Ice Load Calculator Form
The calculator uses a responsive input grid: three columns on large screens, two on smaller screens, and one on mobile.
Example Data Table
| Case | Unit | Thickness | Density | Area | Combined Factor Approx. | Design Pressure | Total Load |
|---|---|---|---|---|---|---|---|
| Small canopy | Metric | 20 mm | 900 kg/m³ | 24 m² | 1.05 | 0.185 kN/m² | 4.44 kN |
| Main roof bay | Metric | 25 mm | 900 kg/m³ | 48 m² | 1.25 | 0.276 kN/m² | 13.25 kN |
| Service platform | Imperial | 1.50 in | 57 pcf | 320 ft² | 1.18 | 8.41 psf | 2691.20 lb |
Formula Used
pbase = ρ × t × g / 1000
where ρ = density in kg/m³, t = thickness in meters, and g = 9.80665 m/s².
pbase = ρ × (t / 12)
where ρ = density in pcf and t = thickness in inches.
Cr = max(0.25, cos θ)
This simple reduction lowers retained ice load on steeper roofs while keeping a practical minimum factor.
pdesign = pbase × Cs × Ce × Ci × Ca × Cr
Cs = shape factor, Ce = exposure factor, Ci = importance factor, Ca = accumulation factor.
W = pdesign × A
A is tributary area in m² or ft².
This tool is for preliminary design checks and comparisons. Final structural design should follow the governing building code, project criteria, and licensed engineering judgment.
How to Use This Calculator
- Select metric or imperial units.
- Enter the average expected ice thickness.
- Input ice density for the likely winter condition.
- Enter the tributary roof or supported area.
- Add roof slope angle in degrees.
- Adjust shape, exposure, importance, and accumulation factors.
- Submit the form to see pressure, total load, and trend graph.
- Use the CSV or PDF buttons to save the result.
FAQs
1. What does this ice load calculator estimate?
It estimates base ice pressure, factor-adjusted design pressure, and total ice load over a tributary area. It also shows slope reduction, combined factors, conversions, and a pressure trend graph.
2. Which density should I use for ice?
Dense clear ice is often near 900 kg/m³, or roughly 57 pcf. Use local data, project criteria, or code guidance whenever available, especially for critical structures.
3. Why does roof slope reduce the result?
Steeper roofs tend to retain less uniform ice than flat roofs. This calculator applies a simple cosine-based reduction with a minimum floor, keeping the result conservative enough for quick preliminary studies.
4. What is the accumulation factor for?
It increases the load when local conditions create extra build-up, such as cold edges, drainage problems, drifting, or repeated freeze-thaw effects near equipment and parapets.
5. Can I use this for final code design?
Use it for screening, comparison, and early design decisions. Final code design should always follow the governing standard, project load combinations, site conditions, and professional engineering review.
6. What area should I enter?
Enter the tributary area supported by the member or roof zone you are checking. For a whole roof estimate, use the full loaded area.
7. Why are there both pressure and total load outputs?
Pressure helps compare loading intensity across cases, while total load shows the overall force acting on the selected area. Both are useful during structural sizing and checking.
8. What do the CSV and PDF buttons export?
They export the current result summary, including your main inputs, computed pressures, total load, factors, and notes. This makes documentation and quick reporting easier.