Ontario Building Code Guide: Flame-Spread and Smoke Classification for Part 3 Buildings
Sarah's Expert Insight
OBC Compliance Specialist
"Navigating flame-spread and smoke classification requires extreme precision, especially in multi-unit residential projects in Oakville or high-density developments in London. At empcontracting.ca Inc. your construction contractor in London, Ontario, we frequently see how overlooked plumbing fixture SDC ratings can stall final inspections; ensuring these small details align with the sprinkler status of your building is the key to a seamless occupancy permit."
Understanding the fire safety requirements of the 2024 Ontario Building Code (OBC) is essential for any major commercial or multi-unit residential project. At empcontracting.ca Inc. your construction contractor in London, Ontario, we specialize in ensuring your build meets every detail of the Compendium.
Flame-Spread and Smoke Ratings for Exit Doors
According to OBC 3.1.13.7.(4), doors serving exit stairways, vestibules, or corridors not within a suite have specific exemptions. They do not need to meet the standard ratings if they maintain a flame-spread rating (FSR) of no more than 200 and a smoke developed classification (SDC) of no more than 300, provided the doors occupy less than 10% of the total wall area.
Plumbing Fixture Compliance
General Smoke Classification Standards
Subsection 3.2.6. buildings require plumbing fixtures to have an SDC of no more than 300. However, exemptions exist for sprinklered buildings outside of Group B occupancies. In Group C or Group B occupancies that are fully sprinklered, the SDC may increase to 500 if wall surfaces are kept below an SDC of 200.
Therapeutic Bathing Systems
Specialized therapeutic bathing systems in Group B occupancies are exempt from the standard SDC requirements provided the room is sprinklered and does not open directly into sleeping quarters.
Noncombustible Construction and Exits
In buildings where noncombustible construction is mandated, the flame-spread ratings apply to the entire surface of materials within an exit. This rigorous standard ensures that even if a material is cut, the interior remains compliant, though exceptions are made for doors and fire-retardant-treated wood in sprinklered environments.
Underground Walkways and Exterior Passageways
Underground Walkways
OBC 3.1.13.9 dictates that all interior wall and ceiling finishes in underground walkways must be noncombustible, with the sole exception of paint.
Exterior Exit Passageways
If an exterior passageway is the primary means of egress, wall and ceiling finishes (including soffits and guards) must have an FSR not exceeding 25. A minor allowance is permitted for up to 10% of the area to reach an FSR of 150.
Elevator Car Interior Standards
For safety within vertical transportation, elevator car walls and ceilings must have an FSR of no more than 75 and an SDC of no more than 450 across all surfaces, including floors. 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.