Snow Load Calculator Ontario

This snow load calculator helps engineers and builders determine the required snow load for structures in Ontario based on the Ontario Building Code. Proper snow load calculation is essential for structural safety and compliance with provincial regulations.

How to Use This Calculator

To calculate the snow load for your Ontario building:

Enter the building's roof pitch in degrees (0 for flat roofs)
Select the exposure category (sheltered, partially exposed, or fully exposed)
Enter the building's height in meters
Click "Calculate" to get the snow load in kPa

The calculator uses the Ontario Building Code (OBC) 1995 provisions for snow load determination. Results are based on the most current provincial standards.

Snow Load Basics

Snow load is the weight of snow that a structure must be designed to support. It's calculated based on:

Roof pitch - steeper roofs shed snow more easily
Exposure - buildings in open areas receive more snow
Building height - taller buildings require more snow load

Basic snow load formula:

Snow Load (kPa) = Ground Snow Load × Exposure Factor × Height Factor × Pitch Factor

The Ontario Building Code sets the ground snow load at 0.7 kPa for most regions, with adjustments for exposure and building characteristics.

Ontario-Specific Considerations

Ontario's snow load requirements are governed by the Ontario Building Code (OBC) 1995. Key factors include:

Factor	Description
Exposure	Sheltered (0.8), Partially Exposed (1.0), Fully Exposed (1.2)
Height	Adjustments for buildings over 15m
Pitch	Reductions for roofs steeper than 30°

Note: The Ontario Building Code requires snow load calculations for all buildings over 15m in height, regardless of exposure.

Calculation Method

The calculator uses the following step-by-step method:

Determine ground snow load (0.7 kPa for Ontario)
Apply exposure factor based on building location
Adjust for building height if over 15m
Apply roof pitch reduction if applicable

Example calculation for a 10° pitch, partially exposed building 20m tall:

Snow Load = 0.7 × 1.0 × 1.0 × 0.9 = 0.63 kPa

Design Considerations

When designing for snow load in Ontario, consider:

Local climate variations - some regions may have higher snow loads
Roof drainage systems - proper design prevents snow buildup
Live load combinations - snow loads often combine with other loads
Wind load interactions - snow and wind loads often act together

Always consult with a structural engineer for critical projects to ensure proper load calculations and building safety.

Frequently Asked Questions

What is the minimum snow load required in Ontario?: The minimum snow load in Ontario is 0.7 kPa, but this can be increased based on exposure and building characteristics.
How does roof pitch affect snow load?: Steeper roofs (greater than 30°) receive a reduction in snow load as snow slides off more easily.
Are there different snow load requirements for different Ontario regions?: While the base snow load is the same, local climate variations may require higher design values in some areas.
What is the difference between sheltered and exposed buildings?: Sheltered buildings have a 20% reduction in snow load, while fully exposed buildings have a 20% increase.
How often should snow load calculations be updated?: Snow load calculations should be reviewed whenever building designs change or when new building codes are adopted.