BCAB #1895

August 18, 2022

Re: Use of Long Sweep 90 degree Elbows in a Sanitary Drainage System

(Long sweep means an elbow fitting whose centre-line radius is equal to or greater than the size of the pipe)  

Project Description

The subject is a sanitary drainage system serving a house with a secondary suite. A 3 inch [76.2 mm] diameter, long sweep, 90 degree elbow, that changes direction of flow from nominal vertical to nominal horizontal, has been installed as part of the sanitary drainage system.

Applicable Code requirements: (BCPC 2018)

2.2.4.3. 90° Elbows

1) Except as permitted in Sentence (2), 90° elbows of 4 inch size or less whose centre-line radius is less than the

size of the pipe shall not be used to join 2 soil-or-waste pipes.

2) For sanitary drainage systems of 4 inch size or less, 90° elbows described in Sentence (1) shall only be permitted

a) to change the direction of piping from horizontal to vertical, in the direction of flow,

b) where a trap arm enters a wall, or

c) to connect trap arms as permitted by Sentence 2.5.6.3.(2).

Decision being appealed (local authority’s position)

The local authority has determined the use of any 90 degree elbow is limited to the conditions described in Sentence 2.2.4.3.(2)., which would limit the change of direction of piping from horizontal to vertical in the direction of flow. In this circumstance, the elbow is installed from vertical to horizontal in the direction of flow.

Appellant's position

The appellant considers the restrictions placed on the use of 90 degree elbows stated in Sentence 2.2.4.3.(2) are limited to 90 degree elbows of 4 inch [101.6 mm] size or less whose centre-line radius is less than the size of the pipe. Further, the appellant considers the use of long sweep 90 degree elbows is not restricted by the Code and can be used anywhere within a sanitary drainage system.

Appeal Board decision #1895

It is the determination of the Board that the restrictions of Sentence 2.2.4.3.(2) do not apply to long sweep elbows.

Reason for decision

The decision is consistent with the BCIC interpretation 06-0017.

Lyle Kuhnert
Chair, Building Code Appeal Board