OBC 2024 Guide: Corridor Flame-Spread Ratings and Foamed Plastic Protection
Sarah's Expert Insight
OBC Compliance Specialist
"In the growing residential markets of London and Oakville, the proper encapsulation of foamed plastic is a frequent focal point during building inspections. At empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure that every corridor finish and insulation assembly exceeds these flame-spread requirements to guarantee both legal compliance and long-term fire safety for our clients."
Navigating the 2024 Building Code Compendium is a critical step for any commercial or multi-residential development. Section 9.10.17 provides specific mandates for interior finishes to ensure occupant safety during fire events.
Flame-Spread Ratings for Public Corridors
According to Article 9.10.17.5., wall surfaces in non-sprinklered public corridors must strictly adhere to flame-spread limits. Specifically, at least 90% of the total wall surface must have a rating of not more than 75, or the upper half of the walls must meet a more stringent rating of 25 or less.
Calculation and Occupancy Standards
When calculating these areas, Article 9.10.17.6. notes that skylights, glazing, and combustible doors are excluded. Furthermore, if a public corridor contains an occupancy, the interior finishes within that space must match the flame-spread requirements of the corridor itself to maintain a uniform safety profile.
Protection of Foamed Plastics in Wall and Ceiling Assemblies
Foamed plastics are excellent insulators but require robust protection under Article 9.10.17.10. These materials must be separated from the interior of the building by:
- Approved interior finishes (Subsections 9.29.4. to 9.29.9.).
- Sheet metal at least 0.38 mm thick with a melting point above 650°C (for non-Group C occupancies).
- A thermal barrier meeting the requirements of Sentence 3.1.5.15.(2).
Walk-in Coolers and Garage Doors
Specific exceptions exist for factory-assembled units. Walk-in coolers and freezers must be protected by sheet metal on both sides and contain no air spaces, while thermosetting foamed plastic in storage garage doors must be covered with metallic foil and meet specific flame-spread benchmarks.
For expert implementation of these safety standards, contact empcontracting.ca Inc. your construction contractor in London, Ontario.
Disclaimer: This content is generated from the Ontario Building Code for educational purposes. Always consult with a licensed professional engineer or your local building department before starting any construction project in London, Ontario.