BCAB #1110 - Exposed Wall Openings

December 19, 1989

BCAB #1110

Re: Exposed Wall Openings

With reference to your letter of November 11, 1989, regarding Sentences 3.2.3.10.(1) and 3.2.3.4.(2).

It may be advantageous if we first deal with Articles 3.1.6.10. and 3.1.6.11., 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 3.2.3.4.(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 3.2.3.10.(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 3.2.3.4.(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