On Jan. 3, 2017, ASA submitted public comments to generate the 2018 edition of the Uniform Plumbing Code (UPC) and the 2018 Uniform Mechanical Code (UMC). The public comments submitted were discussed and reviewed by the ASA Codes and Standards (C&S) committee during a teleconference meeting on
Nov. 7, 2016. The C&S committee is composed of experts in the HVAC, hydronics, plumbing and PVF industry. Members of the committee range from manufacturers to distributors located throughout the United States. One of the major issues discussed by the C&S committee relates to the sizing of the trap and trap arm for single- and multi-head standing showers. The current 2015 UPC (Table 702.1) requires a minimum 2 in. for the trap and trap-arm for single- or multi-head showers.
During the 2015 proposal meeting held in Denver, the UPC Technical Committee discussed and reviewed proposals submitted to the 2015 edition of the UPC. One of the proposals submitted revises the current requirement of 2 in. to 1 1/2 in. for the trap and trap-arm size for standing showers. The proposal achieved the necessary majority affirmative votes during the Technical Committee meeting but failed to achieve the necessary 2/3 affirmative during official balloting. There were arguments made by both sides.