Ohio’s plumbing rules were updated with an effective date of October 15, 2025. The Ohio Plumbing Code, Ohio Administrative Code 4101:3, now incorporates chapters 2 through 15 of the 2021 International Plumbing Code, with Ohio’s own amendments layered on top. For most homeowners the news is quiet, but it sets the rules every repipe permit is inspected against. Slate Repiping Columbus offers and manages permitted repipes across Columbus and nearby Franklin County communities, carried out by licensed and insured plumbing contractors, so here is what the update covers and what it means in practice.
Who the code covers
The Ohio Plumbing Code is not only for commercial buildings; the Residential Code of Ohio points to it. Section 2501.1 of the residential code makes the Ohio Plumbing Code govern plumbing in 1, 2 and 3 family homes, and the residential code’s own water supply sections are deleted in favor of the plumbing code. So a repipe in a Columbus single-family house, a double or a triplex is built to the same plumbing code as a larger building, with the residential details the code provides.
Enforcement runs through certified building departments or the state’s Division of Industrial Compliance. Inside the City of Columbus that is Building and Zoning Services. In many suburbs, Franklin County Public Health reviews and inspects plumbing under contract while the city issues the permit. The Columbus repiping permit guide maps which office covers which address.
What Ohio amended in the water supply chapter
Chapter 6 of the International Plumbing Code covers water supply and distribution, the part a repipe lives in. Ohio’s amendments to that chapter touch several sections:
- 603.2: separation of the water service from the building sewer.
- 605.2.1: exceptions in the lead content requirements.
- 605.3: the language on listed materials.
- 606.1 and 606.2: where shutoff valves go. Ohio’s text calls for separate shutoffs for each unit in multi-unit buildings other than 1, 2 and 3 family homes, and fixture shutoffs in 1, 2 and 3 family homes, except at tubs and showers.
- 607.5: pipe insulation.
No Ohio amendment was found to section 604.8, the model code’s pressure-reducing valve requirement, so the general rule stands: where static pressure inside a building exceeds 80 psi, a pressure-reducing valve belongs on the supply. The guide to Columbus water pressure and hard water explains how to check your own pressure.
The amended text is long and specific. This post names the sections; the inspector and the code text decide how they apply to a given house.
Planning a repipe under the current code?
A walk-through sets the material, the shutoffs and the permit in a written scope before work starts.
What it means for a repipe
Materials. The 2021 International Plumbing Code lists PEX, CPVC and copper tube for water distribution. In Columbus, the choice between them is about the house, not the law. The PEX vs copper guide compares them, and PEX repiping and copper repiping explain each.
Lead-free parts. Pipe, fittings and valves for drinking water have to meet lead-free requirements. That matters most in older Columbus houses, where, according to the City, brass fittings could contain up to 8% lead until 2014 and copper joints made before 1986 may hold lead solder. A repipe replaces those parts in the runs it covers.
Shutoffs. With fixture shutoffs called for in 1, 2 and 3 family homes, a repipe includes stops at sinks and toilets, and the scope should say how tubs and showers are handled. In a building with four or more units, each unit’s shutoff becomes part of the design; see commercial and multi-unit repiping. A manifold layout puts many of these valves in one place.
Insulation and testing. Ohio’s amendment to the pipe insulation section is one more reason to ask how exposed runs will be insulated. Every repipe is also pressure tested before walls close and inspected while the pipe is visible.
What does not change
A code update does not, by itself, require anyone to replace plumbing that was lawfully installed under an earlier code. It applies to new work. A house with old galvanized pipe that still works is not out of compliance because the code moved on; it becomes a question when the pipe is replaced, extended or altered.
The permit process also stays the same. Inside Columbus, the plumbing permit for a 1, 2 or 3 family home costs $275 with two inspections. A separate change came from Franklin County Public Health: since February 9, 2026, plumbing permit applications in the cities it serves have to include its plan review approval with a matching fixture count. That is a county procedure, not part of the state code update.
For a full picture of the work the code governs, start with the repiping guide, or call Slate Repiping Columbus with a question about your house.