# Piping: Building Code Definition

> How the IRC 2009, IMC 2009 define piping, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/piping/
- Last updated: 2026-09-07
- Data source: Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IRC 2009, IMC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Fuel Gas (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 92 (counted across the codes hosted here) |
| Wording identical across codes | Yes (compare before citing one code's wording under another) |

## Direct answer

Piping is a defined term in the International Residential Code (IRC) 2009, in Fuel Gas. The code's own words are: “Where used in this code, “piping” refers to either pipe or tubing, or both.” The IMC 2009 carries the same definition word for word, so the term means the same thing in each. The term is used in 92 chapters of this corpus, most often in Fuel Gas (IRC 2009), Flammable and Combustible Liquids (IFC 2009), Motor Fuel-dispensing Facilities and Repair Garages (IFC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it.

*Content and cited inputs reviewed by [Scott Barrington](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Piping** — IRC 2009, Fuel Gas:

> Where used in this code, “piping” refers to either pipe or tubing, or both.

![Labeled code-term definition diagram: Piping: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/piping/diagram-1344.webp)

*How the IRC 2009, IMC 2009 define piping, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

Two of the I-Codes in this corpus define **Piping**, in identical words.

| Code | Where it is defined | Definition |
| --- | --- | --- |
| IRC 2009 | [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | Where used in this code, “piping” refers to either pipe or tubing, or both. |
| IMC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) | Where used in this code, "piping" refers to either pipe or tubing, or both. |

## Where piping is used in the code

The term appears in 92 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 294 |
| [Flammable and Combustible Liquids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md) | IFC 2009 | 275 |
| [Motor Fuel-dispensing Facilities and Repair Garages](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/motor-fuel-dispensing-facilities-and-repair-garages.md) | IFC 2009 | 132 |
| [Special Detailed Requirements Based on Use and Occupancy](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/special-detailed-requirements-based-on-use-and-occupancy.md) | IBC 2009 | 109 |
| [Water Supply and Distribution](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/water-supply-and-distribution.md) | IRC 2009 | 94 |
| [Cryogenic Fluids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/cryogenic-fluids.md) | IFC 2009 | 66 |
| [Hazardous Materials-general Provisions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md) | IFC 2009 | 61 |
| [Hydronic Piping](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/hydronic-piping.md) | IMC 2009 | 57 |
| [Sanitary Drainage](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/sanitary-drainage.md) | IPC 2009 | 55 |
| [Water Supply and Distribution](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/water-supply-and-distribution.md) | IPC 2009 | 55 |
| [Sanitary Drainage](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/sanitary-drainage.md) | IRC 2009 | 55 |
| [Highly Toxic and Toxic Materials](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/highly-toxic-and-toxic-materials.md) | IFC 2009 | 48 |

_80 further chapters mention the term._

### The term in use

How the code actually writes about piping, quoted from the 2009 text hosted here:

> The building shall not be weakened by the installation of any gas piping.

— [IRC 2009 §G2405.1](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md)

> Piping containing flammable liquids shall be identified in accordance with ASME AI3.1.

— [IFC 2009 §3403.5.2](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md)

> Accurate daily inventory records shall be maintained and reconciled on underground fuel storage tanks for indication of possible leakage from tanks and piping.

— [IFC 2009 §2206.2.1.1](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/motor-fuel-dispensing-facilities-and-repair-garages.md)

## Piping: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IRC | Fuel Gas | |
| Read the definition in the adopted IMC | Definitions | |
| Re-check the requirement that uses it | Fuel Gas (IRC 2009) | |
| Re-check the requirement that uses it | Flammable and Combustible Liquids (IFC 2009) | |
| Re-check the requirement that uses it | Motor Fuel-dispensing Facilities and Repair Garages (IFC 2009) | |
| Re-check the requirement that uses it | Special Detailed Requirements Based on Use and Occupancy (IBC 2009) | |
| Local amendment to any of the above | Jurisdiction's amendment list | |

**A research aid, not a code determination.** The authority having jurisdiction decides which edition and which amendments apply.

## Where can you explore related guidance?

- [Explore all glossary guidance](https://harth.build/resources/glossary.md)
- [Code Official: Building Code Definition](https://harth.build/resources/glossary/code-official.md)
- [Code: Building Code Definition](https://harth.build/resources/glossary/code.md)
- [Fuel Gas: Building Code Definition](https://harth.build/resources/glossary/fuel-gas.md)
- [Vent: Building Code Definition](https://harth.build/resources/glossary/vent.md)

## Sources and method

Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of piping?

The International Residential Code (IRC) 2009 defines it in Fuel Gas as: “Where used in this code, “piping” refers to either pipe or tubing, or both.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.

### Which parts of the code depend on piping?

In this corpus the term is used across 92 chapters, led by Fuel Gas in the IRC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.

### What is the definition of piping?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IRC 2009 states, in Fuel Gas: “Where used in this code, “piping” refers to either pipe or tubing, or both.” It is defined in IRC 2009, IMC 2009. Because it is a defined term, whatever the adopted edition says it means is what every section using it means — so check Chapter 2 of that edition and any local amendment before relying on this wording.

### What is IRC in plumbing?

Plumbing is a separate defined term. The IRC 2009 defines it as: “For the purpose of this code, plumbing refers to those installations, repairs, maintenance and alterations regulated by Chapters 25 through 33.” That is not the same as piping, which the IRC 2009 defines as “Where used in this code, “piping” refers to either pipe or tubing, or both.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

---

- Continue in Harth (open this topic in the Harth agent): https://app.harth.build/agent?context=%2Fresources%2Fglossary%2Fpiping%2F
- View this page in a browser: https://harth.build/resources/glossary/piping/
- All resources for agents: https://harth.build/llms.txt