1. What is Flat Roof Snow Load?

The UK flat roof snow load calculation determines the expected snow load on a flat or nearly flat roof according to British standards (BS EN 1991-1-3). This is important for structural design and safety assessments.

2. How Does the Calculator Work?

The calculator uses the UK snow load formula:

Where:

• \( \mu_i \) — Shape coefficient (0.8 for flat roofs)
• \( C_e \) — Exposure factor (0.8 to 1.2)
• \( C_t \) — Thermal factor (0.8 to 1.1)
• \( s_k \) — Characteristic snow load (based on zone and altitude)

Explanation: The calculation considers geographic location, roof shape, exposure to wind, and thermal properties of the roof.

3. Importance of Snow Load Calculation

Details: Proper snow load calculation is essential for structural integrity, preventing roof collapse, and ensuring building safety during winter months.

4. Using the Calculator

Tips: Select your location's snow zone, roof type, enter altitude, and choose appropriate exposure and thermal factors. The calculator will provide the design snow load in kN/m².

5. Frequently Asked Questions (FAQ)

Q1: What are the UK snow zones?
A: The UK is divided into 3 zones: Zone 1 (South England, lowest snow), Zone 2 (Midlands, Wales), and Zone 3 (North England, Scotland, highest snow).

Q2: When is a roof considered flat?
A: In snow load calculations, roofs with pitch ≤5° are considered flat for snow accumulation purposes.

Q3: How does altitude affect snow load?
A: Snow load increases with altitude - approximately 0.1 kN/m² per 100m above 100m elevation.

Q4: What's the difference between sheltered and exposed?
A: Sheltered locations (Ce=0.8) have surrounding buildings/trees that reduce snow accumulation, while exposed locations (Ce=1.2) are open to wind and drifting.

Q5: Are there minimum snow load requirements?
A: Yes, most areas have a minimum design snow load of 0.6 kN/m² regardless of calculation results.