# Fixture Drain: Building Code Definition

> How the IRC 2009, IPC 2009 define fixture drain, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/fixture-drain/
- 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, IPC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 7 (counted across the codes hosted here) |
| Wording identical across codes | No (compare before citing one code's wording under another) |

## Direct answer

Fixture drain is a defined term in the International Residential Code (IRC) 2009, in Definitions. The code's own words are: “The drain from the trap of a fixture to the junction of that drain with any other drain pipe.” The IPC 2009 defines the same term with different wording, so the controlling text depends on which code governs the question in front of you — the comparison below sets the versions side by side. The term is used in 7 chapters of this corpus, most often in Vents (IPC 2009), Vents (IRC 2009), Fixtures, Faucets and Fixture Fittings (IPC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted.

*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?

**Fixture Drain** — IRC 2009, Definitions:

> The drain from the trap of a fixture to the junction of that drain with any other drain pipe.

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

*How the IRC 2009, IPC 2009 define fixture drain, 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 **Fixture Drain**, and the wording is not identical — read the version that governs your question.

| Code | Where it is defined | Definition |
| --- | --- | --- |
| IRC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | The drain from the trap of a fixture to the junction of that drain with any other drain pipe. |
| IPC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/definitions.md) | The drain from the trap of a fixture to a junction with any other drain pipe. |

## Where fixture drain is used in the code

The term appears in 7 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Vents](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/vents.md) | IPC 2009 | 49 |
| [Vents](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/vents.md) | IRC 2009 | 41 |
| [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 | 4 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | IRC 2009 | 4 |
| [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/definitions.md) | IPC 2009 | 3 |
| [Sanitary Drainage](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/sanitary-drainage.md) | IPC 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 fixture drain, quoted from the 2009 text hosted here:

> Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 906.1.

— [IPC 2009 §906.1](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/vents.md)

> Each fixture trap shall have a protecting vent located so that the slope and the developedlengthin the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table P31 05.1.

— [IRC 2009 §P3105.1](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/vents.md)

> The trap and fixture drain for an automatic clothes washer standpipe shall be a minimum of 2 inches (51 mm) in diameter.

— [IPC 2009 §406.3](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/fixtures-faucets-and-fixture-fittings.md)


## The terms fixture drain is built out of

The definition above leans on 1 other defined term. Each carries its own code definition, and a local amendment to any of them changes what fixture drain covers:

- **[Drain](https://harth.build/resources/glossary/drain.md)** — IRC 2009: Any pipe that carries soil and water-borne wastes in a building drainage system.

## Fixture Drain: 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 | Definitions | |
| Read the definition in the adopted IPC | Definitions | |
| Re-check the requirement that uses it | Vents (IPC 2009) | |
| Re-check the requirement that uses it | Vents (IRC 2009) | |
| Re-check the requirement that uses it | Fixtures, Faucets and Fixture Fittings (IPC 2009) | |
| Re-check the requirement that uses it | Definitions (IRC 2009) | |
| Confirm the dependent definition | Drain | |
| 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)
- [Drain: Building Code Definition](https://harth.build/resources/glossary/drain.md)
- [Building: Building Code Definition](https://harth.build/resources/glossary/building.md)
- [Construction Documents: Building Code Definition](https://harth.build/resources/glossary/construction-documents.md)
- [Registered Design Professional: Building Code Definition](https://harth.build/resources/glossary/registered-design-professional.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 fixture drain?

The International Residential Code (IRC) 2009 defines it in Definitions as: “The drain from the trap of a fixture to the junction of that drain with any other drain pipe.” 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 fixture drain?

In this corpus the term is used across 7 chapters, led by Vents 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.

### Is a floor drain considered a fixture?

Floor Drain is a separate defined term. The IRC 2009 defines it as: “A plumbing fixture for recess in the floor having a floor-level strainer intended for the purpose of the collection and disposal of waste water used in cleaning the floor and for the collection and disposal of accidental spillage to the floor.” That is not the same as fixture drain, which the IRC 2009 defines as “The drain from the trap of a fixture to the junction of that drain with any other drain pipe.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

### What are considered fixtures 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 fixture drain, which the IRC 2009 defines as “The drain from the trap of a fixture to the junction of that drain with any other drain pipe.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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