BCAB #1867

July 22, 2021

Re: Required smoke dampers

Project description

The project consists of two buildings of residential occupancy on a single basement parking garage designed to Article 3.2.1.2. The buildings have been classified under Articles 3.2.2.47. and 3.2.2.50. One of the buildings is seven storeys in building height and the other is five storeys in building height. Pressurized vestibules have been used to separate the buildings as described in Sentence 3.2.6.3.(1). The building has been designed so that the high building measures will be applied to the seven-storey building and not to the five-storey building.

Applicable Code requirements

Sentences 3.1.8.7.(2), Subclause 3.1.8.9.(2)(a)(iii) and Sentence 3.2.6.2.(6) of the British Columbia Building Code 2018.

3.1.8.7.(2) Except as provided in Article 3.1.8.9., a smoke damper or a combination smoke/fire damper shall be installed in conformance with Article 3.1.8.11. in ducts or air-transfer openings that penetrate an assembly required to be a fire separation, where the fire separation

a) separates a public corridor,

b) contains an egress door referred to in Sentence 3.4.2.4.(2),

c) serves an assembly, care, treatment, detention or residential occupancy, or

d) is installed to meet the requirements of Clause 3.3.1.7.(1)(b) or Sentence 3.3.3.5.(4).

3.1.8.9.(2) The requirement for smoke dampers or a combination smoke/fire damper stated in Sentence 3.1.8.7.(2) is permitted to be waived for noncombustible branch ducts having a melting point above 760°C that penetrate a fire separation,

a) provided the ducts

i) have a cross-sectional area not more than 0.013 m² and serve only air-conditioning units or combination air-conditioning and heating units discharging air not more than 1.2 m above the floor,

ii) extend not less than 500 mm inside exhaust duct risers that are under negative pressure and in which the airflow is upward as required by Article 3.6.3.4., or

iii) are required to function as part of a smoke control system, or

b) where the fire separation separates a vertical service space from the remainder of the building, provided each individual duct exhausts directly to the outdoors at the top of the vertical service space.

3.2.6.2.(6) Except as provided in Article 3.2.4.12. or where there is a conflict with other smoke control measures in the building, air-handling systems used to provide make-up air to public corridors serving suites in a Group C major occupancy shall not shut down automatically upon activation of the fire alarm so as to maintain corridor pressurization.

Decision being appealed (local authority’s position)

The local authority has determined that smoke or combination fire/smoke dampers are required at each residential corridor where the corridor make up air duct penetrates the fire separation between the shaft and the corridor in the high (seven-storey) building and the low (five-storey) building.

Appellant's position

The appellant maintains that fire dampers, not smoke or combination fire/smoke dampers, are required at each residential corridor where the corridor make up air duct penetrates the fire separation between the shaft and the corridor in the high (seven-storey) building based on Sentence 3.2.6.2.(6). The appellant also maintains that similarly, smoke or fire/smoke dampers should not be required for the residential corridor make up air duct in the low (five-storey) building.

Appeal Board decision #1867

It is the determination of the Board that smoke or combination fire/smoke dampers are required at each residential corridor where the corridor make up air duct penetrates the fire separation between the shaft and the corridor in both buildings. This requirement is waived if the ducts are required to function as part of a smoke control system.

Reason for decision

Subclause 3.1.8.9.(2)(a)(iii) says smoke dampers are waived in ducts that are required to function as part of a smoke control system. Designing the corridor make up air system as part of a smoke control system is an option.

Frankie Victor

Vice-chair, Building Code Appeal Board