The International Plumbing Code® (IPC®) establishes minimum requirements for plumbing systems using prescriptive and performance-related provisions. It is founded on broad-based principles that make possible the use of new materials and new plumbing designs. This 2018 edition is fully compatible with all of the International Codes® (I-Codes®) published by the International Code Council® (ICC®), including the International Building Code®, International Energy Conservation Code®, International Existing Building Code®, International Fire Code®, International Fuel Gas Code®, International Green Construction Code®, International Mechanical Code®, International Private Sewage Disposal Code®, International Property Maintenance Code®, International Residential Code®, International Swimming Pool and Spa Code®, International Wildland-Urban Interface Code®, International Zoning Code® and International Code Council Performance Code®.

    The I-Codes, including this International Plumbing Code, are used in a variety of ways in both the public and private sectors. Most industry professionals are familiar with the I-Codes as the basis of laws and regulations in communities across the U.S. and in other countries. However, the impact of the codes extends well beyond the regulatory arena, as they are used in a variety of nonregulatory settings, including:

    • • Voluntary compliance programs such as those promoting sustainability, energy efficiency and disaster resistance.

    • • The insurance industry, to estimate and manage risk, and as a tool in underwriting and rate decisions.

    • • Certification and credentialing of individuals involved in the fields of building design, construction and safety.

    • • Certification of building and construction-related products.

    • • U.S. federal agencies, to guide construction in an array of government-owned properties.

    • • Facilities management.

    • • “Best practices” benchmarks for designers and builders, including those who are engaged in projects in jurisdictions that do not have a formal regulatory system or a governmental enforcement mechanism.

    • • College, university and professional school textbooks and curricula.

    • • Reference works related to building design and construction.

    In addition to the codes themselves, the code development process brings together building professionals on a regular basis. It provides an international forum for discussion and deliberation about building design, construction methods, safety, performance requirements, technological advances and innovative products.


    This 2018 edition presents the code as originally issued, with changes reflected in the 2003 through 2015 editions and with further changes approved by the ICC Code Development Process through 2017. A new edition such as this is promulgated every 3 years.

    This code is founded on principles intended to establish provisions consistent with the scope of a plumbing code that adequately protects public health, safety and welfare; provisions that do not unnecessarily increase construction costs; provisions that do not restrict the use of new materials, products or methods of construction; and provisions that do not give preferential treatment to particular types or classes of materials, products or methods of construction.


    The International Plumbing Code is kept up to date through the review of proposed changes submitted by code enforcement officials, industry representatives, design professionals and other interested parties. Proposed changes are carefully considered through an open code development process in which all interested and affected parties may participate.

    The ICC Code Development Process reflects principles of openness, transparency, balance, due process and consensus, the principles embodied in OMB Circular A-119, which governs the federal government’s use of private-sector standards. The ICC process is open to anyone; there is no cost to participate, and people can participate without travel cost through the ICC’s cloud-based app, cdp Access®. A broad cross section of interests are represented in the ICC Code Development Process. The codes, which are updated regularly, include safeguards that allow for emergency action when required for health and safety reasons.

    In order to ensure that organizations with a direct and material interest in the codes have a voice in the process, the ICC has developed partnerships with key industry segments that support the ICC’s important public safety mission. Some code development committee members were nominated by the following industry partners and approved by the ICC Board:

    • American Institute of Architects (AIA)

    • American Society of Plumbing Engineers (ASPE)

    • National Association of Home Builders (NAHB)

    • Plumbing Heating and Cooling Contractors (PHCC)

    The Code Development Committees evaluate and make recommendations regarding proposed changes to the codes. Their recommendations are then subject to public comment and council-wide votes. The ICC’s governmental members—public safety officials who have no financial or business interest in the outcome—cast the final votes on proposed changes.

    The contents of this work are subject to change through the code development cycles and by any governmental entity that enacts the code into law. For more information regarding the code development process, contact the Codes and Standards Development Department of the International Code Council.

    While the I-Code development procedure is thorough and comprehensive, the ICC, its members and those participating in the development of the codes disclaim any liability resulting from the publication or use of the I-Codes, or from compliance or noncompliance with their provisions. The ICC does not have the power or authority to police or enforce compliance with the contents of this code.

    Code Development Committee Responsibilities(Letter Designations in Front of Section Numbers)

    In each code development cycle, proposed changes to the code are considered at the Committee Action Hearings by the International Plumbing Code Development Committee, whose action constitutes a recommendation to the voting membership for final action on the proposed change. Proposed changes to a code section that has a number beginning with a letter in brackets are considered by a different code development committee. For example, proposed changes to code sections that have [BS] in front of them (e.g., [BS] 309.2) are considered by the IBC—Structural Code Development Committee at the code development hearings.

    The bracketed letter designations for committees responsible for portions of this code are as follows:

    = Administrative Code Development Committee;
    = IBC—Egress Code Development Committee;
    = IBC—General Code Development Committee;
    = IBC—Structural Code Development Committee;
    = International Energy Conservation Code Development Committee;
    = International Fire Code Development Committee; and
    = International Mechanical Code Development Committee.

    For the development of the 2021 edition of the I-Codes, there will be two groups of code development committees and they will meet in separate years. Note that these are tentative groupings.

    Group A Codes (Heard in 2018, Code Change Proposals Deadline: January 8, 2018)Group B Codes (Heard in 2019, Code Change Proposals Deadline: January 7, 2019)
    International Building Code – Egress (Chapters 10, 11, Appendix E) – Fire Safety (Chapters 7, 8, 9, 14, 26) – General (Chapters 26, 12, 2733, Appendices A, B, C, D, K, N) Administrative Provisions (Chapter 1 of all codes except IECC, IRC and IgCC, administra-tive updates to currently referenced stan-dards, and designated definitions)
    International Fire CodeInternational Building Code– Structural(Chapters 15-25, Appendices F, G,H, I, J, L, M)
    International Fuel Gas CodeInternational Existing Building Code
    International Mechanical CodeInternational Energy Conservation Code—Commercial
    International Plumbing CodeInternational Energy Conservation Code–Residential– IECC—Residential – IRC—Energy (Chapter 11)
    International Property Maintenance CodeInternational Green Construction Code(Chapter 1)
    International Private Sewage Disposal CodeInternational Residential Code – IRC—Building (Chapters 110,Appendices E, F, H, J, K, L, M, O, Q, R, S, T)
    International Residential Code– IRC — Mechanical (Chapters 1223) – IRC — Plumbing (Chapters 2533, Appendices G, I, N, P)
    International Swimming Pool and Spa Code
    International Wildland-Urban Interface Code
    International Zoning Code
    Note: Proposed changes to the ICC Performance Code will be heard by the code development committee noted in brackets [ ] in the text of the ICC Performance Code.

    Code change proposals submitted for code sections that have a letter designation in front of them will be heard by the respective committee responsible for such code sections. Because different committees hold Committee Action Hearings in different years, proposals for the IPC will be heard by committees in both the 2018 (Group A) and the 2019 (Group B) code development cycles.

    For instance, every section of Chapter 1 of this code is designated as the responsibility of the Administrative Code Development Committee, which is part of the Group B portion of the hearings. This committee will hold its Committee Action Hearings in 2019 to consider code change proposals for Chapter 1 of all I-Codes except the International Energy Conservation Code, International Residential Code and International Green Construction Code. Therefore, any proposals received for Chapter 1 of this code will be assigned to the Administrative Code Development Committee for consideration in 2019.

    It is very important that anyone submitting code change proposals understands which code development committee is responsible for the section of the code that is the subject of the code change proposal. For further information on the Code Development Committee responsibilities, please visit the ICC website at www.iccsafe.org/scoping.

    Marginal Markings

    Solid vertical lines in the margins within the body of the code indicate a technical change from the requirements of the 2015 edition. Deletion indicators in the form of an arrow (https://cdn-codes.iccsafe.org/bundles/document/new_document_images/991/Arrow.jpg) are provided in the margin where an entire section, paragraph, exception or table has been deleted or an item in a list of items or a table has been deleted.

    A single asterisk [*] placed in the margin indicates that text or a table has been relocated within the code. A double asterisk [**] placed in the margin indicates that the text or table immediately following it has been relocated there from elsewhere in the code. The following table indicates such relocations in the 2018 edition of the International Plumbing Code.


    Coordination of the International Codes

    The coordination of technical provisions is one of the strengths of the ICC family of model codes. The codes can be used as a complete set of complementary documents, which will provide users with full integration and coordination of technical provisions. Individual codes can also be used in subsets or as stand-alone documents. To make sure that each individual code is as complete as possible, some technical provisions that are relevant to more than one subject area are duplicated in some of the model codes. This allows users maximum flexibility in their application of the I-Codes.

    Italicized Terms

    Words and terms defined in Chapter 2, Definitions, are italicized where they appear in code text and the Chapter 2 definition applies. Where such words and terms are not italicized, common-use definitions apply. The words and terms selected have code-specific definitions that the user should read carefully to facilitate better understanding of the code.


    The International Code Council maintains a copyright in all of its codes and standards. Maintaining copyright allows the ICC to fund its mission through sales of books, in both print and electronic formats. The ICC welcomes adoption of its codes by jurisdictions that recognize and acknowledge the ICC’s copyright in the code, and further acknowledge the substantial shared value of the public/private partnership for code development between jurisdictions and the ICC.

    The ICC also recognizes the need for jurisdictions to make laws available to the public. All I-Codes and I-Standards, along with the laws of many jurisdictions, are available for free in a nondownloadable form on the ICC’s website. Jurisdictions should contact the ICC at adoptions@iccsafe.org to learn how to adopt and distribute laws based on the International Plumbing Code in a manner that provides necessary access, while maintaining the ICC’s copyright.

    To facilitate adoption, several sections of this code contain blanks for fill-in information that needs to be supplied by the adopting jurisdiction as part of the adoption legislation. For this code, please see:

    Section 101.1. Insert: [NAME OF JURISDICTION]

    Section 106.6.2. Insert: [APPROPRIATE SCHEDULE]

    Section 106.6.3. Insert: [PERCENTAGES IN TWO LOCATIONS]

    Section 108.4. Insert: [OFFENSE, DOLLAR AMOUNT, NUMBER OF DAYS]

    Section 108.5. Insert: [DOLLAR AMOUNT IN TWO LOCATIONS]

    Section 305.4.1. Insert: [NUMBER OF INCHES IN TWO LOCATIONS]

    Section 903.1. Insert: [NUMBER OF INCHES]