosed with an
architectural finish, that a second access door be provided through that finish.
A-3.1.8.18.(1) Wired Glass and Glass Block. The permission to include wired glass and glass block in doors and fire
separations between an exit and the adjacent floor area does not permit the inclusion of those items in fire separations between exits
and other parts of the building that are not included in the floor area. Examples include other exit facilities and vertical service spaces,
including those used for building services and elevator hoistways.
A-3.1.8.19.(1) Fire-Protection Rating for Doors. The provisions in Articles 3.1.8.17., 3.1.8.18. and 3.1.8.19. do not waive
a requirement for a door to have a fire-protection rating. To achieve this rating in a door test, it may be necessary to limit the area of
glass in the door. If this area is less than the area limits of Article 3.1.8.18., it is the governing criterion. Conversely, if the area limits of
Article 3.1.8.18. are less than the area required to achieve a fire-protection rating, then the area limits of this Article govern.
A-3.1.9. Penetrations. In the application of Subsection 3.1.9., a building service is considered to penetrate an assembly if it
passes into or through the assembly. In some situations a service item enters an assembly through a membrane at one location, runs
within the assembly, and then leaves the assembly through a membrane at another location.
The term “membrane penetration” usually designates an opening made through one side (wall, floor or ceiling membrane) of an
assembly, whereas the term “through-penetration” designates an opening that passes through an entire assembly. Fire stopping of
membrane penetrations involves installing a material, device or construction to resist for a prescribed time period the passage of flame
and heat through openings in a protective membrane caused by cables, cable trays, conduit, tubing, pipes or similar items.
Fire stopping of a through-penetration involves installing an assemblage of specific materials or products that are designed, tested and
fire-resistance rated to resist for a prescribed period of time the spread of fire through penetrations.
Products for fire stopping within a barrier are required to address movement of the assembly and to control smoke spread; as such,
the flexibility of the material used at the flexible joints as well as the nature of the assembly and its potential movement must be taken
into consideration.
A-3.1.9.1.(1)(b) Cast in Place Penetrations. The intention behind the use of the term “cast in place” is to reinforce that
there are to be no gaps between the building service or penetrating item and the membrane or assembly it penetrates. The term ”cast
in place” describes a typical means of fire stopping for a service penetration through a concrete slab or wall.
A-3.1.9.1.(1)(c) Tightly Fitted Penetrations. The intention behind the term “tightly tted” is to reinforce that there are to
be no substantial gaps between the building service or penetrating item and the membrane or assembly it penetrates.
Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility Division B: Acceptable Solutions
Division B Revision 2.01 British Columbia Building Code 2018
A-3.1.9.2.(1) Penetration of Fire Separations by Electrical Boxes. The provisions dealing with outlet boxes assume
size, quantities and concentrations of partial depth penetrations that would not significantly affect the fire resistance of the assembly,
including the temperature rise on the unexposed side of a wall. Sentence 3.1.9.2.(1) is not intended to allow large electrical distribution
and control boxes to be recessed into an assembly required to have a fire-resistance rating unless they were incorporated in the
assembly at the time of testing.
A-3.1.9.4. Outlet Boxes. For the purposes of Article 3.1.9.4., outlet boxes include, but are not limited to, electrical boxes,
junction boxes, high and low voltage outlets, switches, enclosures for electrical equipment, laundry boxes, and shower diverters.
A-3.1.10.2.(4) Firewall Construction. Inherent in the use of a firewall is the intent that this specialized wall construction
provide the required fire-resistance rating while also being designed to resist physical damage – arising out of normal use – that would
compromise the rating of the assembly. Traditionally, this has been accomplished by prescribing the use of noncombustible materials,
which was in fact restricted to concrete or masonry. Sentences 3.1.10.2.(3) and (4) are intended to retain both of the characteristics of
firewalls, while permitting greater flexibility in the use of materials and designs. The fire-resistance rating and damage protection
attributes of a firewall may be provided by a single fire- and damage-resistant material such as concrete or masonry, by a fire- and
damage-resistant membrane on a structural frame, or by separate components – one that provides the fire-resistance rating and
another one that protects the firewall against damage.
If the firewall is composed of separate components, the fire-resistance rating of the fire-resistive component needs to be determined
for this assembly on its own. In addition, if the damage protection component is physically attached to the fire-resistive component
(for example, as a sacrificial layer), then for the purposes of determining the overall performance of the assembly, it is also necessary to
determine through testing whether failure of the damage protection component during a fire affects the performance of the
fire-resistive component.
A-3.1.11.3.(3) Fire Blocks Between Nailing and Supporting Elements. Sentence 3.1.11.3.(3) addresses cases in
buildings or parts of buildings permitted to be of encapsulated mass timber construction where, in accordance with Sentence
3.1.18.12.(3), 10% of the ceiling finish within a fire compartment is permitted to have a flame-spread rating not more than 150.
Where such combustible ceiling finish is attached using nailing elements and a concealed space is formed above, exposed combustible
elements in this space would require fire blocks to limit fire spread in this area.
A-3.1.11.5.(1) Fire Blocks in Combustible Construction. Combustible construction referred to in Sentence 3.1.11.5.(1)
includes all types of construction that do not comply with the requirements for noncombustible construction or encapsulated mass
timber construction. All the elements within the concealed space can be combustible, unless required to be of noncombustible
materials (e.g., certain categories of pipework and ducts), but the value of the flame-spread rating of the combustible materials
determines the permitted extent of the concealed space between fire blocks. The materials to be considered include all construction
materials regulated by this Code, including the framing and building services that are located in the concealed space. When designing
fire blocking, consideration should be given to avoid restricting venting capabilities within concealed spaces. (See also Note A-5.6.2.1.)
A-3.1.11.5.(3) Fire Blocks in Concealed Spaces. To reduce the risk of fire spread in combustible concealed spaces
within the types of buildings referred to in Sentences
3.1.11.5.(3) and (4), fire blocking is required regardless of whether the horizontal
concealed space is protected by sprinklers or not, unless the space is filled with noncombustible insulation so that any air gap at the
top of the insulation is very small. See also Note A-3.1.11.5.(1) for roof venting.
A 5- or 6-storey building constructed in accordance with Article 3.2.2.50. and buildings constructed in accordance with
Article 3.2.2.48EMTC., 3.2.2.57EMTC., or
3.2.2.58. are required to be sprinklered in accordance with NFPA 13, “Installation of
Sprinkler Systems” (see Article 3.2.5.12.). NFPA 13 generally requires sprinklering of any concealed spaces of combustible
construction or where large amounts of combustibles are present. However, NFPA 13 allows combustible concealed spaces to be
unsprinklered in certain cases, including where concealed spaces are filled almost entirely with noncombustible insulation, where
spaces contain only materials with a low flame-spread rating, and where limited access or the size of the space makes it impractical to
install sprinklers. For certain types of construction in unsprinklered combustible concealed spaces, NFPA 13 mandates fire blocking
beyond the minimum specified in Sentence 3.1.11.5.(3).
A-3.1.11.7.(7
) Integrity of Fire Blocks. Sentence 3.1.11.7.(7) together with Article 3.1.9.1., is intended to ensure that the
integrity of fire blocks is maintained at areas where they are penetrated. This requirement is satisfied by the use of generic fire stops
such as mineral wool, gypsum plaster or Portland cement mortar, as well as rated fire stops.
Division B: Acceptable Solutions Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility
British Columbia Building Code 2018 Revision 2.01 Division B
A-3.1.11.7.(8) Fire Blocks. Figure A-3.1.11.7.(8) shows the location of the semi-rigid fibre insulation board at the intersection
between walls and floors in wood-frame construction. The figure is intended to illustrate the fire block detail and not a design of a
fire separation.
Figure A-3.1.11.7.(8)
Fire block
A-3.1.13.2.(2) Folding Partition. Folding partitions used to divide a space into separate rooms are not considered as doors
for the purposes of this Sentence.
A-3.1.18.
Encapsulated Mass Timber Construction and Materials Permitted. The permission to use encapsulated
mass timber construction and other combustible materials stated in Articles 3.1.18.2., 3.1.18.3., 3.1.18.7. and 3.1.18.8. does not waive
the requirements regarding types of construction and cladding stated in Article 3.2.3.7.
A-3.1.18.3. Structural Mass Timber Elements. Structural timber elements may consist of any number of large
cross-section timber products, such as solid-sawn timber, glued-laminated timber (glulam), structural composite lumber (SCL),
cross-laminated timber (CLT), and nail-laminated timber (NLT).
The minimum dimensions required for structural timber elements in encapsulated mass timber construction were established so that
such elements will exhibit the fire performance characteristics of mass timber rather than those of lightweight, small-dimensioned
wood elements (e.g., lumber), including reduced ignition propensity and reduced average rate of fuel contribution. Note that the
dimensions stated in Table 3.1.18.3. do not reflect a specific fire-resistance rating; larger dimensions may be required to satisfy
fire-resistance rating requirements.
The reference to Article 3.2.2.16. means that heavy timber construction is permitted to be used for the roof assembly (and its
supports) in buildings of encapsulated mass timber construction that are sprinklered and not more than 2 storeys in building height.
It follows that the minimum dimensions stated in Table 3.1.4.7. would apply to those elements rather than the ones stated in
Table 3.1.18.3. Furthermore, the roof elements and supports made of heavy timber construction do not need to conform to the
encapsulation requirements of Article 3.1.18.4., nor are they limited by the flame-spread rating or maximum thickness or cut-through
requirements of Article 3.1.18.12.
A-Table 3.1.18.3. Minimum Dimensions of Structural Timber Elements. The minimum dimensions for floor
assemblies are also applicable to mezzanines and exterior balconies.
semi-rigid fibre
insulation board
fastened to one
set of studs
joist
joist
EG02044A
Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility Division B: Acceptable Solutions
Division B Revision 2.01 British Columbia Building Code 2018
A-3.1.18.4.(1) Encapsulation of Mass Timber Elements. The general intent of Sentence 3.1.18.4.(1) is that all exposed
surfaces of the mass timber elements be encapsulated, including the upper surface of a mass timber floor assembly, but some
exceptions do apply. The upper surface of a mass timber roof assembly need not be encapsulated when there is no concealed space
above it. As well, the exterior side of a mass timber exterior wall assembly need not be encapsulated, however, the provisions of
Article 3.1.18.7. and Subsection 3.2.3. for exterior walls still need to be considered. A number of concealed space arrangements are
also exempt from this general requirement of encapsulation (i.e. Sentences 3.1.18.3.(4) and 3.1.18.14.(2), Articles 3.1.18.5., 3.1.18.10.
and 3.1.18.15.).
A-3.1.18.4.(3) to (6) Fire-Resistance Rating of Mass Timber with Exposed Surfaces. Portions of mass timber
elements required to have a fire-resistance rating are permitted to be exposed in accordance with the permissions stated in
Sentences 3.1.18.4.(3) to (6); however, it is important to note that applying those permissions does not waive the requirement for these
elements to have a fire-resistance rating.
A-3.1.18.4.(4) Exposed Surfaces of Mass Timber Walls. The primary objective of encapsulating mass timber elements
is to limit the probability that these elements will significantly contribute to fire spread and fire duration in the event of a fire.
Since thick wood members require a source of imposed heat flux to burn, the stipulation in Clause 3.1.18.4.(4)(a) that the exposed
surfaces of mass timber walls face the same direction within a suite is intended to reduce the potential of re-radiation between burning
mass timber surfaces that face each other, which could sustain flaming combustion into the decay phase of a fire if the sprinkler
system failed to operate or to control the fire. Additionally, the maximum percentage of exposed surface area stated in Article 3.1.18.4.
is low so that it is not sufficient to sustain a ventilation-controlled fire that might provide the radiation required to sustain flaming
combustion into the decay phase of a fire if the sprinkler system failed to operate or to control the fire.
A-3.1.18.7.(1) and (2) Exterior Cladding. The requirements in Sentences 3.1.18.7.(1) and (2) are intended to reduce the
potential for fire spread on the exterior cladding of buildings of encapsulated mass timber construction through the use of
noncombustible finishes on the exterior of the wall assembly or the use of a cladding/wall assembly that has been proven to resist
flame propagation. These cladding/wall assembly combinations can be used as infill or panel-type walls between structural elements,
or attached directly to a loadbearing structural system. Note that the requirements in Article 3.1.18.7. do not supersede the provisions
in Subsection 3.2.3. regarding spatial separation and exposure protection.
A-3.1.19.2. Encapsulation Materials. Research has been conducted on different types of encapsulation materials, such as
gypsum board, gypsum concrete and cement board. The results of tests using an intermediate-scale furnace and of cone calorimeter
tests indicate that a combustible timber element protected with a 38 mm thick layer of gypsum-concrete topping or with two layers of
12.7 mm Type X gypsum board will not ignite or contribute significant heat to a fire until average temperatures of 325–380°C are
attained at the interface between the encapsulation material or assembly of materials and the combustible substrate. These
temperatures are consistent with the ignition temperatures of wood-based materials.
A-3.1.19.2.(2) Protection of Gypsum Board from Foot Traffic. Where gypsum board is used as the encapsulation
material on the top of a mass timber floor assembly, it should be protected from physical impact arising from normal pedestrian traffic
that could damage it and possibly compromise its encapsulation rating.
Division B: Acceptable Solutions Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility
British Columbia Building Code 2018 Revision 2.01 Division B
A-3.2.1.1.(3) Mezzanine Area. The following sketches illustrate the intent of this Sentence.
Figure A-3.2.1.1.(3)-A
Concept of Horizontal Plane
Notes to Figure A-3.2.1.1.(3)-A
(1) The horizontal plane (A, the dashed line) is measured at the mezzanine floor finish line.
(2) At least 60% of the horizontal plane (B) must be open to the floorspace below.
Figure A-3.2.1.1.(3)-B
Intersection Point
Notes to Figure A-3.2.1.1.(3)-B
(1) This Figure describes Clause 3.2.1.1.(3)(a).
(2) The length of the horizontal plane (A) is taken from the rear of the mezzanine to the point at which it intersects a wall, ceiling, roof or other
major component.
A
B
100%
REAR OF
MEZZANINE
INTERSECTION
POINT
A
Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility Division B: Acceptable Solutions
Division B Revision 2.01 British Columbia Building Code 2018
Figure A-3.2.1.1.(3)-C
Projections, Including Guards
Notes to Figure A-3.2.1.1.(3)-C
(1) This Figure describes Clause 3.2.1.1.(3)(b).
(2) Projections should not be permitted below the horizontal plane (A, the dashed line). This includes large beams, trusses, the roofline, or any
other projection that will impede vision lines.
(3) Visual obstructions on the mezzanine may include 1 070 mm high guards, and columns, posts and other structural elements of a minor nature.
Figure A-3.2.1.1.(3)-D
Enclosed Spaces within a Mezzanine
Notes to Figure A-3.2.1.1.(3)-D
(1) This Figure describes Sentence 3.2.1.1.(7).
(2) The horizontal plane is demonstrated by the dashed line, A.
(3) Up to 10% of the horizontal plane may be enclosed. This must be located so as to avoid contravening the open requirements of Clause
3.2.1.1.(3)(b); in effect no dead areas are permitted.
If a floor has more than one mezzanine, each may be treated individually. For example in a one storey building with five tenancies,
each tenant would be permitted to have a mezzanine up to the limits indicated, without the building being considered two storeys in
building height. However, should one of the mezzanines exceed any of the limitations, the building would then be considered to be
two storeys in building height.
Regarding the floor space under a mezzanine, there are no restrictions on partition construction in this area. The space on the floor
beyond the mezzanine, i.e. below the open portion of the horizontal plane, should, with discretion, be visually open to view from the
mezzanine.
GUARD
INTERSECTION
POINT
B
A
100%
A
B
Division B: Acceptable Solutions Notes to Part 3 – Fire Protection, Occupant Safety and Accessibility
British Columbia Building Code 2018 Revision 2.01 Division B
A-3.2.1.1.(4) Mezzanines in Suites. The defined term “suite” in this case could be equally applicable to a suite in an
apartment or commercial building, or even an entire storey such as may occur in a curling rink. There may be more than one enclosed
mezzanine in the suite but in no instance can the combined total mezzanine area exceed 10% of the suite in which they are located.
Figure A-3.2.1.1.(4)-A
Mezzanines in Suites
Notes to Figure A-3.2.1.1.(4)-A
(1) This Figure describes Clause 3.2.1.1.(4)(b).
(2) Mezzanines up to 1