The Maine Pipe Book Maine plumbing code guide

Legacy rules · the Chapter 13 question

The old rules: Maine’s state-written plumbing code

Before Maine joined the UPC family, plumbing ran on rules the state wrote itself. Ask a veteran plumber about “the old chapter rules” and you’ll hear about them — and about Chapter 13, a number that means three different things in Maine plumbing depending on who’s talking.

Ch. 238 — repealedReplaced by Ch. 4 / UPC

The legacy code

The State of Maine Internal Plumbing Code (Chapter 238)

Maine’s legacy internal plumbing rules were a state-written code, not an adopted national model. For much of their life they were administered on the health side of state government — the Division of Health Engineering within what became DHHS — reflecting plumbing’s roots as a sanitation program. The rules were eventually carried in the Plumbers’ Examining Board’s rule set as Chapter 238, the State of Maine Internal Plumbing Code.

The Secretary of State’s rule index still lists Chapter 238 with the annotation “replaced by Ch. 4” — the formal record of the handoff from Maine’s homegrown rules to the adopted Uniform Plumbing Code that now lives in Chapter 4, Installation Standards.

Character of the old rules, as working plumbers remember them:

Why the old rules still matter Any system lawfully installed under the legacy code is generally allowed to remain in service — maintained and repaired to its original design — so long as it isn’t a hazard. Most of the plumbing in Maine’s older housing stock was installed under these rules, so evaluating an existing building means reading it against the code of its day, not today’s UPC. See when updates are required.

The Chapter 13 question

Three things “Chapter 13” can mean in Maine plumbing

“Chapter 13” comes up constantly in Maine plumbing conversations, and it rarely means the same thing twice. Here are the three legitimate referents — sort out which one your counterpart means before you argue about it:

Disambiguating “Chapter 13”
ReferentWhat it isStatus in Maine
UPC Chapter 13
Health Care Facilities
The model code’s chapter on plumbing in hospitals, clinics, and similar occupancies (special waste, medical gas interfaces, fixture requirements). Not adopted. Maine’s Chapter 4 excludes it, along with the fuel-gas chapter and the appendices. Health-facility plumbing in Maine is governed by the adopted chapters plus facility licensing requirements — not by UPC Ch. 13.
Maine Fuel Board Chapter 13
02-658 CMR Ch. 13
“Installation of Propane and Natural Gas Burning Equipment” — the gas-side rule that governs appliance installs, and whose installation section (§ 658-13-4) hands water-side work back to the plumbing rules: piping and safety controls on water heaters, domestic water connections to boilers, and condensate disposal must follow Plumbers’ Examining Board rules, with condensate neutralized and drained through an air gap to sanitary drainage. Active. This is the “Chapter 13” that gas technicians and plumbers actually share jobs under today — the boundary line between the two trades on every boiler and on-demand water heater install in the state.
The old state rules, colloquially Veterans sometimes use old chapter numbers as shorthand for the pre-UPC state-written rules generally — the era when Maine’s internal plumbing code was its own document with its own chapter scheme, formally recorded as rule Chapter 238 before repeal. Repealed and replaced. Historic reference only; governs nothing new, but explains what you find opened up inside older Maine walls.
Practical rule of thumb If the conversation is about a boiler, water heater, or condensate line on a gas job, assume Fuel Board Chapter 13. If it’s about a hospital or clinic, someone is citing the unadopted UPC chapter. If it’s an old-timer describing how things used to be done, they mean the legacy state code.

Then vs. now

What changed when the UPC arrived

Legacy state rules vs. adopted 2021 UPC — selected contrasts
TopicLegacy state-written rulesCurrent Maine 2021 UPC
Source documentMaine-drafted text (NSPC-influenced), rule Ch. 238 National model code (IAPMO UPC) adopted by reference in rule Ch. 4, with Maine amendments
UpdatesAmended ad hoc by state rulemaking Tracks the UPC’s 3-year model cycle; Maine adopts editions on its own schedule
Materials & methodsNarrower approved-materials lists Broad referenced-standards tables (PEX, PP, PVC/ABS DWV, press fittings, etc.)
VentingConventional venting, Maine-specific quirks Full UPC venting chapter plus Maine’s future-vent and snow-height amendments
InterpretationState officials and local inspectors Board + LPIs, with the national UPC commentary ecosystem behind it

The practical upside of the switch: Maine plumbers, engineers, and suppliers now work from a document the rest of the UPC-family states share, with training material, commentary, and listed products keyed to it. The cost: Maine-specific knowledge moved into the amendment document, where it’s easy to miss if you learned the code somewhere else.

Plain-language guide, not legal advice. This site summarizes Maine plumbing statutes, board rules, and the adopted plumbing code for general information. Code editions, amendments, and fees change; municipalities may apply stricter local requirements. Always confirm current requirements with the Maine Plumbers’ Examining Board, your Local Plumbing Inspector (LPI), and the adopted code text before performing or specifying work.