Subscribe to our newsletters & stay updated
This is a continuation of a summary of the significant code changes to the 2021 Uniform Plumbing Code (UPC) which is developed and promoted by the International Association of Plumbing and Mechanical Officials.
These code changes will appear in the 2021 edition of the International Plumbing Code. Because it is possible for modifications to be made during the final hearing process and because there were multiple changes made to some code sections, the final edited version may be slightly different than what was in the actual code change proposal. Refer to the 2021 International Plumbing Code for the final version of any code changes.
The proposed new code language is underlined. The text proposed to be deleted is stricken through. The proposed changes are followed by the proponent’s published reason statements, and occasionally by my comments when noted.
Code Change: 2021 UPC Code, Chapter 7, Sanitary Drainage, Section 715.3, Existing Sewers
Add new text as follows:
715.3 Existing Sewers. Replacement of existing building sewer and building storm sewers using trenchless methodology and materials shall be installed in accordance with ASTM F1216, ASTM F2561, ASTM F2599, or ASTM F3240. Cast-iron soil pipes and fittings shall not be repaired or replaced by using this method aboveground or belowground. Replacement using cured-in-place pipe liners shall not be used on collapsed piping or when the existing piping is compromised.
Proponents’ reason statement: The wording was changed to more appropriately reflect the current industry use of "rehabilitation" rather than trenchless, which is included in the title of all appropriate standards. The technology has progressed and many other standards are in use today that are needed to ensure performance and water tightness. In addition, minimal inspection requirements are needed and should be required. Finally, restrictions should be in separate section.
My comments: During the first round of code hearings, this code change was turned down. It was revised and resubmitted with amendments and the comment was modified to keep the existing language in Section 715.3 and add the option of using other standards for cured-in-place methods. Additional substantiation comments at the next round of hearings were “approved as modified.” The following substantiation was printed with the revised code change proposal.
Proponents’ reason statement in comment No. 1: Unfortunately, the committee did not discuss the revision to the original submittal of Item No. 126. While the original submittal was somewhat restrictive, it was not proprietary as patented products and methods are allowed by both IAPMO and ASTM procedures and the product/method covered by these standards is readily available in the marketplace.
This amendment clarifies that we are adding only cured-in-place standards, which all reference the existing cured-in-place standard ASTM F1216 currently required in the code. In addition, the amendment deletes the term "trenchless methodology and materials" as all standards referenced use the term "Rehabilitation" in the title as that is the industry term now used. Finally, the revision adds inspection requirements which are consistent with requirements in ASTM F1216.
Code Change: 2021 UPC Code, Chapter 9, Vents, Section 911.0, Circuit Venting
Revise text as follows:
911.0 Circuit Venting.
911.1 Circuit Vent Permitted. A maximum of eight
fixtures floor-outlet water closets, showers, bathtubs, or floor drains connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain trap arm shall connect horizontally to the horizontal branch being circuit vented in accordance with Table 1002.2. The horizontal branch drain shall be classified as a drain and a vent from the most downstream fixture drain trap arm connection to the most upstream fixture drain trap arm connection to the horizontal branch.
Exception: Back-outlet and wall-hung water closets shall be permitted to be circuit vented provided that no floor-outlet fixtures are connected to the same horizontal branch.
911.1.1 Multiple Circuit-Vented Branches. Circuit-vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall be in accordance with the of this section
911.2 Circuit Vent Size and Connection. The circuit vent size shall be in accordance with Table 703.2 according to the number of circuit vented fixtures connected to the horizontal branch but shall be not less than 2 inches (50 mm) in diameter
and the connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch on the vertical between the two most upstream trap arms. The circuit vent pipe shall not receive the discharge of a soil or waste.
911.2.1 Multiple Circuit Vents. When multiple circuit vents are interconnected according to Section 911.4.1, each individual circuit vent shall be sized according to Section 911.2. The vent pipe connecting each circuit vent shall be sized according to Table 703.2.
911.3 Slope and Size of Horizontal Branch. The slope of the vent section of the horizontal branch drain shall be not more than 1 inch per foot (83.3 mm/m). The entire length of the vented section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. 911.3.1 Size of Multiple Circuit Vent. Multiple circuit vented branches shall be permitted to connect on the same floor level. Each separate circuit-vented horizontal branch that is interconnected shall be sized independently in accordance with Section 911.3. The downstream circuit-vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 911.4 911.3 Relief Vent. A 2-inch (50 mm) relief vent shall be provided for circuit-vented horizontal branches receiving the discharge of four or more water closets and whenconnecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 911.4.1 911.3.1 Connection and Installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain trap arm of the circuit vent. The relief vent shall be installed on the vertical to the horizontal branch. 911.4.2 911.3.2 Fixture Drain or Branch. The relief vent is permitted to be serve asa fixture drain or fixture branch for a fixture located within the same branch interval as the circuit-vented horizontal branch. Fixtures The discharge discharging to a relief vent shall be one or two fixture unit fixtures but shall not exceed a total of 4 fixture units.
911.4 Slope and Size of Horizontal Branch. The vented section of the horizontal branch shall be uniformly sloped and not more than 1 inch per foot (83.3 mm/m). The entire length of the vented section of the horizontal branch shall be sized for the total drainage discharge to the branch according to Table 703.2.
911.4.1 Multiple Circuit-Vented Branches. Circuit-vented horizontal branches are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall be in accordance with Section 9220.127.116.11 and Section 918.104.22.168.
922.214.171.124 Size of Parallel Horizontal Branches. Parallel horizontal circuit vented branches shall be permitted to connect on the same floor level. Each separate circuit-vented horizontal branch that is interconnected shall be sized independently in accordance with Section 911.4.
9126.96.36.199 Size of Continuous Horizontal Branches. Two or more circuit vented systems continuous on the same horizontal branch shall be uniformly sized for the total discharge into the branch.
911.5 Additional Fixtures. Fixtures, other than the circuit-vented fixtures, are permitted to discharge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit-vented fixtures and shall be either individually or common vented.
Code Change: 2021 UPC Code, Chapter 2, Definitions, Circuit Vent
Add new definition as follows:
Circuit Vent. The vent that connects to a horizontal drainage branch and vents two traps to a maximum of eight traps connected into a battery of fixtures.
Proponents’ reason statement in comment No. 1: Because of the public concern that the current code language is confusing and unclear as to the meaning, application and enforcement of circuit venting, increasing the possibility of incorrect and unintended installations. The proposed changes rectify this confusion by adding significant clarity to the provisions of the code, correcting improper terminology, removing uncertain phrases, and by arranging the provisions more suitable to the components of the system.
The revision begins with adding a definition for circuit venting and identifying the number and specific kinds of fixtures allowed for a circuit vent that is not present in the current edition. This will curtail unintended installations. Circuit venting is applied only to specific floor mounted fixtures in battery.
The term fixture drain is improperly used and is corrected with the proper term of trap arm. A reference to Table 1002.2 was needed to limit trap arm length. An exception was added to allow back-outlet water closets commonly used in commercial applications, which are not floor-outlet fixtures.
The rest of the provisions are arranged by components. First, the circuit vent pipe provisions. Second, the relief vent pipe provisions. Third, the horizontal branch provisions. Fourth, additional fixtures connected to the circuit-vented horizontal branch.
The revision adds circuit-vent sizing by referencing Table 703.2. Currently, there is no guidance for circuit vent sizing other than a minimum size of 2 inches. For example, eight public water closets on a circuit-vented horizontal branch are a total of 32 fixture units. Referring to Table 703.2, the vent is required to be three inches rather than two. Without this table reference, there was no guidance to suggest an increase of the circuit vent size.
Furthermore, the provisions allow other than circuit vented fixtures to connect to the circuit vent without indicating how they impact the size of the circuit vent. Therefore, clarity was added to identify only the circuit-vented fixtures used with Table 703.2 to size the circuit vent. Multiple circuit-vented branches are also allowed to connect together without any guidance on how to size the horizontal vent connecting all the individual circuit vents. Hence, a new subsection, 911.2.1 was added to address this omission.
The relief vent can also serve as a fixture drain with a total of four fixture units. This needed restriction since fixtures such as clothes washers, public wash fountains and commercial sinks were not intended to discharge into the relief vent. Therefore, the revision restricts the discharges to one and two fixture unit fixtures.
The horizontal branch provisions needed the most revision. Section 911.3.1 is mistitled since the provisions do not apply to the circuit vent, but to the horizontal branch. Furthermore, the language is confusing and suggests more a parallel application than a continuous application for multiple circuit-vented horizontal branches connecting together.
Therefore, the revision makes a distinction in application of multiple circuit-vented branches — parallel and continuous. The sizing is different for each application. For the parallel application, the circuit-vented horizontal branches are sized independently. For the continuous application, the circuit-vented horizontal branches are uniformly sized for the combined discharge into the branch.
My comments: This code change added some language, struck out some language and added a definition on circuit venting. The resulting language is confusing and did not add much clarification. This change demonstrates the need for a person with English skills and a person with an understanding of the plumbing engineering and fluid dynamics & hydraulics issues associated with plumbing systems to serve as a staff person(s) to review and assist with these code changes from well-intentioned persons that in many cases could use some assistance with English and grammar.
Having a staff position to assist with English and engineering issues with the proponents would make the codes read better overall by having proposed code changes reviewed for proper English and grammar and a review of the proposed language for technical merits. I feel this would make the code change process go much smoother when code change proposals are understandable, unambiguous and technically correct before they get published in the code change proposal monograph.
This code change does not seem to add clarity or improve the code. If anything, it added restrictions and confusion. For example, the definition of a circuit vent gives specific limitations for circuit vents without defining that it is a venting method that allows air to flow in a circuit. Good code language proposals do not put technical code requirements in the definitions. Circuit venting has been used successfully in model codes for many years.
Code Change: 2021 UPC Code, Chapter 11, Storm Drainage, Section 1101.4, Material Uses
Revise text as follows:
Chapter 11 Storm Drainage
1101.4 Material Uses. Pipe, tube, and fittings conveying rainwater shall be of such materials and design as to perform their intended function to the satisfaction of the Authority Having Jurisdiction. Conductors within a vent or shaft shall be of cast-iron, galvanized steel, wrought iron, copper, copper alloy, lead, Schedule 40 ABS DWV, Schedule 40 PVC DWV, stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or other approved materials, and changes in direction shall be in accordance with the requirements of Section 706.0. ABS and PVC DWV piping installations shall be installed in accordance with applicable standards referenced in Table 1701.1 and Chapter 14 “Firestop Protection.” Except for individual single-family dwelling units, materials exposed within ducts or plenums shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50, where tested in accordance with ASTM E84 or UL 723.
These tests shall comply with all requirements of the standards to include the sample size, both for width and length. Plastic pipe shall not be tested filled with water. Plastic piping installed in plenums shall be tested in accordance with all requirements of ASTM E84 or UL723. Mounting methods, supports and sample sizes of materials for testing that are not specified in ASTM E84 or UL 723 shall be prohibited.
Proponents’ reason statement: A growing issue in the plumbing industry is that the ASTM E84 test protocol is being modified to test combustible piping materials. At the direction of plastics manufacturers, test labs will modify mounting methods, supports and test specimen dimensions to achieve results that are in compliance with the 25/50 benchmarks the code requires.
These results are then used to secure a listing by third-party certifiers to serve as proof to code officials of compliance to the flame spread and smoke developed index requirements found in the code.
The question of whether a piping material is in compliance to the flame spread and smoke developed requirements of the code is often further blurred as third-party certifiers provide listings indicating that materials meet the 25/50 requirements using modified test methods. Third-party certifiers disclose this information in their full listing or report, but this is not always easily identified or even accessible to officials.
An inspector seeing ASTM E84 on a pipe would likely assume that it meets the requirement of the code without fully knowing or understanding the restrictions that exist in the listing. In fact, listing agencies assume that the inspector will analyze the listing and make their own determination on compliance. This code change proposal provides notice to the official that simply adding the ASTM E84 or UL 723 marking to the wall of the pipe does not necessarily mean that the product was tested in full compliance with the standard in the manner that the code intends.
A manufacturer has conducted ASTM E84 tests at two different test facilities and found that results below the 25/50 flame spread and smoke developed index are not achievable when performed to the full requirements of ASTM E84. The manufacturer’s testing has shown that CPVC and PVC piping will not pass the ASTM E84 tests without modification of the mounting method, supports or test specimen dimensions.
If the practice of accepting modified test results is allowed to continue, then the requirements of the code will not be achieved. ASTM E84 is a comparison test, and the 25/50 flame spread and smoke developed index is not a requirement of the standard, but of the code itself.
If the 25/50 requirement is too restrictive, then an effort should be made to change the code. If the ASTM E84 test method is flawed, change the standard. However, we can no longer allow the use of modified tests and third-party listings to circumvent the requirements of the code which exist to preserve the health and safety of the public.
My comments: During the code hearings, this subject became a big battle and it seems to have spilled over from an ASTM standard committee that could not resolve an issue in the standard into the code change arena. It was discovered that some manufacturers tried to get these listing requirements included into the ASTM E84 tests for fire flame spread and smoke development with language prohibiting alteration of the mounting requirements in the ASTM E84 fire test tunnel.
The other manufacturers who were lining the wall of the tunnel with their pipe and using mounting clips to do so were not using flat sheets of material as called for in the flame and smoke spread tunnel test. Of course, pipe is round not flat, so some manufacturers cut their pipe in half and mounted them on the wall of the fire and smoke tunnel test where the flat material was supposed to be mounted.
Others simply mounted their pipe side by side and used Unistrut brackets to hold them in place. Some manufacturers pointed out that they require pipe to be mounted more often than the mounting requirements specifically listed in the ASTM E84 test tunnel, and there were other issues where some manufacturers tested their pipe with water in them.
The manufacturers of metal pipe were unsuccessful at getting the standard changed to restrict mounting methods that were favorable to plastic piping manufacturers, so they brought pipe standard test procedures to the codes.
To me, it was a colossal waste of time because horizontal storm drains typically require insulation to prevent condensation from dripping on ceilings and the insulation must meet the 25/50 flame and smoke spread requirements and protect the plastic pipe from sagging, burning or producing toxic smoke.
Many people pointed out this is a pipe testing standard issue and this limitation on requirements for testing of pipes issue does not belong in the codes. It needs to be resolved within the standards work group within the ASTM E 84 standard, or maybe a new standard needs to be developed for testing materials that are not sheet materials.
This is a continuing series covering significant code changes from the 2018 to the 2021 edition of the Uniform Plumbing Code. It will continue next month.