# Concealed Piping: Building Code Definition

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

- Canonical: https://harth.build/resources/glossary/concealed-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 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Fuel Gas (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 4 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Concealed piping is a defined term in the International Residential Code (IRC) 2009, in Fuel Gas. The code's own words are: “Piping that is located in a concealed location (see “Concealed location”).” No other I-Code in this corpus defines it, so the IRC 2009 definition is the one to work from. The term is used in 4 chapters of this corpus, most often in Fixtures, Faucets and Fixture Fittings (IPC 2009), Sanitary Drainage (IPC 2009), Fuel Gas (IRC 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?

**Concealed Piping** — IRC 2009, Fuel Gas:

> Piping that is located in a concealed location (see “Concealed location”).

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

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

## What must be verified before using this guidance?

**Concealed Piping** is defined once in this corpus, in the [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) chapter of the International Residential Code (IRC) 2009:

> Piping that is located in a concealed location (see “Concealed location”).

## Where concealed piping is used in the code

The term appears in 4 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Fixtures, Faucets and Fixture Fittings](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/fixtures-faucets-and-fixture-fittings.md) | IPC 2009 | 2 |
| [Sanitary Drainage](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/sanitary-drainage.md) | IPC 2009 | 2 |
| [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 2 |
| [Sanitary Drainage](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/sanitary-drainage.md) | IRC 2009 | 2 |

### The term in use

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

> Access shall be provided to concealed piping in connection with special fixtures where such piping contains steam traps, valves, relief valves, check valves, vacuum breakers or other similar items that require periodic inspection, servicing, maintenance or repair.

— [IPC 2009 §422.5](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/fixtures-faucets-and-fixture-fittings.md)

> Cleanouts on concealed piping or piping under a floor slab or in a crawl space of less than 24 inches (610 mm) in height or a plenum shall be extended through and terminate flush with the finished wall, floor or ground surface or shall be extended to the outside of the building.

— [IPC 2009 §708.4](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/sanitary-drainage.md)

> Concealed piping shall not be located in solid partitions and solid walls, unless installed in a chase or casing.

— [IRC 2009 §G2415.2](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md)

> A fixture trap or a fixture with integral trap, readily removable without disturbing concealed piping shall be acceptable as a cleanout equivalent.

— [IRC 2009 §P3005.2.10](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/sanitary-drainage.md)


## The terms concealed piping is built out of

The definition above leans on 3 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what concealed piping covers:

- **[Concealed Location](https://harth.build/resources/glossary/concealed-location.md)** — IRC 2009: A location that cannot be accessed without damaging permanent parts ofthe building structure or finish surface.
- **[Concealed](https://harth.build/resources/glossary/concealed.md)** — IRC 2009: Rendered inaccessible by the structure or finish of the building.
- **[Piping](https://harth.build/resources/glossary/piping.md)** — IRC 2009: Where used in this code, “piping” refers to either pipe or tubing, or both.

## Concealed 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 | |
| Re-check the requirement that uses it | Fixtures, Faucets and Fixture Fittings (IPC 2009) | |
| Re-check the requirement that uses it | Sanitary Drainage (IPC 2009) | |
| Re-check the requirement that uses it | Fuel Gas (IRC 2009) | |
| Re-check the requirement that uses it | Sanitary Drainage (IRC 2009) | |
| Confirm the dependent definition | Concealed Location | |
| Confirm the dependent definition | Concealed | |
| Confirm the dependent definition | Piping | |
| 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)
- [Concealed Location: Building Code Definition](https://harth.build/resources/glossary/concealed-location.md)
- [Concealed: Building Code Definition](https://harth.build/resources/glossary/concealed.md)
- [Piping: Building Code Definition](https://harth.build/resources/glossary/piping.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 concealed piping?

The International Residential Code (IRC) 2009 defines it in Fuel Gas as: “Piping that is located in a concealed location (see “Concealed location”).” 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 concealed piping?

In this corpus the term is used across 4 chapters, led by Fixtures, Faucets and Fixture Fittings in the IPC 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.

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