When a project calls for non-combustible trim or fire-rated exterior mouldings, the terms are easy to mix up, and the difference matters for your code path, your specification and your inspection. This guide explains what non-combustible actually means, how flame spread ratings work, and how to ask for fire-rated mouldings.
The short version: "Non-combustible" and "fire-rated" are not the same thing. Fire-rated options are available on request with a Class A fire rating (flame spread 25, smoke developed 110) that helps meet ASTM E-84 and UL 263. Ask us for the documentation for your project and we will confirm what applies. Contact our team.
What Does Non-Combustible Mean?
In building codes, a non-combustible material is one that does not ignite or add fuel to a fire when tested under a specific standard: ASTM E136 in the United States, or CAN/ULC-S114 in Canada. Typical examples of non-combustible materials are concrete, masonry, stone, steel and gypsum.
Non-combustible construction types in the codes are defined around these materials. When a drawing or specification says "non-combustible", it usually refers to this test, not to a general sense that a product is hard to burn.
What Does a Fire-Rated (Flame Spread) Moulding Mean?
Most trim, cladding and interior finish materials are classified by surface burning characteristics under ASTM E-84 (UL 723). The test measures how quickly flame travels across the surface and how much smoke develops. Results are grouped into classes:
| Class | Flame spread index | Smoke developed index |
|---|---|---|
| Class A (Class I) | 0 to 25 | 450 or less |
| Class B (Class II) | 26 to 75 | 450 or less |
| Class C (Class III) | 76 to 200 | 450 or less |
A Class A rating is the highest flame spread class. It is often required for finishes in corridors, exits and assembly spaces, and it is commonly requested for exterior trim on multi-family, hospitality and commercial buildings.
Where Fire-Rated Mouldings Are Used
- Exterior trim on multi-family and mixed-use buildings: window surrounds, sills, band mouldings and cornices on stucco and EIFS facades.
- Hospitality and commercial interiors: plaster crown mouldings, LED light coves and coffered ceiling beams in lobbies, corridors and restaurants.
- Retail and institutional facades where a Class A finish is specified.
Fire-Rated Mouldings from Mouldex
Mouldex mouldings combine a lightweight EPS foam core with a hard, inorganic cementitious coating reinforced with fiberglass mesh. Fire-rated options are available on request with a Class A fire rating (flame spread 25, smoke developed 110) that helps meet ASTM E-84 and UL 263.
Because code requirements depend on the construction type, the location of the trim on the building and your jurisdiction, confirm the required rating with your design professional or building official, then ask us for the matching documentation.
How to Specify Fire-Rated Trim
- Confirm the requirement. Check whether your code path calls for a non-combustible material or a flame spread class, and where on the building it applies.
- Choose your profiles. Select standard profiles from our exterior mouldings or interior mouldings, or send us a drawing for a custom profile.
- Request documentation. Ask for the fire rating documentation and product data for your submittal package.
- Order samples. A free sample kit lets you review the finish before you specify.
Frequently Asked Questions
Is non-combustible trim the same as Class A fire-rated trim?
No. Non-combustible refers to a material that passes ASTM E136 or CAN/ULC-S114. Class A refers to a flame spread index of 0 to 25 under ASTM E-84. A product can be Class A without being classified as non-combustible.
What fire rating do Mouldex mouldings have?
Fire-rated options are available on request with a Class A fire rating (flame spread 25, smoke developed 110) that helps meet ASTM E-84 and UL 263. Contact us for the documentation that applies to your project.
Can fire-rated mouldings be custom profiles?
Yes. Custom profiles are made from your drawings, photos or samples. Ask our team to confirm the fire-rated option and documentation for your custom profile.
Need fire-rated trim for a project? Send us your drawings and specifications and we will recommend profiles and provide the documentation for your submittal.
