Fiber Cement Corrugated Sheet Calculator
Estimate non-asbestos fiber cement sheets for roofing. Calculates effective coverage with wave overlaps, corner mitre requirements, and structural weight loads.
About
Fiber cement sheets serve as the modern, safe alternative to traditional asbestos roofing, used widely in agricultural and industrial buildings. Due to their rigidity and weight, calculation involves more than just area coverage. It requires strict adherence to "wave" overlap rules to ensure structural integrity and weatherproofing.
This tool addresses the complexity of corner cutting (mitring). In fiber cement roofing, where four sheets meet at a corner, two must be mitred to prevent the buildup of four layers of thickness, which would crack the sheets when tightened. This calculator estimates the material load for truss analysis, providing the total weight in kilograms, a critical factor since fiber cement is significantly heavier than metal or bitumen alternatives.
Formulas
The total weight Wtotal exerted on the roof trusses is calculated by summing the weight of all sheets.
Where msheet is the mass of a single sheet, determined by its density and dimensions. The net width wnet depends on the overlap k (typically 70mm or one wave):
Reference Data
| Profile Type | Nominal Width (mm) | Net Cover Width (mm) | Weight (kg/m²) | Min Pitch |
|---|---|---|---|---|
| Standard 6 | 1086 | 1016 | 17.0 | 10° |
| Major 7 | 1000 | 930 | 16.5 | 15° |
| Modern 8 | 1050 | 980 | 21.0 | 15° |
| Big 6 (Reinforced) | 1086 | 1016 | 24.0 | 5° |