OBC 2024 Snow Load Requirements for Sloped Roof Valleys | empcontracting.ca Inc.
Sarah's Expert Insight
OBC Compliance Specialist
"In regions like London and Muskoka, heavy snow accumulation in roof valleys can compromise structural integrity if Ca values aren't strictly calculated to account for drifting. As a senior consultant at empcontracting.ca Inc., I ensure these Case III calculations are integrated into every design to prevent ice damming and structural failure during harsh Ontario winters."
Understanding the 2024 Building Code Compendium is essential for safe structural design. Section 4.1.6.12 details the specific calculations required for snow loads in the valleys of sloped or curved roofs. When working with empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure every roof design accounts for these complex variables.
Calculating Snow Load Coefficients (Ca) for Case III
In Case III scenarios, the accumulation of snow in roof valleys is determined by the horizontal distance from the bottom of the valley (x) and the total span between the peak and the valley (b/2). These calculations prevent structural failure by accounting for uneven snow drifting.
Calculation Formulas for Valley Load Accumulation:
- For 0 < x ≤ b/8: The coefficient Ca is calculated as 1.5 times Cb.
- For b/8 < x ≤ b/2: The coefficient Ca is calculated as 0.5 times Cb.
Key Variables and Standardized Factors
To maintain structural compliance across Ontario, the following notes from Figure 4.1.6.12 must be applied to ensure safety during heavy winter events:
- Wind Exposure Factor (Cw): Fixed at 1.0, as per Sentence 4.1.6.2.(3).
- Slope Factor (Cs): Fixed at 1.0, as per Sentence 4.1.6.2.(7).
By strictly adhering to these Part 4 structural requirements, we protect buildings from the unique environmental stresses found in the London and Oakville regions.
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.