National Building Code Standards for Interior Finishes and Flame-Spread Ratings
Understanding the safety regulations for interior finishes is critical for any commercial or residential project. At empcontracting.ca Inc. your construction contractor in London, Ontario, we prioritize compliance with the National Building Code of Canada (NBC) to ensure the safety and longevity of your build.
Section 3.1.13: Interior Finish Requirements
The NBC defines interior finishes as any material forming part of the interior surface of a building. This includes walls, partitions, ceilings, and even specific types of flooring and decorative elements. Compliance with Section 2.3 of Division B of the NFC is mandatory for these materials.
What Qualifies as an Interior Finish?
According to NBC 3.1.13.1, interior finish materials include:
- Interior cladding such as plaster, wood, or tile.
- Surfacing materials like fabric, paint, plastic, veneer, or wallpaper.
- Doors, windows, and decorative trim.
- Lighting elements, including diffusers and lenses in ceiling surfaces.
- Carpet material overlying a floor not intended as the finished floor.
Flame-Spread Rating Standards (NBC 3.1.13.2)
The flame-spread rating is a measure of how quickly fire can spread across the surface of a material. For most interior wall and ceiling finishes, the rating must not exceed 150. However, specific occupancies and locations require much stricter limits.
Table 3.1.13.2: Maximum Flame-Spread Ratings
The following table outlines the requirements for various occupancy types and locations, distinguishing between sprinklered and non-sprinklered buildings:
| Occupancy, Location, or Element | Sprinklered | Not Sprinklered |
|---|---|---|
| Group A, Division 1 (Doors, Skylights, Glazing) | 150 | 75 |
| Group B Occupancies | 150 | 75 |
| Exits | 25 | 25 |
| Lobbies (per Sentence 3.4.4.2.(2)) | 25 | 25 |
| Vertical Service Spaces | 25 | 25 |
Exceptions and Special Provisions
The code allows for certain flexibility regarding doors and small surface areas:
- Doors: Most doors (excluding Group A, Div 1) can have a flame-spread rating of up to 200. Doors within dwelling units are generally exempt from these specific rating requirements.
- Surface Area Allowances: Up to 10% of the total wall and ceiling area may exceed the required rating, provided those sections do not exceed a rating of 150. For specific lobbies, this allowance increases to 25% of the wall area.
When planning your next project, trust the experts who know the code inside and out. Contact empcontracting.ca Inc. your construction contractor in London, Ontario, for professional guidance and high-standard installations.