BCAB #1043 - Access Covers for Expansion Joints in DWV Pipe, Article 3.3.9., B.C. Plumbing Code
February 6, 1989
Re: Access Covers for Expansion Joints in DWV Pipe, Article 3.3.9., B.C. Plumbing Code
With reference to your letter of November 9, 1988, regarding access covers at expansion joints in DWV pipe.
Article 3.3.9. of the Plumbing Code requires expansion joints, where necessary, to accommodate expansion and contraction. There is no mandatory requirement for access covers at such locations, although this is suggested in the Appendix, when plastic DWV pipe is used.
We do not consider access to be necessary in all situations, this would depend on the method used to deal with the pipe movement. The issue is basically whether or not the actual pipe, or the installation design, is capable of accommodating movement, without the provision of a special mechanical joint.
In the case of metal pipe, having a degree of flexibility, a non-mechanical device such as an expansion loop or offset, may adequately provide for movement, and in this type of situation we would not consider provision for access to be mandatory. On the other hand, if the method used involved something such as slip, incorporating an elastomeric seal, or other similar mechanical feature, we feel that there is the possibility of failure in a shorter period than can reasonably be anticipated for the pipe; under these circumstances we would consider access to be necessary, and if the installation was concealed, this would entail the provision of an access cover.
We cannot be more precise on this issue, it is of necessity a judgement to be made by the authority having jurisdiction, based on the specific type of joint used, within the general principles provided above. For rigid plastic pipe not incorporating the offset indicated in the Appendix, we know of no satisfactory joint other than a mechanical slip-type, and if such a joint is used in the project under review, then access, possibly with an access cover, would be necessary.
J.C. Currie, Chair