BCAB #1687 - Fire Protection of Exterior Exit Stair, Articles 184.108.40.206. & 220.127.116.11
January 20, 2011
Re: Fire Protection of Exterior Exit Stair, Articles 18.104.22.168. & 22.214.171.124
The project in question is a large sports complex incorporating a speed skating oval, hockey rinks and an upper level running track. The building is designed and constructed as Group A Division 3 major occupancy under Article 126.96.36.199. There are two exterior exit stairs serving the top floor running track.
Reason for Appeal
Article 188.8.131.52. requires exits to be separated from the remainder of the building by a fire separation with a specified fire resistance rating dependent on the required fire resistance rating of the floor assemblies but not less than 45 minutes nor more than 2 hours. Sentence 184.108.40.206.(2) requires openings within specified distances from an exterior exit stair to be protected with wired glass, glass block or a closure.
The appellant contends that no fire separation is necessary for the exterior stairs as they do not pass through the floor assemblies, there are no unprotected openings within 3 metres of them and the 15 minute fire resistance rating of the exterior wall assemblies is more than adequate to protect the stairs when it would only take about one minute to descend them.
Building Official's Position
The building official maintains that the requirement to provide a fire separation between the exit stair and the remainder of the building is not contingent on whether or not the stair passes through a fire rated floor assembly. Sentence 220.127.116.11.(1) requires an exit to be separated from the building which is, by definition, everything within the exterior walls. The fire resistance of the separation is based on the rating of the building’s floor assemblies, in this case 2 hours. The fact that the stairs do not penetrate the floor assemblies is not relevant.
Appeal Board Decision #1691
It is the determination of the Board that the exterior exit stair must be separated by providing a 2 hour fire resistance rating to the exterior wall adjacent to the stair. The fire resistance rating is required to encompass the rectangular area defined by the attached illustration. The exterior wall and door at the second floor landing must also have the fire resistance rating. The Board notes that if the mechanical louvers and adjacent doors are within the distances described in Sentence 18.104.22.168.(2), i.e. 3 m horizontally, protection will be required.
George Humphrey, Chair