Building Code Glossary
Noncombustible Materials: Building Code Definition
How the IMC 2009 define noncombustible materials, 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
Noncombustible materials is a defined term in the International Mechanical Code (IMC) 2009, in Definitions. The code's own words are: “Materials that, when tested in accordance with ASTM E 136, have at least three of four specimens tested meeting all of the following criteria:” No other I-Code in this corpus defines it, so the IMC 2009 definition is the one to work from. The term is used in 33 chapters of this corpus, most often in Fire and Smoke Protection Features (IBC 2009), Special Detailed Requirements Based on Use and Occupancy (IBC 2009), Flammable Finishes (IFC 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?
Noncombustible Materials — IMC 2009, Definitions:
Materials that, when tested in accordance with ASTM E 136, have at least three of four specimens tested meeting all of the following criteria:
What must be verified before using this guidance?
Noncombustible Materials is defined once in this corpus, in the Definitions chapter of the International Mechanical Code (IMC) 2009:
Materials that, when tested in accordance with ASTM E 136, have at least three of four specimens tested meeting all of the following criteria:
Where noncombustible materials is used in the code
The term appears in 33 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 | IBC 2009 | 17 |
| Special Detailed Requirements Based on Use and Occupancy | IBC 2009 | 17 |
| Flammable Finishes | IFC 2009 | 15 |
| General Requirements | IFC 2009 | 12 |
| Motor Fuel-dispensing Facilities and Repair Garages | IFC 2009 | 11 |
| Interior Finishes | IBC 2009 | 9 |
| Building Planning | IRC 2009 | 6 |
| Foundations | IRC 2009 | 6 |
| Types of Construction | IBC 2009 | 5 |
| Definitions | IFC 2009 | 4 |
| Interior Finish, Decorative Materials and Furnishings | IFC 2009 | 4 |
| Flammable and Combustible Liquids | IFC 2009 | 3 |
21 further chapters mention the term.
The term in use
How the code actually writes about noncombustible materials, quoted from the 2009 text hosted here:
Materials having a structural base of noncombustible material as determined in accordance with Section 703.4.1 with a surfacing not more than 0.125 inch (3.18 mm) thick that has a flame spread index not greater than 50 when tested in accordance with ASTM E 84 or UL 723 shall be acceptable as noncombustible materials.
Lifts shall be permitted to be installed for use of employees only, provided they are completely enclosed by noncombustible materials.
Spray booths shall be constructed of approved noncombustible materials.
Noncombustible Materials: 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 IMC | Definitions | |
| Re-check the requirement that uses it | Fire and Smoke Protection Features (IBC 2009) | |
| Re-check the requirement that uses it | Special Detailed Requirements Based on Use and Occupancy (IBC 2009) | |
| Re-check the requirement that uses it | Flammable Finishes (IFC 2009) | |
| Re-check the requirement that uses it | General Requirements (IFC 2009) | |
| 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
- Building: Building Code Definition
- Construction Documents: Building Code Definition
- Registered Design Professional: Building Code Definition
- Dwelling Unit: 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 noncombustible materials?
The International Mechanical Code (IMC) 2009 defines it in Definitions as: “Materials that, when tested in accordance with ASTM E 136, have at least three of four specimens tested meeting all of the following criteria:” 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 noncombustible materials?
In this corpus the term is used across 33 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 the difference between combustible and noncombustible materials?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IMC 2009 states, in Definitions: “Materials that, when tested in accordance with ASTM E 136, have at least three of four specimens tested meeting all of the following criteria:” It is defined in IMC 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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