# Fiber-cement Siding: Building Code Definition

> How the IBC 2009, IRC 2009 define fiber-cement siding, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/fiber-cement-siding/
- 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, IRC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IBC 2009 Exterior Walls (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 2 (counted across the codes hosted here) |
| Wording identical across codes | No (compare before citing one code's wording under another) |

## Direct answer

Fiber-cement siding is a defined term in the International Building Code (IBC) 2009, in Exterior Walls. The code's own words are: “A manufactured, fiber-reinforcing product made with an inorganic hydraulic or calcium silicate binder formed by chemical reaction and reinforced with discrete organic or inorganic nonasbestos fibers, or both. Additives that enhance manufacturing or product performance are permitted. Fiber-cement siding products have either smooth or textured faces and are intended for exterior wall and related applications.” The IRC 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 2 chapters of this corpus, most often in Exterior Walls (IBC 2009), Definitions (IRC 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?

**Fiber-cement Siding** — IBC 2009, Exterior Walls:

> A manufactured, fiber-reinforcing product made with an inorganic hydraulic or calcium silicate binder formed by chemical reaction and reinforced with discrete organic or inorganic nonasbestos fibers, or both. Additives that enhance manufacturing or product performance are permitted. Fiber-cement siding products have either smooth or textured faces and are intended for exterior wall and related applications.

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

*How the IBC 2009, IRC 2009 define fiber-cement siding, 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 **Fiber-cement Siding**, and the wording is not identical — read the version that governs your question.

| Code | Where it is defined | Definition |
| --- | --- | --- |
| IBC 2009 | [Exterior Walls](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/exterior-walls.md) | A manufactured, fiber-reinforcing product made with an inorganic hydraulic or calcium silicate binder formed by chemical reaction and reinforced with discrete organic or inorganic nonasbestos fibers, or both. Additives that enhance manufacturing or product performance are permitted. Fiber-cement siding products have either smooth or textured faces and are intended for exterior wall and related applications. |
| IRC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | A manufactured, fiber-reinforcing product made with an inorganic hydraulic or calcium silicate binder formed by chemical reaction and reinforced with discrete organic or inorganic nonasbestos fibers, or both. Additives which enhance manufacturing or product performance are permitted. Fiber-cement siding products have either smooth or textured faces and are intended for exterior wall and related applications. |

## Where fiber-cement siding is used in the code

The term appears in 2 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Exterior Walls](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/exterior-walls.md) | IBC 2009 | 6 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | IRC 2009 | 2 |

### The term in use

How the code actually writes about fiber-cement siding, quoted from the 2009 text hosted here:

> Fiber-cement siding shall conform to the requirements of ASTM C 1186, Type A, and shall be so identified on labeling listing an approved quality control agency.

— [IBC 2009 §1404.10](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/exterior-walls.md)


## The terms fiber-cement siding 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 fiber-cement siding covers:

- **[Exterior Wall](https://harth.build/resources/glossary/exterior-wall.md)** — IBC 2009: A wall, bearing or nonbearing, that is used as an enclosing wall for a building, other than a fire wall, and that has a slope of 60 degrees (1.05 rad) or greater with the horizontal plane.
- **[Chemical](https://harth.build/resources/glossary/chemical.md)** — IFC 2009: An element, chemical compound or mixture of elements or compounds or both.

## Fiber-cement Siding: 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 | Exterior Walls | |
| Read the definition in the adopted IRC | Definitions | |
| Re-check the requirement that uses it | Exterior Walls (IBC 2009) | |
| Re-check the requirement that uses it | Definitions (IRC 2009) | |
| Confirm the dependent definition | Exterior Wall | |
| Confirm the dependent definition | Chemical | |
| 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)
- [Exterior Wall: Building Code Definition](https://harth.build/resources/glossary/exterior-wall.md)
- [Chemical: Building Code Definition](https://harth.build/resources/glossary/chemical.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 fiber-cement siding?

The International Building Code (IBC) 2009 defines it in Exterior Walls as: “A manufactured, fiber-reinforcing product made with an inorganic hydraulic or calcium silicate binder formed by chemical reaction and reinforced with discrete organic or inorganic nonasbestos fibers, or both. Additives that enhance manufacturing or product performance are permitted. Fiber-cement siding products have either smooth or textured faces and are intended for exterior wall and related applications.” 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 fiber-cement siding?

In this corpus the term is used across 2 chapters, led by Exterior Walls 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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