# Draftstop: Building Code Definition

> How the IBC 2009, IFC 2009 define draftstop, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/draftstop/
- 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 | IBC 2009, IFC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IBC 2009 Fire and Smoke Protection Features (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 11 (counted across the codes hosted here) |
| Wording identical across codes | Yes (compare before citing one code's wording under another) |

## Direct answer

Draftstop is a defined term in the International Building Code (IBC) 2009, in Fire and Smoke Protection Features. The code's own words are: “A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics.” The IFC 2009 carries the same definition word for word, so the term means the same thing in each. The term is used in 11 chapters of this corpus, most often in Fire and Smoke Protection Features (IBC 2009), Building Planning (IRC 2009), Fire-resistance-rated Construction (IFC 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?

**Draftstop** — IBC 2009, Fire and Smoke Protection Features:

> A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics.

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

*How the IBC 2009, IFC 2009 define draftstop, 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 **Draftstop**, in identical words.

| Code | Where it is defined | Definition |
| --- | --- | --- |
| IBC 2009 | [Fire and Smoke Protection Features](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-and-smoke-protection-features.md) | A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics. |
| IFC 2009 | [Fire-resistance-rated Construction](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/fire-resistance-rated-construction.md) | A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics. |

## Where draftstop is used in the code

The term appears in 11 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Fire and Smoke Protection Features](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-and-smoke-protection-features.md) | IBC 2009 | 63 |
| [Building Planning](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/building-planning.md) | IRC 2009 | 8 |
| [Fire-resistance-rated Construction](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/fire-resistance-rated-construction.md) | IFC 2009 | 5 |
| [Floors](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/floors.md) | IRC 2009 | 2 |
| [General Requirements](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/general-requirements.md) | IRC 2009 | 2 |
| [Scope and Administration](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/scope-and-administration.md) | IRC 2009 | 2 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/definitions.md) | IBC 2009 | 1 |
| [Definitions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/definitions.md) | IFC 2009 | 1 |
| [Exhaust Systems](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/exhaust-systems.md) | IMC 2009 | 1 |
| [Scope and Administration](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/scope-and-administration.md) | IPC 2009 | 1 |
| [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 1 |

## The terms draftstop 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 draftstop covers:

- **[Concealed](https://harth.build/resources/glossary/concealed.md)** — IRC 2009: Rendered inaccessible by the structure or finish of the building.
- **[Building](https://harth.build/resources/glossary/building.md)** — IBC 2009: Any structure used or intended for supporting or sheltering any use or occupancy.
- **[Device](https://harth.build/resources/glossary/device.md)** — IRC 2009: Aunit of an electrical system that carries or controls electrical energy as it principal function.

## Draftstop: 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 IBC | Fire and Smoke Protection Features | |
| Read the definition in the adopted IFC | Fire-resistance-rated Construction | |
| Re-check the requirement that uses it | Fire and Smoke Protection Features (IBC 2009) | |
| Re-check the requirement that uses it | Building Planning (IRC 2009) | |
| Re-check the requirement that uses it | Fire-resistance-rated Construction (IFC 2009) | |
| Re-check the requirement that uses it | Floors (IRC 2009) | |
| Confirm the dependent definition | Concealed | |
| Confirm the dependent definition | Building | |
| Confirm the dependent definition | Device | |
| 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: Building Code Definition](https://harth.build/resources/glossary/concealed.md)
- [Building: Building Code Definition](https://harth.build/resources/glossary/building.md)
- [Device: Building Code Definition](https://harth.build/resources/glossary/device.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 draftstop?

The International Building Code (IBC) 2009 defines it in Fire and Smoke Protection Features as: “A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics.” 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 draftstop?

In this corpus the term is used across 11 chapters, led by Fire and Smoke Protection Features in the IBC 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 a draftstop?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IBC 2009 states, in Fire and Smoke Protection Features: “A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics.” It is defined in IBC 2009, IFC 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.

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