Building Code Glossary
Backing: Building Code Definition
How the IBC 2009 define backing, where the wording differs, and which chapters depend on the term.
On this page
Last updated September 7, 2026 · 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.
Direct answer
Backing is a defined term in the International Building Code (IBC) 2009, in Exterior Walls. The code's own words are: “The wall or surface to which the veneer is secured.” 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 18 chapters of this corpus, most often in Gypsum Board and Plaster (IBC 2009), Wall Covering (IRC 2009), Exterior Walls (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, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.
What does this term mean?
Backing — IBC 2009, Exterior Walls:
The wall or surface to which the veneer is secured.
What must be verified before using this guidance?
Backing is defined once in this corpus, in the Exterior Walls chapter of the International Building Code (IBC) 2009:
The wall or surface to which the veneer is secured.
Where backing is used in the code
The term appears in 18 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Gypsum Board and Plaster | IBC 2009 | 44 |
| Wall Covering | IRC 2009 | 43 |
| Exterior Walls | IBC 2009 | 27 |
| Wall Construction | IRC 2009 | 23 |
| Interior Finishes | IBC 2009 | 8 |
| Glass and Glazing | IBC 2009 | 5 |
| Building Planning | IRC 2009 | 5 |
| Wood | IBC 2009 | 3 |
| Definitions | IBC 2009 | 2 |
| Masonry | IBC 2009 | 2 |
| High-piled Combustible Storage | IFC 2009 | 2 |
| Fixtures, Faucets and Fixture Fittings | IPC 2009 | 2 |
6 further chapters mention the term.
The term in use
How the code actually writes about backing, quoted from the 2009 text hosted here:
Backing or a lath shall provide sufficient rigidity to permit plaster applications.
Wood framing supporting gypsum board shall not be less than 2 inches (51 mm) nominal thickness in the least dimension except that wood furring strips not less than 1-inch-by-2 inch (25 mm by 51 mm) nominal dimension may be used over solid backing or framing spaced not more than 24 inches (610 mm) on center.
The backing of anchored and adhered veneer shall be of concrete, masonry, steel framing or wood framing.
The terms backing 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 backing covers:
- Veneer — IBC 2009: A facing attached to a wall for the purpose of providing ornamentation, protection or insulation, but not counted as adding strength to the wall.
Backing: what to open, and in what order
Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.
| Check | Where | Confirmed |
|---|---|---|
| Read the definition in the adopted IBC | Exterior Walls | |
| Re-check the requirement that uses it | Gypsum Board and Plaster (IBC 2009) | |
| Re-check the requirement that uses it | Wall Covering (IRC 2009) | |
| Re-check the requirement that uses it | Exterior Walls (IBC 2009) | |
| Re-check the requirement that uses it | Wall Construction (IRC 2009) | |
| Confirm the dependent definition | Veneer | |
| 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
- Veneer: Building Code Definition
- Exterior Wall: Building Code Definition
- Water-resistive Barrier: Building Code Definition
- Exterior Wall Covering: Building Code Definition
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 publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.
Source links
Frequently asked questions
What is the code definition of backing?
The International Building Code (IBC) 2009 defines it in Exterior Walls as: “The wall or surface to which the veneer is secured.” 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 backing?
In this corpus the term is used across 18 chapters, led by Gypsum Board and Plaster 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 are the different types of building codes?
Building is a separate defined term. The IBC 2009 defines it as: “Any structure used or intended for supporting or sheltering any use or occupancy.” That is not the same as backing, which the IBC 2009 defines as “The wall or surface to which the veneer is secured.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
What does "backing" mean?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IBC 2009 states, in Exterior Walls: “The wall or surface to which the veneer is secured.” It is defined in IBC 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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