# Prefabricated Wood I-joist: Building Code Definition

> How the IBC 2009 define prefabricated wood i-joist, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/prefabricated-wood-i-joist/
- 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 (2009 editions transcribed in this corpus) |
| Primary source | IBC 2009 Wood (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 3 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Prefabricated wood i-joist is a defined term in the International Building Code (IBC) 2009, in Wood. The code's own words are: “Structural member manufactured using sawn or structural composite lumber flanges and wood structural panel webs bonded together with exterior exposure adhesives, which forms an "I" cross-sectional shape.” No other I-Code in this corpus defines it, so the IBC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Wood (IBC 2009), Floors (IRC 2009), Definitions (IBC 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?

**Prefabricated Wood I-joist** — IBC 2009, Wood:

> Structural member manufactured using sawn or structural composite lumber flanges and wood structural panel webs bonded together with exterior exposure adhesives, which forms an "I" cross-sectional shape.

![Labeled code-term definition diagram: Prefabricated Wood I-joist: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/prefabricated-wood-i-joist/diagram-1344.webp)

*How the IBC 2009 define prefabricated wood i-joist, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

**Prefabricated Wood I-joist** is defined once in this corpus, in the [Wood](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/wood.md) chapter of the International Building Code (IBC) 2009:

> Structural member manufactured using sawn or structural composite lumber flanges and wood structural panel webs bonded together with exterior exposure adhesives, which forms an "I" cross-sectional shape.

## Where prefabricated wood i-joist is used in the code

The term appears in 3 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Wood](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/wood.md) | IBC 2009 | 9 |
| [Floors](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/floors.md) | IRC 2009 | 4 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/definitions.md) | IBC 2009 | 1 |

## The terms prefabricated wood i-joist is built out of

The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what prefabricated wood i-joist covers:

- **[Structural Composite Lumber](https://harth.build/resources/glossary/structural-composite-lumber.md)** — IBC 2009: Structural member manufactured using wood elements bonded together with exterior adhesives.
- **[Wood Structural Panel](https://harth.build/resources/glossary/wood-structural-panel.md)** — IBC 2009: A panel manufactured from veneers, wood strands or wafers or a combination of veneer and wood strands or wafers bonded together with waterproof synthetic resins or other suitable bonding systems.

## Prefabricated Wood I-joist: 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 | Wood | |
| Re-check the requirement that uses it | Wood (IBC 2009) | |
| Re-check the requirement that uses it | Floors (IRC 2009) | |
| Re-check the requirement that uses it | Definitions (IBC 2009) | |
| Confirm the dependent definition | Structural Composite Lumber | |
| Confirm the dependent definition | Wood Structural Panel | |
| 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)
- [Structural Composite Lumber: Building Code Definition](https://harth.build/resources/glossary/structural-composite-lumber.md)
- [Wood Structural Panel: Building Code Definition](https://harth.build/resources/glossary/wood-structural-panel.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 prefabricated wood i-joist?

The International Building Code (IBC) 2009 defines it in Wood as: “Structural member manufactured using sawn or structural composite lumber flanges and wood structural panel webs bonded together with exterior exposure adhesives, which forms an "I" cross-sectional shape.” 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 prefabricated wood i-joist?

In this corpus the term is used across 3 chapters, led by Wood 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.

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