ICC, IAPMO Continue Talks on Plumbing Code Consolidation

By Carl C. Schultz, P.E., Chief Mechanical Engineer, URS Corporation, Columbus, Ohio January 1, 2006

This coming February in San Antonio, Texas, discussions will continue between the International Code Council (ICC) and the International Assn. of Plumbing and Mechanical Officials (IAPMO) for developing a joint code. Actually, the new code would encompass the Uniform Plumbing Code (UPC), the Uniform Mechanical Code (UMC), the International Plumbing Code (IPC) and the International Mechanical Code (IMC).

The two organizations signed a memorandum of understanding late last year with the goal of a joint code to be issued at the next cycle in 2009. Both organizations, however, are scheduled to issue new editions of their respective plumbing codes this year.

As a mechanical engineer who works in a firm with a national presence, I find it cause for optimism. Anyone who has worked on projects outside one’s region knows valuable time must be spent researching local plumbing regulations. This unpleasant task should ideally take place before commencing with the design, but too often, it involves ordering—and waiting for—code books, not to mention the time it takes to actually get up to speed on the major differences between local codes and the code that we are most familiar with, the IPC.

So code consolidation can be good. The adoption of the International Building Code (IBC) by 45 states, the District of Columbia and 750 local jurisdictions to date has certainly been embraced by the architects in our firm. This makes their job easier, as these designers need only be concerned with what edition of the IBC the local code is based on.

That being said, code consolidation is also likely to throw engineers some nasty curveballs.

For example, the ICC is responsible for numerous codes besides the IBC, including the IPC and the IMC, but also the International Fire Code, a residential plumbing code and a fuel gas code. As a result, those familiar with the UPC could possibly see many sections eliminated, such as those on gas piping, water heater venting and one- and two-family dwellings. This will certainly not alleviate the need for many engineering firms to acquire additional reference materials on these subjects.

There are also some deficiencies in the IPC. For example, the UPC addresses expansion joints on storm piping where temperature variations warrant their use; the IPC does not. In other words, the IPC relies more on other codes and standards, including related ICC documents, whereas the UPC is more self-contained and able to stand on its own.

Furthermore, the IPC falls short in addressing medical gas and vacuum systems. Specifically, many sections have not been fully coordinated with NFPA 99C. On the subject of health care, the IPC also requires two water services for hospitals, while the UPC does not. Additionally, the IPC mandates that the seal in HVAC condensate traps for health-care facilities be maintained with a water supply, something not required by the UPC.

There are any number of differences between the codes. Engineers should keep track of all these contradictions and inconsistencies approaching 2009, as it appears that a combined code is indeed imminent. The IPC, for example, allows engineered vent systems, permitting the designer to reduce the size of the venting system, whereas the UPC does not. The UPC also does not allow the termination of vents through a sidewall as the IPC does. The IPC allows garbage disposals to discharge to grease interceptors, provided there is a solids separator ahead of the trap; the UPC does not permit this, staying consistent with the recommendations of many manufacturers.

Unlike the IPC, the UPC does not permit the use of air-admittance valves. The argument is that they are subject to mechanical failure, are affected by building pressures and do not prevent or relieve overpressurization in the drain and vent system.

Regarding piping, the IPC permits the joining of copper and galvanized steel pipe, which is prohibited under the UPC. As opposed to the IPC, the UPC does not encourage the combination of sanitary and storm systems by including a conversion from fixture units to roof area.

Finally, for those interested in sustainable design, the UPC does not allow gray water recycling systems that permit wastewater from bathtubs, showers and lavatories to be used for flushing water closets and urinals within the same building; the IPC does. The UPC would like this water to be treated by a public agency to specific criteria, and then be approved for use by a public health authority. The IPC permits waterless urinals in its 2006 code, but this technology is not scheduled to be in the 2006 UPC.

Despite these differences, recent history lends cause for hope for consolidation, even progressive change.

IAPMO, which maintains the UPC, has its origins rooted in the local code-enforcement side of the industry, having been started as the Plumbing Inspectors Assn. of Los Angeles in 1926. It has a strong presence on the West Coast, is used by many local jurisdictions across the country—even exclusively by some states. The organization also has a strong labor component. Going into last year’s UPC hearings in Albuquerque, N.M., there was a perception that proposed code changes that could potentially reduce field labor, such as allowing waterless urinals, might be more difficult for this organization to pass.

This, however, proved not to be the case as evidenced by the passage of single-stack venting systems for secondary storm drainage. The system, also known as the “Philadelphia single-stack,” has been used successfully in that city as well as in Europe for many years.

The change allows a third option where overflow can go to scuppers. Independent piping systems for primary and secondary drains that discharge to the outdoors are also allowed. Labor savings are accrued because the primary and overflow drains share a common, oversized piping system that can accommodate twice the amount of rainfall.

The UPC moved this to the code’s Appendix on engineered design. Ironically, the IPC shot down these same changes at its hearings in Detroit last year.