BCAB #948 - Combustible Piping, Article 3.1.7.3.

December 10, 1987

BCAB #948

Re: Combustible Piping, Article 3.1.7.3.

With reference to your letter of October 19, 1987, regarding the connections to water closets in a high rise building. Refer also to Appeal No. 947 for some general provisions applicable to this appeal.

Our decisions on the specific questions raised are:

1. This was dealt with under Appeal No. 710, copy attached.

2. This is permitted by Sentence 3.1.7.3.(3) provided the pipe leads directly to a noncombustible water closet. If not, it must comply with the provisions of Clause 3.1.7.3.(2)(a), and must not be located in a vertical shaft.

3. There is no indication that the combustible drain pipe passes through a fire separation, but we will answer the question dealing with both circumstances.

(a) Under Sentence 3.1.7.3.(1) combustible pipe, including the elbow, is permitted provided that no part of the system passes through a fire separation required to have a fire resistance rating. In other words the system is completely contained within the compartment enclosed by the fire separations.

(b) If the pipe does pass through a fire separation it is only acceptable subject to compliance with Sentences 3.1.7.3.(2) to (4).

From these it must be taken that under no circumstances is the pipe permitted in a vertical shaft.

The actual penetration of a fire separation is acceptable subject to the actual assembly being tested to CAN4-S101, as indicated in Clause 3.1.7.3.(2)(a). We have also indicated in another appeal that we regard CAN4-S115 as a later, more acceptable version of this standard.

Penetration of a horizontal fire separation is permitted without testing, provided that the pipe loads directly to a noncombustible water closet, as indicated in Sentence 3.1.7.3.(3).

Pipe is permitted on one side of a vertical fire separation, under Sentence 3.1.7.3.(4). We take this to mean that any actual penetration of the vertical fire separation will be made with noncombustible pipe, in conformance with Article 3.1.7.1.

We consider that compliance with Sentences (2) to (4) of Article 3.1.7.3. exempts a system from the provisions of Sentence 3.1.7.3.(1). In other words, under such circumstances, they permit the use of combustible drain, waste and vent piping, where part of the system penetrates a fire separation required to have a fire resistance rating.

4. The noncombustible waste stack will presumably pass through a horizontal fire separation. From our explanation of Sentence 3.1.7.3.(4) above, we would regard this connection as acceptable provided that the noncombustible waste stack was not located on the same side of the fire separation as the combustible pipe, and the actual penetration of the fire separation was made with noncombustible pipe.

J.C. Currie, Chair