BCAB #1253 - Windows in a Firewall Above a Roof - Sentences and

Last updated on March 24, 2016

June 26, 1991

BCAB #1253

Re: Windows in a Firewall Above a Roof - Sentences and

Project Description

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.

Appellant's Position

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 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

Building Official's Position

The building official maintains that Sentence 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 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