2024 Ontario Building Code: Professional Guide to Stair Widths and Exterior Seals
Sarah's Expert Insight
OBC Compliance Specialist
"Mastering the 860mm versus 900mm width distinction is vital for modern renovations in London and Oakville, especially when integrating secondary suites. As empcontracting.ca Inc. your construction contractor in London, Ontario, we emphasize that proper alkali-resistant coatings on aluminum frames are often overlooked in Muskoka builds, yet they are essential for long-term structural integrity against the elements."
Compliance Standards for Stairs, Ramps, and Exterior Openings
Navigating the 2024 Ontario Building Code (OBC) is a critical step for any successful build. At empcontracting.ca Inc. your construction contractor in London, Ontario, we specialize in translating these technical requirements into high-quality residential and commercial structures.
Exterior Seals and Aluminum Protection
Per Subsection 9.27.4, it is mandatory to apply sealants between window frames or trim and the exterior cladding. Additionally, the OBC requires that all unfinished aluminum window, door, or skylight components in contact with masonry, concrete, or stucco be treated with an alkali-resistant coating. This prevents the corrosive reactions that can occur when aluminum meets cementitious materials.
General Application: Section 9.8
Section 9.8 governs the design and construction of interior and exterior stairs, ramps, landings, and guards. This includes specific mandates for garages serving single dwelling units or houses with secondary suites, ensuring they meet the same safety standards as interior living spaces.
OBC 9.8.2.1: Minimum Stair Width Requirements
Understanding width requirements is vital for both safety and code approval:
- Single Dwelling Units: Exit stairs and at least one stair between each floor level must maintain a minimum width of 860 mm.
- Public Residential Stairs: For larger residential buildings, the required width increases to 900 mm.
- Non-Residential Occupancy: Stairs must be at least 900 mm wide, or calculated at 8 mm per person based on the specific occupant load.
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.