CPC · California Plumbing Code

What does the California Plumbing Code apply to?

The California Plumbing Code applies statewide to nearly every plumbing activity on buildings — new construction, alterations, repairs, maintenance, and demolition — and specifically covers plumbing systems (fixtures, appliances, medical gas, private sewage); check **§ 1.1.3** and the Building Code cross‑reference **§ 101.4.3** to determine applicability and whether local/state agency adoption or appendix rules change enforcement.

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Last reviewed: July 6, 2026

What the code requires — 2–4 sentences

The California Plumbing Code (CPC) applies to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal, and demolition of every building or structure — and any appurtenances attached to them — throughout the State of California as stated in § 1.1.3.

In addition, the California Building Code explicitly references that the provisions of the California Plumbing Code apply to the installation, alteration, repair and replacement of plumbing systems (including equipment, appliances, fixtures, fittings and appurtenances), medical gas systems, and private sewage disposal systems — see § 101.4.3.

The single most important rule: the CPC governs virtually every plumbing activity (new work, changes, maintenance, and removal) on buildings in California — and it governs plumbing systems themselves (including medical gas and private sewage systems). § 1.1.3 and § 101.4.3 are the controlling statements.

Requirements in detail

Activities covered (plain-English breakdown)

The CPC lists a set of activities that trigger its requirements. All of the following are covered under § 1.1.3 unless otherwise modified by other provisions or agency jurisdiction: construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal, and demolition.

For plumbing-system-specific scope, the Building Code cross-reference makes clear the CPC covers installation, alteration, repair and replacement of plumbing systems (including equipment, appliances, fixtures, fittings and appurtenances), medical gas systems, and private sewage disposal systems per § 101.4.3.

Decision-relevant dimensions and values

Decision factor What that means for your project Code Reference
Activity type New building work, changes, maintenance, or removal all fall under the CPC § 1.1.3
Plumbing-system work Installation, alteration, repair, or replacement of plumbing systems, fixtures, fittings, appliances and equipment § 101.4.3
Medical gas systems All aspects of medical gas and medical vacuum systems are covered by the CPC § 101.4.3
Private sewage systems Private sewage disposal systems are within CPC scope § 101.4.3
Geographic reach Applies throughout the State of California § 1.1.3
Agency / occupancy exceptions State agencies may regulate certain buildings separately; see state-regulated/ non-state-regulated distinctions § 1.1.3.1 and § 1.1.3.2

Geographic and jurisdictional details

  • The CPC’s scope is statewide: it applies throughout the State of California (bolded above) per § 1.1.3.
  • There is a distinction between non‑state‑regulated and state‑regulated occupancies: where a state agency has jurisdiction, the model code and any adopted state amendments apply to those agency‑regulated buildings as provided in § 1.1.3.1 and § 1.1.3.2.
  • The California Building Code clarifies inter-code references and confirms that the CPC is the controlling code for plumbing-system work through § 101.4.3.

How the CPC interacts with appendices and other parts of Title 24

  • Many appendices are informational or optional unless specifically adopted; check the applicable appendix text and local/state adoption rules (appendices are not automatically mandatory).
  • Where other Parts of Title 24 reference plumbing requirements (for example energy, mechanical, or existing building provisions), the most restrictive requirement or the specifically applicable provision governs per the order-of-precedence rules in the Building Code (see Building Code § 101.6 for conflict resolution).

Exceptions & special cases

  • Appendices are not mandatory unless a state agency or local jurisdiction adopts them. If you rely on an appendix, confirm local adoption.
  • State agencies may adopt or modify provisions for facilities under their authority; such buildings may be enforced by the state agency only within the authority granted by the Legislature (see § 1.1.3.2).
  • The California Building Code contains a separate exception for detached one- and two-family dwellings and townhouses (these may fall under the California Residential Code instead) — check Building Code § 101.2 Exception when a project is a detached dwelling.

Common mistakes

  • Assuming the CPC only applies to new construction. It explicitly covers alteration, repair, maintenance, and removal as well as new construction — all listed in § 1.1.3.
  • Forgetting that plumbing-system work (fixtures, appliances, equipment) is covered even if it’s limited to an existing building’s interior — the Building Code cross-reference in § 101.4.3 makes that explicit.
  • Treating appendices as automatically enforceable — many are optional unless adopted by the Authority Having Jurisdiction.
  • Not checking whether a facility is state‑regulated (different enforcement or amended provisions could apply per § 1.1.3.2).

Worked example — clinic restroom remodel (concrete scenario with numbers)

Scenario: A 2,000 ft² medical clinic (not state‑regulated) will remodel a restroom block and replace four lavatories and two water closets and reroute a waste stack.

  • Why the CPC applies: the work is an alteration and involves installation/repair/replacement of plumbing fixtures and piping, so the CPC applies to the project per § 1.1.3 and the plumbing‑system coverage in § 101.4.3.
  • Permits and plan review: because the work includes replacement and rerouting (not simple clearing of a stoppage), a plumbing permit and construction documents will typically be required under the CPC’s permit/plan submittal rules (see the CPC permit provisions in Chapter 1 — e.g., § 104.0).
  • If the clinic were a state‑regulated facility (e.g., certain state health facilities), then check § 1.1.3.2 for any state agency amendments or enforcement differences.

Related provisions (quick reference)

  • § 1.1.1 — Title/identification of the California Plumbing Code.
  • § 1.1.2 — Purpose (public health, safety, welfare).
  • § 1.1.3 — Scope (primary controlling scope language).
  • § 1.1.3.1 — Non‑state‑regulated buildings and applications.
  • § 1.1.3.2 — State‑regulated buildings and agency enforcement.
  • § 101.4.3 — Building Code cross‑reference: the CPC applies to plumbing systems, medical gas, and private sewage disposal.
  • § 104.0 (and § 104.3.1) — Permits and construction documents required for regulated plumbing work.
  • Appendix applicability notes — many appendices are not mandatory unless adopted.

Code references

Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:

  • CPC § 101.1 High relevance — show source text

    PART 1—SCOPE AND APPLICATION

    SECTION 101—SCOPE AND GENERAL REQUIREMENTS

    [A] 101.1 Title. These regulations shall be known as the Building Code of [ NAME OF JURISDICTION ], hereinafter referred to as “this code.”

    [A] 101.2 Scope. The provisions of this code shall apply to the construction, alteration, relocation, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures.

    Exception: Detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a separate means of egress, and their accessory structures not more than three stories above grade plane in height, shall comply with this code or the California Residential Code .

    [A] 101.2.1 Appendices. Provisions in the appendices shall not apply unless specifically adopted.

    [A] 101.3 Purpose. The purpose of this code is to establish the minimum requirements to provide a reasonable level of safety, health and general welfare through structural strength, means of egress, stability, sanitation, light and ventilation, energy conservation, and for providing a reasonable level of life safety and property protection from the hazards of fire, explosion or dangerous conditions, and to provide a reasonable level of safety to firefighters and emergency responders during emergency operations.

    [A] 101.4 Referenced codes. The other codes specified in Sections 101.4.1 through 101.4.7 and referenced elsewhere in this code shall be considered to be part of the requirements of this code to the prescribed extent of each such reference.

    [A] 101.4.1 Gas. The provisions of the California Plumbing Code and/or the California Mechanical Code shall apply to the installation of gas piping from the point of delivery, gas appliances and related accessories as covered in this code. These requirements apply to gas piping systems extending from the point of delivery to the inlet connections of appliances and the installation and operation of residential and commercial gas appliances and related accessories.

    [A] 101.4.2 Mechanical. The provisions of the California Mechanical Code shall apply to the installation, alterations, repairs and replacement of mechanical systems, including equipment, appliances, fixtures, fittings and appurtenances, including ventilating, heating, cooling, air-conditioning and refrigeration systems, incinerators and other energy-related systems.

    [A] 101.4.3 Plumbing. The provisions of the California Plumbing Code shall apply to the installation, alteration, repair and replacement of plumbing systems, including equipment, appliances, fixtures, fittings and appurtenances, and where connected to a water or sewage system and all aspects of a medical gas system. The provisions of the California Plumbing Code shall apply to private sewage disposal systems.

    [A] 101.4.4 Property maintenance. The provisions of the California Existing Building Code shall apply to existing structures and premises; equipment and facilities; light, ventilation, space heating, sanitation, life and fire safety hazards; responsibilities of owners, operators and occupants; and occupancy of existing premises and structures.

  • CPC § 101.4 High relevance — show source text

    [A] 101.4 Referenced codes. The other codes specified in Sections 101.4.1 through 101.4.7 and referenced elsewhere in this code shall be considered to be part of the requirements of this code to the prescribed extent of each such reference.

    [A] 101.4.1 Gas. The provisions of the California Plumbing Code and/or the California Mechanical Code shall apply to the installation of gas piping from the point of delivery, gas appliances and related accessories as covered in this code. These requirements apply to gas piping systems extending from the point of delivery to the inlet connections of appliances and the installation and operation of residential and commercial gas appliances and related accessories.

    [A] 101.4.2 Mechanical. The provisions of the California Mechanical Code shall apply to the installation, alterations, repairs and replacement of mechanical systems, including equipment, appliances, fixtures, fittings and appurtenances, including ventilating, heating, cooling, air-conditioning and refrigeration systems, incinerators and other energy-related systems.

    [A] 101.4.3 Plumbing. The provisions of the California Plumbing Code shall apply to the installation, alteration, repair and replacement of plumbing systems, including equipment, appliances, fixtures, fittings and appurtenances, and where connected to a water or sewage system and all aspects of a medical gas system. The provisions of the California Plumbing Code shall apply to private sewage disposal systems.

    [A] 101.4.4 Property maintenance. The provisions of the California Existing Building Code shall apply to existing structures and premises; equipment and facilities; light, ventilation, space heating, sanitation, life and fire safety hazards; responsibilities of owners, operators and occupants; and occupancy of existing premises and structures.

    [A] 101.4.5 Fire prevention. The provisions of the California Fire Code shall apply to matters affecting or relating to structures, processes and premises from the hazard of fire and explosion arising from the storage, handling or use of structures, materials or devices; from conditions hazardous to life, property or public welfare in the occupancy of structures or premises; and from the construction, extension, repair, alteration or removal of fire suppression, automatic sprinkler systems and alarm systems or fire hazards in the structure or on the premises from occupancy or operation.

    [A] 101.4.6 Energy. The provisions of the California Energy Code shall apply to all matters governing the design and construction of buildings for energy efficiency.

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    [A] 101.4.7 Existing buildings. The provisions of the California Existing Building Code shall apply to matters governing the repair, alteration, change of occupancy, addition to and relocation of existing buildings.

    [OSHPD 1] The provisions of Chapters 2, 3A, 4A and 5A of the California Existing Building Code shall apply to all matters governing the repairs, alterations, change of occupancy, additions and relocation of existing structures and portions thereof under OSHPD jurisdic- tion. All references to Chapters 3, 4 and 5 of the California Existing Building Code shall be replaced by equivalent provisions in Chapters 3A, 4A and 5A.

  • CPC § 11.0 High relevance — show source text

    11.0 - 1.11.11_|||X|||||||||||||||||||||| |1.13.0||||||||||||||||||||X||||| |Division II - Scope and
    Administration||||||||||||||||||||||||| |101.0||||||||||X|X|X||X|X|||||||||| |102.0||||||||||X|X|X||X|X|||||||||| |103.0||||||||||X|X|X||X|X|||||||||| |104.2 Items 1 & 2||||X|X|||||||||||||||||||| |104.3.1||||||||||X|X|X||X|X|||||||||| |104.4.3.1|X|||||||||||||||||||||||| |105.0||||||||||X|X|X||X|X||||||||||

    This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

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    CHAPTER 1

    ADMINISTRATION

    DIVISION I

    CALIFORNIA ADMINISTRATION

    1.1.0 General.

    1.1.1 Title. These regulations shall be known as the Califor- nia Plumbing Code, may be cited as such and will be referred to herein as “this code.” The California Plumbing Code is Part 5 of thirteen parts of the official compilation and publi- cation of the adoption, amendment, and repeal of plumbing regulations to the California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This part incorporates by adoption the 2024 Uniform Plumb- ing Code of the International Association of Plumbing and Mechanical Officials with necessary California amendments.

    1.1.2 Purpose. The purpose of this code is to establish the minimum requirements to safeguard the public health, safety and general welfare through structural strength, means of egress facilities, stability, access to persons with disabilities, sanitation, adequate lighting and ventilation, and energy con- servation; safety to life and property from fire and other haz- ards attributed to the built environment; and to provide safety to fire fighters and emergency responders during emergency operations.

    1.1.3 Scope. The provisions of this code shall apply to the construction, alteration, movement, enlargement, replace- ment, repair, equipment, use and occupancy, location, main- tenance, removal, and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures throughout the State of California.

  • CPC § 1.1.0 High relevance — show source text

    CHAPTER 1

    ADMINISTRATION

    DIVISION I

    CALIFORNIA ADMINISTRATION

    1.1.0 General.

    1.1.1 Title. These regulations shall be known as the Califor- nia Plumbing Code, may be cited as such and will be referred to herein as “this code.” The California Plumbing Code is Part 5 of thirteen parts of the official compilation and publi- cation of the adoption, amendment, and repeal of plumbing regulations to the California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This part incorporates by adoption the 2024 Uniform Plumb- ing Code of the International Association of Plumbing and Mechanical Officials with necessary California amendments.

    1.1.2 Purpose. The purpose of this code is to establish the minimum requirements to safeguard the public health, safety and general welfare through structural strength, means of egress facilities, stability, access to persons with disabilities, sanitation, adequate lighting and ventilation, and energy con- servation; safety to life and property from fire and other haz- ards attributed to the built environment; and to provide safety to fire fighters and emergency responders during emergency operations.

    1.1.3 Scope. The provisions of this code shall apply to the construction, alteration, movement, enlargement, replace- ment, repair, equipment, use and occupancy, location, main- tenance, removal, and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures throughout the State of California.

    1.1.3.1 Non-State-Regulated Buildings, Structures, and Applications. Except as modified by local ordinance pur- suant to Section 1.1.8, the following standards in the Cal- ifornia Code of Regulations, Title 24, Parts 2, 2.5, 3, 4, 5, 6, 7, 9, 10 and 11 shall apply to all occupancies and applications not regulated by a state agency.

    1.1.3.2 State-Regulated Buildings, Structures, and Applications. The model code, state amendments to the model code, and/or state amendments where there are no relevant model code provisions shall apply to the fol- lowing buildings, structures, and applications regulated by state agencies as specified in Sections 1.2.0 through 1.14.0, except where modified by local ordinance pur- suant to Section 1.1.8. When adopted by a state agency, the provisions of this code shall be enforced by the appro- priate enforcing agency, but only to the extent of author- ity granted to such agency by the state Legislature.

    Note: See “How to Distinguish Between Model Code Language and California Amendments” in the front of the code.

    1. State-owned buildings, including buildings con- structed by the Trustees of the California State Uni- versity, and to the extent permitted by California laws, buildings designed and constructed by the Regents of the University of California, and regu-

    lated by the Building Standards Commission. See Section 1.2.0 for additional scope provisions.

    2. Section 1.3.0 is reserved for the Board of State and Community Corrections.

  • CPC § 101.5 High relevance — show source text

    101.5 Referenced codes and standards. The codes and standards referenced elsewhere in this code shall be considered part of the requirements of this code to the prescribed extent of each such reference.

    101.5.1 Building. The provisions of the California Building Code, California Residential Code and California Existing Building Code, as applicable, shall apply to the construction, alteration, movement, enlargement, replacement, repair, use and occupancy, location, maintenance, removal and demolition of every structure or any appurtenances connected or attached to such buildings or structures.

    101.5.2 Electrical. The provisions of the California Electrical Code shall apply to the installation of electrical systems, including but not limited to, alterations, repair, replacement, equipment, appliances, fixtures, fittings and appurtenances thereto.

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    101.5.3 Mechanical. The provisions of the California Mechanical Code shall apply to the installation, alterations, repair and replacement of mechanical systems, including equipment, appliances, fixtures, fittings and/or appurtenances, including ventilating, heating, cooling, air-conditioning and refrigeration systems, incinerators and other energy-related systems.

    101.5.4 Plumbing. The provisions of the California Plumbing Code shall apply to the installation, alteration, repair and replacement of plumbing systems, including equipment, appliances, fixtures, fittings and appurtenances where connected to a water or sewage system.

    101.5.5 Fire prevention. The provisions of CCR, Title 19, Division 1 and CCR, Title 24, Part 2 and Part 9 relating to fire and panic safety as adopted by the Office of the State Fire Marshal shall apply to all structures, processes and premises for protection from the hazard of fire, panic and explosion.

    101.5.6 Energy. The provisions of the California Energy Code shall apply to the minimum design and construction of buildings for energy efficiency.

    101.6 Order of precedence and use.

    101.6.1 Differences. In the event of any differences between these building standards and the standard reference documents, the text of these building standards shall govern. In the event a local amendment to this code results in differences between these building standards and the amendment, the text of the amendment shall govern.

    101.6.2 Specific provision. Where a specific provision varies from a general provision, the specific provision shall apply.

    101.6.3 Conflicts. When the requirements of this code conflict with the requirements of any other part of the California Building Standards Code, Title 24, the most restrictive requirement shall prevail.

    101.6.4 Explanatory notes. Explanatory material, such as references to websites or other sources where additional information may be found, is included in this code in the form of notes. Notes are informational only and are not enforceable requirements of this code.

    101.7 City, county, or city and county amendments, additions or deletions. This code is intended to set mandatory minimum Green Building Standards and includes optional tiers that may, at the discretion of any city, county, or city and county, be applied.

  • CPC § 312.0 High relevance — show source text

    312.0 Protection of Piping, Materials, and Structures

    314.0 Trenching, Excavation, and Backfill

    701.3 Drainage Fittings

    705.5.1.1 Butt Fusion Joints

    705.5.1.2 Electro-Fusion Joints

    705.5.1.3 Socket-Fusion Joints

    723.0 Building Sewer Test

    TABLE 1

    CLEANOUTS (See Section 4.6.1)

    The following standards from Tables 1701.1 and 1701.2 of the 2024 Uniform Plumbing Code apply.

    Table 1701.1 Standards

    ASTM D2239 Polyethylene (PE) Plastic Pipe (SIDRPR) Based on Controlled Inside Diameter

    ASTM D2683 Socket-Type Polyethylene Fittings for Outside Diameter-Controlled Polyethylene Pipe and Tubing

    ASTM D3261 Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing

    ASTM F714 Polyethylene (PE) Plastic Pipe (DRPR) Based on Outside Diameter

    ASTM F894 Polyethylene (PE) Large Diameter Profile Wall Sewer and Drain Pipe

    ASTM F1055 Electrofusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene and Crosslinked Polyethylene (PEX) Pipe and Tubing

    ASTM F2620 Heat Fusion Joining of Polyethylene Pipe and Fittings

    Table 1701.2 Standards

    ASTM D2657 Heat Fusion Joining of Polyolefin Pipe and Fittings

    IAPMO PS 25 Metallic Fittings for Joining Polyethylene Pipe for Water Service and Yard Piping

    Note: For SI units: 1 inch = 25 mm

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    "The information contained in this appendix is not part of this American National Standard (ANS) and has not been processed in accordance with ANSI's requirements for an ANS. As such, this appendix may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard."

    The following IAPMO Installation Standard is included here for the convenience of the users of the Uniform Plumbing Code. It is not considered as a part of the Uniform Plumbing Code unless formally adopted as such. This Installation Standard is an independent, stand-alone document published by the International Association of Plumbing and Mechanical Officials and is printed herein by the expressed written permission of IAPMO.

    INSTALLATION STANDARD FOR PEX TUBING SYSTEMS

    FOR HOT- AND COLD-WATER DISTRIBUTION

    IAPMO IS 31-2022

    The provisions contained in this appendix are not mandatory unless specifically adopted by a state agency, or referenced in the adopting ordinance.

    1 Scope

    1.1 General

    1.1.1 This Standard specifies requirements for the installation of SDR 9 CTS crosslinked polyethylene (PEX) tubing and fittings, including cold-expansion, crimp, press, and mechanical compression fittings, intended for hot- and cold-water distribution systems within buildings.

    1.1.2 This Standards applies to

  • CPC § 29.3 High relevance — show source text

    Exceptions:

    (1) Water heaters installed in individual dwelling units.

    (2) Individual gas water heaters with input capacity not greater than 100 000 Btu/h (29.3 kW). [ASHRAE 90.1:7.5.3] L 503.4.4 Heat Recovery for Service Water Heating. Condenser heat recovery systems shall be installed for heating or preheating of service hot water provided all of the following are true:

    (1) The facility operates 24 hours a day.

    (2) The total installed heat rejection capacity of the water-cooled systems exceeds 6 000 000 Btu/h (1758 kW) of heat rejection.

    (3) The design service water-heating load exceeds 1 000 000 Btu/h (293 kW). [ASHRAE 90.1:6.5.6.2.1]

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    APPENDIX L

    L 503.4.5 Capacity. The required heat recovery system shall have the capacity to provide the smaller of:

    (1) Sixty percent of the peak heat-rejection load at design conditions or

    (2) Preheat of the peak service hot-water draw to 85°F (29°C).

    Exceptions:

    (1) Facilities that employ condenser heat recovery for space heating with a heat recovery design exceeding 30 percent of the peak water-cooled condenser load at design conditions.

    (2) Facilities that provide 60 percent of their service water heating from onsite renewable energy or siterecovered energy or from other sources. [ASHRAE 90.1:6.5.6.2.2] L 503.5 Submittals. The Authority Having Jurisdiction shall require submittal of compliance documentation and supplemental information in accordance with Section 104.3.1 of this code.

    L 504.0 Solar Water Heating Systems.

    L 504.1 General. The erection, installation, alteration, addition to, use or maintenance of solar water heating systems shall be in accordance with this section and the Uniform Solar Energy and Hydronics Code.

    L 504.2 Annual Inspection and Maintenance. Solar energy systems that utilize a heat transfer fluid shall annually be inspected unless inspections are required on a more frequent basis by the solar energy system manufacturer.

    L 505.0 Hard Water.

    L 505.1 Softening and Treatment. Where water has a hardness equal to or exceeding 10 gr/gal (171 mg/L) measured as total calcium carbonate equivalents, the water supply line to water heating equipment and the circuit of boilers shall be softened or treated to prevent accumulation of limescale and consequent reduction in energy efficiency.

    L 506.0 Drain Water Heat Exchangers. L 506.1 General. Drain water heat exchangers shall comply with IAPMO PS 92. The heat exchanger shall be accessible.

  • CPC § 4.1 High relevance — show source text
    • 100°F
      (16°C-38°C)|1 h|6 h|2 h|12 h|6 h|24 h| |40°F-60°F
      (4°C-16°C)|2 h|12 h|4 h|24 h|12 h|48 h| |10°F- 40°F
      (-12°C+4°C)|8 h|48 h|16 h|96 h|48 h|8 days| |*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|*If gaps or loose fits are encountered in the system, double these cure times.|

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    IS 33

    FIGURE 1

    LOCATION OF THRUST BLOCKS (STANDARD AND METRIC COMBINED) A COMPARISON OF THRUST-BLOCK AREAS (See Section 4.1)

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    IS 33

    FIGURE 2

    THRUST BLOCK BEARING AREA (See Section 5.2.2)

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    IS 33

    Uniform Plumbing Code References for Ductile Iron and PVC Pressure Building Supply and Exterior Cold-Water Piping

    The following sections of the 2024 Uniform Plumbing Code apply to ductile iron and PVC pressure building supply and exterior cold-water piping.

    Chapter 3 General Regulations

    309.0 Workmanship

    312.0 Protection of Piping, Materials, and Struc tures

    313.0 Hangers, Supports, and Anchors

    314.0 Trenching, Excavation, and Backfill

    Chapter 6 Water Supply and Distribution

    604.0 Materials (water piping)

    Table 604.1 Materials for Building Supply and Water Distribution Piping and Fittings

    605.4 Ductile Iron Pipe and Joints

    605.12 PVC Plastic Pipe and Joints

    605.16.2 Plastic Pipe to Other Materials

    609.0 Installation, Testing, Unions, and Location

    Abbreviations

    IAPMO International Association of Plumbing and Mechanical Officials

    UPC Uniform Plumbing Code published by IAPMO

    AWWA American Water Works Association

    CSA Canadian Standards Association

    Applicable Standards.

    ASME B16.4 Gray Iron Threaded Fittings Classes 125 and 250

    ASTM D1785 Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120

    ASTM D2241 Poly (Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series)

  • CPC § 1.11.0. High relevance — show source text

    This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

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    APPENDIX C

    ALTERNATE PLUMBING SYSTEMS

    The provisions contained in this appendix are not mandatory unless specifically adopted by a state agency, or referenced in the adopting ordinance.

    C 101.0 General.

    C 101.1 Applicability. The intent of this appendix is to provide clarification of procedures for the design and approval of engineered plumbing systems, alternate materials, and equipment not specifically covered in other parts of the code. C 101.2 Provisions. The provisions of this appendix apply to the design, installation, and inspection of an engineered plumbing system, alternate material, and equipment. C 101.3 Authority Having Jurisdiction. The Authority Having Jurisdiction has the right to require descriptive details of an engineered plumbing system, alternate material, or equipment including pertinent technical data to be filed. C 101.4 Standards and Specifications. Components, materials, and equipment shall comply with standards and specifications listed in Chapter 17 of this code and other national consensus standards applicable to plumbing systems and materials.

    C 101.5 Alternate Materials and Equipment. Where such standards and specifications are not available, alternate materials and equipment shall be approved in accordance with the provisions of Section 301.3 of this code.

    C 201.0 Definitions.

    C 201.1 General. For the purpose of this appendix, the following definitions shall apply: Branch Interval. A length of soil or waste stack corresponding in general to a story height, but in no case less than 8 feet (2438 mm), within which the horizontal branches from one floor or story of the building are connected to the stack. Engineered Plumbing System. A system designed for a specific building project with drawings and specifications indicating plumbing materials to be installed, all as prepared by a registered design professional.

    C 301.0 Engineered Plumbing Systems. C 301.1 Inspection and Installation. In other than oneand two-family dwellings, the designer of the system is to provide periodic inspection of the installation on a schedule approved by the Authority Having Jurisdiction. Prior to the final approval, the designer shall verify to the Authority Having Jurisdiction that the installation is in accordance with the approved plans, specifications, and data and such amendments to it. The designer shall certify to the Authority Having Jurisdiction that the installation is in accordance with the applicable engineered design criteria. C 301.2 Owner Information. The designer of the system shall provide the building owner with information concerning the system, considerations applicable for subsequent modifications to the system, and maintenance requirements as applicable.

    C 302.0 Water Heat Exchangers. C 302.1 Protection from Contamination. Heat exchangers used for heat transfer, heat recovery, or solar heating shall protect the potable water system from being contaminated by the heat-transfer medium.

  • CPC § 26-2019 High relevance — show source text

    POLYETHYLENE (PE) PIPE FOR SEWER LATERALS

    IAPMO IS 26-2019 [e4]

    The provisions contained in this appendix are not mandatory unless specifically adopted by a state agency, or referenced in the adopting ordinance.

    1 Scope

    1.1 General

    This standard shall govern the trenchless installation of polyethylene (PE) pipe for use in sanitary and storm sewers. The installed pipe shall comply with the requirements of the Uniform Plumbing Code (UPC [TM] ) published by the International Association of Plumbing and Mechanical Officials (IAPMO) as to grade and connections to existing pipe and shall also comply with this standard. This standard specifies requirements for the installation of the trenchless insertion of polyethylene (PE) pipe for use in sanitary and storm sewers. 1.2 Terminology

    In this Standard,

    (a) “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy to comply with the Standard;

    (b) “should” is used to express a recommendation, but not a requirement;

    (c) “may” is used to express an option or something permissible within the scope of the Standard; and

    (d) “can” is used to express a possibility or a capability.

    Notes accompanying sections of the Standard do not specify requirements or alternative requirements; their purpose is to separate explanatory or informative material from the text. Notes to tables and figures are considered part of the table or figure and can be written as requirements.

    2 Reference Publications

    This Standard refers to the following publications, and where such reference is made, it shall be to the current edition of those publications, including all amendments published thereto.

    ASTM International

    ASTM D3261

    Standard Specification for Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing

    ASTM F714

    Standard Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Outside Diameter

    ASTM F894

    Standard Specification for Polyethylene (PE) Large Diameter Profile Wall Sewer and Drain Pipe

    ASTM F1055

    Standard Specification for Electrofusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene and Crosslinked Polyethylene (PEX) Pipe and Tubing

    ASTM F2620

    Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings

    3 Abbreviations

    The following abbreviations apply in this Standard:

    PE — Polyethylene

    HDPE — High Density Polyethylene

    4 General

    4.1 Product Requirements

    Polyethylene (PE) sewer pipe or tubing and fitting joining methods shall be installed in accordance

    2025 CALIFORNIA PLUMBING CODE 451

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    IS 26

    with the manufacturer’s installation instructions and comply with ASTM F714, ASTM F894 the applicable nationally recognized standard.

    4.2 HDPE Materials

    HDPE Extra High Molecular Weight 3408 SDR 17 Pipe Socket-Type PE Fittings for Outside Diameter Controlled.

  • CPC § 4.6 High relevance — show source text

    Considerations are soil density; clearance from obstacles, utilities, and structures; location of bends, and water service locations. Excavations and shoring shall be in accordance with jurisdictional safety requirements. (c) Set Up Fuse the proper length of polyethylene pipe in accordance with ASTM F2620, or ASTM D3261 and fuse the end to a small length that is attached to the pulling head. A rod pusher cable is pushed through the damaged host pipe and attached to the pulling cable, which is then drawn through the pipe. The clevis end of the cable is attached to the pulling head. The pulling equipment is then set up according to the manufacturer’s instructions.

    (d) Pulling Pull the pulling head through. Once the pull is done, complete the connection to the existing piping.

    4.6 Cleanouts

    4.6.1 Plug Each cleanout fitting for cast-iron pipe shall consist of a cast-iron or brass body and an approved plug. Each cleanout for galvanized wrought-iron, galvanized steel, copper, or brass pipe shall consist of a brass plug as specified in Table 1, or a standard weight brass cap, or an approved ABS or PVC plastic plug, or an approved stainless-steel cleanout or plug. Plugs shall have raised square heads or approved countersunk rectangular slots. 4.6.2 Approved Each cleanout fitting and each cleanout plug, or cap shall be of an approved type.

    452 2025 CALIFORNIA PLUMBING CODE

    ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

    IS 26

    4.6.3 Watertight and Gastight

    Cleanouts shall be designed to be watertight and gastight.

    5 Testing and Inspection Requirements

    5.1 Media

    The piping of the building sewer shall be tested with water. The Authority Having Jurisdiction shall be permitted to require the removal of cleanouts, etc., to ascertain whether the pressure has reached all parts of the system.

    5.2 Water Test

    The system shall be tested by plugging the end of the building sewer at its points of connection to the public sewer or private sewage disposal system and completely filling the building sewer with water from the lowest to the highest point thereof.

    5.3 Inspections

    The completed piping shall be internally inspected by camera unless waived by the Administrative Authority.

    TABLE 1

    CLEANOUTS (See Section 4.6.1)

    NPS SIZE OF CLEANOUT
    (inches)    		 THREADS PER INCH
    1.5 1.5 11.5


    2    		 1.5 11.5


    2.5    		 2.5 8

    3    		 2.5 8

    4 & larger    		 3.5 8

    Note: For SI units: 1 inch = 25 mm

    Uniform Plumbing Code References

    The following sections of the 2024 Uniform Plumbing Code apply.

    105.2 Required Inspections

    105.2.2 Other Inspections

    105.3 Testing of Systems

    301.2 Minimum Standards

    309.0 Workmanship

    312.0 Protection of Piping, Materials, and Structures

  • CPC § 1008.1 High relevance — show source text

    SECTION 1008—MECHANICAL

    1008.1 Mechanical requirements. Where the occupancy of an existing building or part of an existing building is changed such that the new occupancy is subject to different kitchen exhaust requirements or to increased mechanical ventilation requirements in accordance with the California Mechanical Code, the new occupancy shall comply with the respective California Mechanical Code provisions.

    SECTION 1009—PLUMBING

    1009.1 Increased demand. Where the occupancy of an existing building or part of an existing building is changed such that the new occupancy is subject to increased or different plumbing fixture requirements or to increased water supply requirements in accor

    10-4 2025 CALIFORNIA EXISTING BUILDING CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    CHANGE OF OCCUPANCY

    dance with the California Plumbing Code, the new occupancy shall comply with the intent of the respective California Plumbing Code provisions.

    Exception: Only where the occupant load of the story is increased by more than 20 percent, plumbing fixtures for the story shall be provided in quantities specified in the California Plumbing Code based on the increased occupant load.

    1009.2 Food-handling occupancies. If the new occupancy is a food-handling establishment, all existing sanitary waste lines above the food or drink preparation or storage areas shall be panned or otherwise protected to prevent leaking pipes or condensation on pipes from contaminating food or drink. New drainage lines shall not be installed above such areas and shall be protected in accordance with the California Plumbing Code .

    1009.3 Interceptor required. If the new occupancy will produce grease or oil-laden wastes, interceptors shall be provided as required in the California Plumbing Code .

    1009.4 Chemical wastes. If the new occupancy will produce chemical wastes, the following shall apply:

    1. If the existing piping is not compatible with the chemical waste, the waste shall be neutralized prior to entering the drainage system or the piping shall be changed to a compatible material.
    2. Chemical waste shall not discharge to a public sewer system without the approval of the sewage authority.

    SECTION 1010—OTHER REQUIREMENTS

    1010.1 Light and ventilation. Light and ventilation shall comply with the requirements of the California Building Code for the new

    occupancy.

    SECTION 1011—CHANGE OF OCCUPANCY CLASSIFICATION

    1011.1 General. The provisions of this section shall apply to buildings or portions thereof undergoing a change of occupancy classification. This includes a change of occupancy classification within a group as well as a change of occupancy classification from one group to a different group. The provisions of this section shall also apply where there is a change of occupancy within a building or portion thereof and there is a different fire protection system threshold requirement in Chapter 9 of the current California Building Code than exists in the current building or space. Such buildings shall also comply with Sections 1002 through 1010 of this code.

    1011.2 Fire protection systems. Fire protection systems shall be provided in accordance with Sections 1011.2.1 and 1011.2.2.

Frequently asked questions

Who enforces the CPC for a project on a state-owned building?

When a state agency regulates a building, the CPC (including model code and state amendments) applies as adopted by that agency and is enforced by the appropriate enforcing agency to the extent authorized by the Legislature (see § 1.1.3.2).

Does the CPC cover medical gas systems in hospitals and clinics?

Yes — the Building Code cross‑reference states that the CPC provisions apply to all aspects of a medical gas system, so medical gas installation, alteration, repair and replacement fall under the CPC (see § 101.4.3).

Are CPC appendices automatically enforceable?

No. Most appendices are optional and are enforceable only when specifically adopted by a state agency or local jurisdiction — check the specific appendix adoption language.

If I’m only repairing a leaking pipe, do I need a permit?

Minor repairs such as stopping leaks or clearing stoppages can be exempt, but replacement or rearrangement that constitutes new work is typically not exempt — see the CPC permit and exempt‑work language in § 104.0.

Does the CPC apply to private sewage disposal (septic) systems?

Yes. The Building Code expressly states the California Plumbing Code applies to private sewage disposal systems under § 101.4.3.

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