Shed Roof Snow Load Calculator
Every winter, thousands of cheap shed roofs collapse under heavy snow. Use this calculator to check the estimated snow load in your state and ensure your rafters are sized correctly.
Roof Specifications
Load Analysis
2x10+
Standard 2x4 shed trusses may fail.
Extreme snow load detected. Standard shed construction methods are not sufficient. Consult a structural engineer.
* New York has highly variable snow loads depending on elevation. Please verify the exact ground snow load with your local building department before construction.
Why Standard Shed Plans Fail in Winter
Many free shed plans you find online are designed by people in the South. They use 2x4 rafters spaced 24 inches on center. If you build that exact shed in Maine, Michigan, or Colorado, it will likely collapse during the first heavy snowstorm.
How Roof Pitch Affects Snow Load
A flat or low-slope roof holds all the snow that falls on it. A steeper roof sheds snow naturally. If you live in a high snow area, you should generally avoid lean-to style roofs unless you over-engineer the rafters significantly.
Metal roofing is also highly recommended in the North, as snow slides off metal much easier than asphalt shingles.
How to Strengthen Your Roof
If the calculator is warning you that 2x4s aren't enough, you have three options:
- Increase the Lumber Size: Upgrade from 2x4 to 2x6 rafters. (Recommended)
- Decrease the Spacing: Move your rafters closer together, from 24" On Center to 16" On Center.
- Increase the Pitch: A steeper roof sheds snow faster.
If you want peace of mind, consider using professional shed blueprints that include engineered truss designs specifically rated for northern climates.