International Plumbing Code 2018


ICC’s highly esteemed code development process brings together building professionals on a regular basis to collaborate on creating changes to ICC codes that ensure public health, safety, and welfare are adequately protected, innovation without unnecessarily increasing construction costs, and equitable enforcement.

The 2024 edition includes several changes designed to promote sustainable plumbing practices. Logical organization and helpful illustrations help readers quickly navigate this code.

General Requirements

The International Plumbing Code 2018 governs the erection, installation, alteration, repair, relocation, replacement, or addition of plumbing systems, as well as the piping fixtures, equipment, and venting drains that connect them. It aims to protect public health, safety, and welfare by guaranteeing minimum requirements are met for these installations; its development involves a broad-based open code development process taking into account local government needs, industry stakeholders, and the general public.

The 2024 International Plumbing Code is currently under development (please view the code development schedule). Anyone can participate by attending public comment hearings or providing comments through ICC’s online web-based system, cdpACCESS. ICC’s governmental members, who serve without financial or business interests, cast final votes on proposed code changes.

The International Plumbing Code is an expansive set of standards adopted by local governments for administering and enforcing laws pertaining to plumbing, heating, ventilation, air conditioning, sanitary drainage, gas piping and appliances, sewage disposal systems, water heaters, and solar thermal water heating. Correlated with other codes produced by ICC, it can form part of a comprehensive building safety code system, regularly updated through an open code development process on a three-year cycle.

Water Heaters

Water heaters provide potable hot water for bathing, washing, and cooking activities in residential dwellings. Hot water is often stored in pressurized tanks that must be protected against explosion by pressure/temperature relief valves – this section addresses their location requirements as well as access requirements.

One of the proposed changes would require installing a pan under each gas-fired water heater, which may impact their popularity among households and may add significantly to the costs of installation of small instantaneous units typically installed under kitchen sinks in homes. A pan of sufficient size must be present under each unit to catch any leaking water, and installing it could significantly add to installation expenses.

Another proposal concerns bathroom temperature ranges for hot and tempered water usage. At present, the code defines minimum hot water temperatures of 110deg F and maximum tempered water temperatures of 85deg F; proponents of change propose increasing these numbers to 120deg F and 115deg F, respectively.

Another proposed amendment would permit the use of stainless steel piping to regulate the temperature of tepid water used in showers, bathtubs, shampoo sinks, eyewashes, and lavatories. While the current code requires ASSE 1071 valves to be used instead, under the proposal, this use would be allowed by using ASSE 1085 valves instead.

Sewage Disposal

The code encompasses all aspects of plumbing facilities. It establishes minimum standards for water, soil, and waste pipe installations, as well as provisions to prevent rodent entry into buildings. Furthermore, the code regulates cast iron soil pipes, identifies products with third-party certification, and specifies inspection requirements for private sewage disposal systems.

Sanitary drainage piping from all plumbing fixtures located within buildings or on-premises must be connected to either the public sewer, if available, or an approved private sewage disposal system that complies with the International Private Sewage Disposal Code. Ash, cinders, rags, oil and grease, insoluble substances, or any wastes that might interfere with the proper operation of building drainage or sewer systems or that might enter public sewers or drinking water storage and distribution networks should not be dumped into such drainage or sewer systems.

The code fosters life-cycle cost savings for home and business owners by decreasing energy utility usage to heat, pump, and treat drinking water. Furthermore, it reduces drought-induced shortages by restricting water usage during drought conditions while simultaneously limiting storm drain discharge of wastewater.


All plumbing fixtures must be appropriately vented to avoid syphonic action and preserve trap seals. Each water closet, lavatory, and fixture drain must be connected directly to a vent; such connections should not fall below the weir of their respective trap.

Buildings over 30 stories above grade must install soil stacks with velocity breaks of two 45-degree breaks per floor for ventilation purposes, along with a relief vent equal to one-half the size of their stack vent. These requirements also apply to wastewater systems within the building.

Vent terminals must be covered to protect them against rain and snow accumulation, which has previously caused problems when venting drainage systems to atmospheric pressure. According to an NBS report that addressed this matter, however, snow accumulation did not significantly hinder vent terminal performance due to heated vapors from indoor plumbing systems thawing out snow accumulation quickly enough for airflow through its vent terminals.

The International Code Council (ICC) oversees its international plumbing code by reviewing any proposed changes submitted by code enforcement officials, industry representatives, and design professionals through an open code development process. This enables local jurisdictions to make necessary modifications in order to protect public health and safety effectively.