BCAB #1253 - Windows in a Firewall Above a Roof - Sentences 22.214.171.124.(6) and 126.96.36.199.(1)
June 26, 1991
Re: Windows in a Firewall Above a Roof - Sentences 188.8.131.52.(6) and 184.108.40.206.(1)
A single storey addition adjacent to an existing three storey hospital. The exterior wall of the existing hospital is intended to act as a firewall to separate the existing building from the new building. The new building is fully sprinklered.
Reason for Appeal
There are unprotected openings (windows) in the wall of the existing building overlooking the roof of the addition.
The appellant proposes to protect the window openings with wired glass in steel frames and sprinklers and contends this meets the requirements of the Code. He considers the situation to be similar to that permitted by Sentence 220.127.116.11.(1) which deals with skylights in roofs which have windows in another fire compartment overlooking them. As the addition is sprinklered and has no skylights he feels it is a safer situation than that permitted by Sentence 18.104.22.168.(1).
Building Official's Position
The building official maintains that Sentence 22.214.171.124.(6) prohibits the installation of fire rated window assemblies in a firewall. He also provides evidence in the form of an Ontario Building Materials Evaluation Ruling that prohibited sprinklered glazing assemblies in firewalls.
Appeal Board Decision #1253
The Board understands that the exterior wall of the existing building has been accepted by the building official, on an equivalency basis, as a 2 hour firewall. It is the determination of the Board that unprotected openings are not permitted in a firewall. All openings must be protected by closures with a fire protection rating which in this case would be 1-1/2 hours. There is also a temperature rise limitation set in Article 126.96.36.199. for both doors and glazing in fire separations, including firewalls. Column 5 of Table 3.1.6.B. shows the maximum allowable area of glazing in a firewall to be 0 cm2.
George R. Humphrey, Chair