Approved Plumbing Materials and Products in North Dakota
North Dakota's plumbing sector operates under a defined materials approval framework that determines which pipes, fittings, fixtures, and joining compounds may be lawfully installed in licensed plumbing systems. Material selection is not discretionary — it is governed by adopted code editions, state-level administrative rules, and product certification standards enforced at the permit and inspection stage. This page describes the classification structure for approved plumbing materials and products, how approval status is established and verified, and where classification decisions become consequential for installers, inspectors, and building owners.
Definition and scope
Approved plumbing materials in North Dakota are products that satisfy the material and performance requirements of the adopted state plumbing code — the 2018 Uniform Plumbing Code (UPC), as administered by the North Dakota State Plumbing Board (NDSPB). Approval is not a state-issued product certificate; rather, it reflects conformance with nationally recognized standards bodies including NSF International, ASTM International, ANSI (American National Standards Institute), and IAPMO (International Association of Plumbing and Mechanical Officials), which publishes the UPC.
Scope of this materials framework covers:
- Potable water supply piping and fittings (interior and exterior)
- Drain, waste, and vent (DWV) system components
- Fixture materials (sinks, toilets, tubs, shower bases)
- Joining materials (solvents, solders, thread compounds)
- Valves, backflow preventers, and pressure regulators
- Water heater tanks and associated connection materials
Products installed outside this scope — such as industrial process piping not connected to a potable or sanitary system — may fall under separate regulatory frameworks administered by agencies other than the NDSPB. Gas piping material requirements, while governed by the same licensing structure, derive from the National Fuel Gas Code (NFPA 54) and are addressed separately under North Dakota Plumbing Code Standards.
How it works
Product approval flows through a tiered verification chain rather than a single state registry:
- Standards body listing: A product must carry a listing mark from a recognized certification organization — most commonly NSF, IAPMO's listing service, or UL — confirming it meets the relevant ASTM or ANSI standard (e.g., ASTM D2665 for PVC DWV pipe, ASTM B88 for copper water tube).
- Code table compliance: The 2018 UPC contains material-specific tables for water supply piping (Table 604.1), building sewer pipe (Table 702.1), and DWV systems (Table 701.1). A product must appear in the applicable table category to be specified without a variance request.
- Inspector verification at rough-in: During rough-in inspection, the licensed plumbing inspector confirms that installed materials bear appropriate listing marks and that pipe markings (type designation, pressure rating, standard number) are legible and match the permitted specification.
- Alternate approval pathway: Materials not enumerated in UPC tables may be submitted to the NDSPB for evaluation under the alternate materials and methods provision. Approval requires documented performance data demonstrating equivalence to code-listed materials.
For water-contact materials specifically, NSF/ANSI 61 (drinking water system components) and NSF/ANSI 372 (lead-free compliance) certifications are baseline requirements — a point addressed in detail under Lead-Free Plumbing Compliance in North Dakota. The full regulatory context for how North Dakota administers these requirements is described at Regulatory Context for North Dakota Plumbing.
Common scenarios
Potable water supply piping: Copper (Types K, L, and M per ASTM B88), cross-linked polyethylene (PEX, ASTM F876/F877), and CPVC (ASTM D2846) are the most common approved materials for interior supply lines in North Dakota residential construction. PEX has displaced rigid copper in substantial volume for new residential work, partly due to freeze-resistance characteristics relevant to Winterization and Freeze Protection Plumbing in North Dakota. Galvanized steel supply pipe is code-permitted in certain applications but is rarely specified in new installations.
DWV systems: ABS (ASTM D2661) and PVC (ASTM D2665) plastic pipe dominate drain, waste, and vent installations. Cast iron (ASTM A74, hubless per CISPI 301) remains the standard for high-noise-sensitivity applications such as multi-family or commercial structures. The structural requirements for DWV systems in North Dakota are covered under Drain, Waste, and Vent Systems in North Dakota.
Fixture certification: Plumbing fixtures — including water closets, lavatories, and showerheads — must meet ASME A112 standards. Water closets installed after the federal 1.6-gallon-per-flush conservation threshold (established under the Energy Policy Act of 1992) must comply with that federal maximum regardless of code edition.
Backflow prevention devices: Devices must be listed by the Foundation for Cross-Connection Control and Hydraulic Research (USC-FCCCHR) or an equivalent recognized testing laboratory. Relevant classification and installation requirements are detailed under Backflow Prevention Requirements in North Dakota.
Decision boundaries
The critical classification distinction in North Dakota materials practice is between listed materials and alternate materials:
| Attribute | Listed Material | Alternate Material |
|---|---|---|
| Code table reference | Present (UPC Table 604.1, 701.1, 702.1) | Absent |
| Certification mark required | Yes (NSF, IAPMO, UL, or equivalent) | Yes, plus equivalency data |
| Inspector authority | Approve on-sight if mark present | Must have prior NDSPB approval |
| Permit risk | Low | Elevated; potential stop-work |
A second boundary involves joining method compatibility: the code specifies approved joining methods for each pipe material. PEX may use crimp (ASTM F1807), clamp (ASTM F2098), or press-fit connections — but solvent-weld joints applicable to PVC are not transferable. Mixing material types at connections requires transition fittings listed for that specific transition.
The North Dakota Plumbing Authority home reference indexes the full scope of North Dakota plumbing sector topics, including licensing, contractor requirements, and code adoption history relevant to material standards. Inspectors and licensed contractors are the authorized parties for field determinations about material acceptability — the NDSPB does not issue pre-installation product approvals for individual projects outside the formal alternate materials process.
Scope limitations: This page addresses materials regulated under the North Dakota State Plumbing Board's jurisdiction for plumbing systems as defined by the UPC. It does not cover mechanical system materials, fire suppression piping (governed by NFPA 13 2022 edition and separate authority), or public water main materials regulated by the North Dakota Department of Environmental Quality (NDDEQ). Rural and private water system material considerations are addressed under Well Water and Private Water System Plumbing in North Dakota.
References
- North Dakota State Plumbing Board (NDSPB)
- IAPMO — 2018 Uniform Plumbing Code
- NSF International — NSF/ANSI 61 Drinking Water System Components
- NSF International — NSF/ANSI 372 Lead-Free Compliance
- ASTM International — Plumbing and Piping Standards
- North Dakota Department of Environmental Quality (NDDEQ)
- USC Foundation for Cross-Connection Control and Hydraulic Research
- ASME A112 Plumbing Standards
- Energy Policy Act of 1992 — Water Conservation Provisions