BCAB #1836

December 19, 2019

Re: Protection of Fire Separations from Potential Damage

Project Description

The project is a wood-framed, four-storey, sprinklered apartment building constructed over a non-combustible storage garage. The storage garage is separated from the apartment building above by a concrete slab constructed in conformance with Sentence 3.2.1.2.(1) to allow the storage garage to be considered as a separate building. A common elevator serves the apartment building and the storage garage. In the storage garage, the elevator shaft is enclosed by assemblies having a 2 h fire-resistance rating. The elevator shaft is constructed on three sides with rated concrete walls, which also support the floor assembly, and that meets the requirements of Article 3.1.7.5. The remaining non-loadbearing wall of the elevator shaft is proposed to be constructed with an assembly that includes steel studs, rock wool insulation, and two layers of type X gypsum board to meet the requirement for non-combustible construction with a 2 h fire-resistance rating.

Applicable Code Requirements

Sentences 3.2.1.2.(1) and 3.1.10.2.(4) of Division B of the British Columbia Building Code 2018.

3.2.1.2.(1) A basement used primarily as a storage garage is permitted to be considered as a separate building for the purposes of Subsection 3.2.2. and Sentences 3.2.5.12.(2) and (3), provided the floor and roof assemblies above the basement and the exterior walls of the basement above the adjoining ground level are constructed as fire separations of noncombustible construction having a fire-resistance rating not less than 2 h and protected in conformance with Clause 3.1.10.2.(4)(a), except as permitted by Sentence (2). (See Notes A-3.1.10.2.(4) and A-3.2.5.12.(2).)

3.1.10.2.(4) A firewall permitted to have a fire-resistance rating not more than 2 h need not be constructed of masonry or concrete, provided

a) the assembly providing the fire-resistance rating is protected against damage that would compromise the integrity of the assembly, and

b) the design conforms to Article 4.1.5.17.

(See Note A-3.1.10.2.(4).)

Decision being Appealed (Local Authority’s Position)

The local authority has determined that protection against damage described in Clause 3.1.10.2.(4)(a) applies to the fire separation required for the elevator shaft in the storage garage. The proposed assembly using type X gypsum board has not been tested to indicate that it meets the physical performance requirements for protection against damage.

Appellant's Position

The appellant maintains that the assembly using type X gypsum board as proposed is acceptable as it meets the requirement for a 2 h fire-resistance rating and that protection is not required.

Appeal Board Decision #1836

It is the determination of the Board that the BC Building Code does not require protection in conformance with Clause 3.1.10.2.(4)(a) for the gypsum board assembly with a 2 h fire-resistance rating.

Reason for Decision

The Board does not consider the rated walls for the elevator shaft to be an extension of the 2 h floor assembly constructed to Article 3.2.1.2. Further, Sentence 3.1.8.3.(4) regulates the continuity between the vertical fire separation and horizontal fire separation.

Sentence 3.2.1.2.(1) identifies that protection is only required for the floor and roof assemblies above the basements and the basement’s exterior walls above the adjoining ground. Interior walls of the storage garage are not included in the protection requirements.

Lyle Kuhnert

Chair, Building Code Appeal Board