National Building Code Standards for Combustible Finishes and Insulation in Noncombustible Construction
Understanding the National Building Code of Canada (NBC) is essential for ensuring safety and compliance in modern architecture. At empcontracting.ca Inc. your construction contractor in London, Ontario, we prioritize these safety regulations to deliver high-quality, code-compliant structures for our clients.
Section 3.1.5.13: Combustible Interior Ceiling Finishes and Gypsum Board
In buildings required to be of noncombustible construction, the use of combustible interior ceiling finishes is strictly regulated to mitigate fire risks. According to Division B, Sentence (3), finishes other than foamed plastics are permitted if they are no more than 25 mm thick and maintain a flame-spread rating (FSR) of 25 or less.
Exceptions for Flame-Spread Ratings
The code allows for minor exceptions where up to 10% of the ceiling area within a fire compartment may have a flame-spread rating of up to 150. Additionally, fire-retardant-treated wood is permitted provided it meets specific thickness requirements or consists of exposed wood battens.
Standardizing Gypsum Board Usage
Gypsum board is a critical component in noncombustible construction. To remain compliant, gypsum board must have a tightly adhered facer not exceeding 1 mm in thickness and a surface flame-spread rating of no more than 25. As your construction contractor in London, Ontario, empcontracting.ca Inc. ensures all interior finishes meet these exact specifications.
Section 3.1.5.14: Standards for Combustible Insulation
Combustible insulation is permitted in noncombustible buildings under specific conditions, particularly regarding its placement and fire-rated protection.
Permitted Installation Locations
Insulation with a flame-spread rating of 25 or less is allowed on any exposed surface. Furthermore, combustible insulation is permitted in the following areas:
- Above roof decks
- Outside of foundation walls below ground level
- Beneath concrete slabs-on-ground
Thermal Barrier Protection
If the combustible insulation has a flame-spread rating between 25 and 500, it must be protected from the building's interior by an approved thermal barrier. According to Article 3.1.5.14, acceptable thermal barriers include:
- 12.7 mm thick gypsum board (mechanically fastened)
- Lath and plaster
- Masonry or concrete
Special Requirements for High-Rise Buildings
For buildings exceeding 18 meters in height that are not sprinklered, the code mandates even more stringent protection. Thermal barriers must meet CAN/ULC-S101 standards to ensure they do not exceed specific temperature rise thresholds during fire endurance tests. For expert guidance on these complex safety requirements, trust empcontracting.ca Inc. your construction contractor in London, Ontario, to handle your next commercial or residential project with precision and care.