BCAB #1110 - Exposed Wall Openings
December 19, 1989
Re: Exposed Wall Openings
With reference to your letter of November 11, 1989, regarding Sentences 220.127.116.11.(1) and 18.104.22.168.(2).
It may be advantageous if we first deal with Articles 22.214.171.124. and 126.96.36.199., before responding to your specific questions. These two Articles accept the conditional use of wired glass assemblies and glass block in fire separations. We take this to mean that they are not regarded as complete equivalents, but will, subject to certain limitations, provide an acceptable level of protection.
Sentence 188.8.131.52.(2) reinforces the above conclusion, and specifically precludes the use of wired glass or glass blocks to protect openings in any wall with a limiting distance of less than 1.2 m.
Sentence 184.108.40.206.(1) deals with an external wall configuration involving walls meeting at an angle, rather than facing each other. For such a situation the formula provides an equivalent factor to be taken as the limiting distance. However, as it is still dealing with an exterior wall and limiting distance, we consider that Sentence 220.127.116.11.(2) must apply. This would appear to answer both of your questions; within 1.2 m, wired glass and glass blocks are not acceptable; if "Do" is 1.2 m or more, then such assemblies are acceptable, subject to the stated conditions.
J.C. Currie, Chair