About this chapter: Chapter 26 contains general requirements that could apply to Chapters 26 through 33. Placing such requirements in only one location eliminates code development coordination issues associated with the same requirement in multiple locations. This chapter covers liquid waste disposal requirements, special installation provisions for flood hazard areas and requirements for third-party certification of materials and products that are required to comply with a referenced standard.
Code development reminder: Code change proposals to this chapter will be considered by the IRC—Mechanical/Plumbing Code Development Committee during the 2018 (Group A) Code Development Cycle. See explanation on page iv.
Plumbing fixtures, drains, appurtenances and appliances used to receive or discharge liquid wastes or sewage shall be directly connected to the sanitary drainage system of the building or premises, in accordance with the requirements of this code. This section shall not be construed to prevent indirect waste connections where required by the code.
Exception: Bathtubs, showers, lavatories, clothes washers and laundry trays shall not be required to discharge to the sanitary drainage system where such fixtures discharge to systems complying with Sections P2910 and P2911.
The water-distribution system of any building or premises where plumbing fixtures are installed shall be connected to a public water supply. Where a public water-supply system is not available, or connection to the supply is not feasible, an individual water supply shall be provided. Individual water supplies shall be constructed and installed in accordance with the applicable state and local laws. Where such laws do not address the requirements set forth in NGWA-01, individual water supplies shall comply with NGWA-01 for those requirements not addressed by state and local laws.
Sanitary drainage piping from plumbing fixtures in buildings and sanitary drainage piping systems from premises shall be connected to a public sewer. Where a public sewer is not available, the sanitary drainage piping and systems shall be connected to a private sewage disposal system in compliance with state or local requirements. Where state or local requirements do not exist for private sewage disposal systems, the sanitary drainage piping and systems shall be connected to an approved private sewage disposal system that is in accordance with the International Private Sewage Disposal Code.
Exception: Sanitary drainage piping and systems that convey only the discharge from bathtubs, showers, lavatories, clothes washers and laundry trays shall not be required to connect to a public sewer or to a private sewage disposal system provided that the piping or systems are connected to a system in accordance with Section P2910 or P2911.
In flood hazard areas as established by Table R301.2(1):
Piping shall be supported in accordance with the following:
- Piping shall be supported to ensure alignment and prevent sagging, and allow movement associated with the expansion and contraction of the piping system.
- Piping in the ground shall be laid on a firm bed for its entire length, except where support is otherwise provided.
- Hangers and anchors shall be of sufficient strength to maintain their proportional share of the weight of pipe and contents and of sufficient width to prevent distortion to the pipe. Hangers and strapping shall be of approved material that will not promote galvanic action.
- Where horizontal pipes 4 inches (102 mm) and larger convey drainage or waste, and where a pipe fitting changes the flow direction greater than 45 degrees (0.79 rad), rigid bracing or other rigid support arrangements shall be installed to resist movement of the upstream pipe in the direction of flow. A change of flow direction into a vertical pipe shall not require the upstream pipe to be braced.
- Piping shall be supported at distances not to exceed those indicated in Table P2605.1.
|PIPING MATERIAL||MAXIMUM HORIZONTAL |
|MAXIMUM VERTICAL |
|Copper or copper-alloy pipe||12||10|
|Copper or copper-alloy tubing (11/4 inches in diameter and smaller)||6||10|
|Copper or copper-alloy tubing (11/2 inches in diameter and larger)||10||10|
|Cross-linked polyethylene (PEX) pipe, 1 inch and smaller||2.67 (32 inches)||10b|
|Cross-linked polyethylene (PEX) pipe, 11/4 inch and larger||4||10b|
|Cross-linked polyethylene/aluminum/cross-linked polyethylene (PEX-AL-PEX) pipe||2.67 (32 inches)||4b|
|CPVC pipe or tubing (1 inch in diameter and smaller)||3||10b|
|CPVC pipe or tubing (11/4 inches in diameter and larger)||4||10b|
|PB pipe or tubing||2.67 (32 inches)||4|
|Polyethylene of raised temperature (PE-RT) pipe, 1 inch and smaller||2.67 (32 inches)||10b|
|Polyethylene of raised temperature (PE-RT) pipe, 11/4 inch and larger||4||10b|
|Polypropylene (PP) pipe or tubing (1 inch and smaller)||2.67 (32 inches)||10b|
|Polypropylene (PP) pipe or tubing (11/4 inches and larger)||4||10b|
|Stainless steel drainage systems||10||10b|
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
- The maximum horizontal spacing of cast-iron pipe hangers shall be increased to 10 feet where 10-foot lengths of pipe are installed.
- For sizes 2 inches and smaller, a guide shall be installed midway between required vertical supports. Such guides shall prevent pipe movement in a direction perpendicular to the axis of the pipe.
Each length of pipe and each pipe fitting, trap, fixture, material and device utilized in a plumbing system shall bear the identification of the manufacturer and any markings required by the applicable referenced standards. Nipples created from the cutting and threading of approved pipe shall not be required to be identified.
Exception: Where the manufacturer identification cannot be marked on pipe fittings and pipe nipples because of the small size of such fittings, the identification shall be printed on the item packaging or on documentation provided with the item.