Approved Plumbing Materials and Fixtures Under Wisconsin Code

Wisconsin's plumbing code establishes binding specifications for the materials and fixtures that may be installed in any plumbing system within the state, covering pipe composition, fitting standards, fixture ratings, and the certification bodies whose approval carries regulatory weight. These requirements apply to new construction, remodels, and repair work alike, and noncompliant materials are subject to rejection at inspection. Understanding which materials and fixtures meet Wisconsin's codified standards is foundational to any licensed plumbing project in the state.

Definition and scope

Wisconsin's plumbing material and fixture standards are codified primarily in Wisconsin Administrative Code Chapter SPS 382, which governs plumbing systems in one- and two-family dwellings, and Chapter SPS 384, which addresses commercial and multifamily systems. These chapters specify acceptable pipe materials, joint methods, fixture types, and performance thresholds. The Department of Safety and Professional Services (DSPS) administers and enforces these standards statewide.

Approved materials must generally meet standards published by one or more recognized standards development organizations, including:

The scope of this page covers material and fixture requirements enforced by DSPS under state plumbing code. It does not cover Wisconsin's private onsite wastewater treatment system (POWTS) standards (addressed separately under Wisconsin Private Onsite Wastewater Systems), nor does it address well and pump system components, which fall under Wisconsin Well and Pump Plumbing Regulations. Federal Safe Drinking Water Act requirements from the U.S. Environmental Protection Agency set a floor that Wisconsin code meets or exceeds, but federal code is not administered through DSPS.

For the full regulatory context governing these material requirements, the Regulatory Context for Wisconsin Plumbing reference describes the broader statutory framework.

How it works

Wisconsin plumbing code does not maintain a single exhaustive approved-products list. Instead, SPS 382 and SPS 384 specify material standards by reference — a product is approved if it meets the cited ASTM, ANSI/NSF, ASME, or AWWA standard for its application category. A licensed plumber or contractor must verify that each material bears third-party certification documentation matching the applicable standard before installation.

Pipe material classification by application:

  1. Potable water supply (interior) — Acceptable materials include Type K, L, and M copper (ASTM B88), CPVC (ASTM D2846 or ASTM F441), PEX (ASTM F876/F877), and PEX-Al-PEX (ASTM F1281). Galvanized steel and unlined iron pipe are not approved for new potable supply installations.
  2. Drain, waste, and vent (DWV) — Acceptable materials include PVC-DWV (ASTM D2665), ABS-DWV (ASTM D2661), cast iron (ASTM A74 or A888), and copper DWV (ASTM B306). The Wisconsin Plumbing Drain Waste Vent Requirements page covers system design standards specific to DWV configuration.
  3. Building sewer (exterior) — PVC sewer pipe (ASTM D3034), ductile iron (AWWA C151), and concrete pipe (ASTM C14) are among the approved options. Flexible fittings must comply with ASTM C1173.
  4. Gas piping — Regulated under SPS 340 (not SPS 382/384) and subject to separate approval criteria; natural gas and LP piping are outside the scope of this page.

Fixture approval criteria:

Plumbing fixtures must bear certification to ASME A112 or ANSI/NSF standards appropriate to their type. Faucets, valves, and fittings used in potable water applications must comply with NSF/ANSI 61 for material safety and NSF/ANSI 372 for lead-free content — a federal requirement reinforced by Wisconsin code following the Reduction of Lead in Drinking Water Act. The Lead-Free Plumbing Compliance Wisconsin reference details the specific lead content thresholds (0.25% weighted average) that fixtures must meet under current federal and state standards.

Common scenarios

New residential construction: SPS 382 governs material selection throughout. PEX supply piping is widely used due to flexibility and freeze resistance. All fixtures must be NSF/ANSI 61 and NSF/ANSI 372 certified. Permits and inspections are managed through local municipalities under DSPS authority. More detail appears at Wisconsin Plumbing for New Construction.

Remodel and renovation projects: Replacement materials must meet current code regardless of what was originally installed. A remodel that opens walls to existing cast iron DWV may retain compliant cast iron but cannot splice in non-listed plastic fittings. Wisconsin Plumbing Remodel and Renovation covers scope triggers for permit requirements.

Backflow prevention devices: Backflow preventers are classified by ASSE International standards (ASSE 1013, ASSE 1015, etc.) and must match the hazard level of the cross-connection they protect. The Backflow Prevention Requirements Wisconsin and Cross-Connection Control Wisconsin pages address device selection and testing requirements.

Water heater replacement: Storage and tankless water heaters must comply with ANSI Z21.10 (gas) or UL 174 (electric) and bear ASME pressure vessel markings where required. Water Heater Regulations Wisconsin covers installation specifics.

Decision boundaries

The primary decision point in material selection is the application category: potable supply, DWV, or building sewer. Within each category, the material's listed standard determines approval status. A material not cited in SPS 382 or SPS 384 for a given application is not approved by default, even if it meets a comparable standard from another jurisdiction.

Type L vs. Type M copper is a frequent comparison point. Type L has a thicker wall and is required by some commercial specifications under SPS 384; Type M is acceptable for most residential supply applications under SPS 382. Both must comply with ASTM B88.

PEX vs. CPVC for hot supply: Both are approved for hot and cold water distribution. PEX requires expansion or crimp fittings per the pipe manufacturer's listed system; mixing PEX pipe from one manufacturer with fittings from a non-listed system voids the listing. CPVC requires solvent cement joints per ASTM F493. Neither may be used above the fixture stop valve in some exposed configurations without code-specific approval.

Inspections at rough-in and final stages confirm material compliance before systems are concealed or placed into service. The Wisconsin Plumbing Permit Application Process outlines the inspection sequence. Material substitutions after permit issuance require inspector approval before installation proceeds.

The Wisconsin Plumbing Materials Standards reference page provides a consolidated index of the ASTM, NSF, ASME, and AWWA designations most frequently cited under Wisconsin code. For an overview of the full plumbing regulatory landscape in the state, the Wisconsin Plumbing Code Overview and the Wisconsin DSPS Plumbing Division pages describe the administrative structure under which these standards are enforced. The main Wisconsin Plumbing Authority index serves as the entry point to all related reference material.

References

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