1. What is the USU Snow Load Equation?

The USU Snow Load Equation calculates the design snow load for roofs according to ASCE standards. It considers ground snow load adjusted for roof exposure, thermal conditions, and building importance.

2. How Does the Calculator Work?

The calculator uses the USU Snow Load equation:

Where:

• \( Pf \) — Flat roof snow load (psf)
• \( Ce \) — Exposure factor (dimensionless)
• \( Ct \) — Thermal factor (dimensionless)
• \( I \) — Importance factor (dimensionless)

Explanation: The equation adjusts the ground snow load for specific roof conditions and building characteristics.

3. Importance of Snow Load Calculation

Details: Accurate snow load calculation is crucial for structural design to prevent roof collapse while avoiding over-engineering and unnecessary costs.

4. Using the Calculator

Tips: Enter all required values. Pf is typically based on local building codes. Ce, Ct, and I factors are determined by roof characteristics and building use.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical Pf value?
A: Pf varies by location, ranging from 20 psf in mild climates to 70+ psf in heavy snow regions. Check local building codes.

Q2: How do I determine the exposure factor (Ce)?
A: Ce depends on roof exposure to wind. Typically 0.7-1.2 (higher for sheltered roofs, lower for exposed roofs).

Q3: What affects the thermal factor (Ct)?
A: Ct accounts for heat loss through the roof. Values range from 0.85 (cold roofs) to 1.2 (warm roofs with snow melting).

Q4: How is importance factor (I) determined?
A: I depends on building occupancy category. Higher for essential facilities (hospitals = 1.2), lower for agricultural buildings (0.8).

Q5: Does this account for snow drifts?
A: No, this calculates uniform snow load. Drift loads require additional calculations.