Calculator Inputs
Example Data Table
| Scenario | Roof Area (m²) | Paver Size (mm) | Thickness (mm) | Density (kg/m³) | Additional Dead Load (kN/m²) | Estimated Paver Dead Load (kN/m²) |
|---|---|---|---|---|---|---|
| Residential terrace | 72 | 600 × 600 | 40 | 2300 | 0.40 | 0.91 |
| Pedestal roof deck | 216 | 600 × 600 | 50 | 2400 | 0.60 | 1.18 |
| Commercial amenity roof | 450 | 800 × 800 | 60 | 2450 | 0.75 | 1.47 |
Formula Used
Roof Area = Roof Length × Roof Width
Paver Area = Paver Length × Paver Width
Module Area = (Paver Length + Joint Spacing) × (Paver Width + Joint Spacing)
Unit Volume = Paver Area × Thickness
Unit Weight (kg) = Unit Volume × Concrete Density
Required Pavers = Ceiling(Roof Area ÷ Module Area)
Order Quantity = Ceiling(Required Pavers × (1 + Waste %))
Unit Weight (kN) = Unit Weight (kg) × 9.80665 ÷ 1000
Paver Dead Load = Unit Weight (kN) ÷ Module Area
Service Load = Paver Dead Load + Additional Dead Load + Live Load
Factored Load = Service Load × Safety Factor
Support Point Load = Unit Weight (kN) ÷ Supports per Paver
These equations estimate surface loading from concrete roof pavers. Final structural design should still be checked against code requirements, manufacturer data, and project-specific engineering assumptions.
How to Use This Calculator
- Enter the roof length and roof width in meters.
- Select the installation type that best matches your assembly.
- Provide paver length, width, thickness, and expected joint spacing.
- Enter concrete density for the paver material.
- Add a waste allowance for cutting, breakage, and layout losses.
- Include extra dead load from pedestals, bedding, grout, or accessories.
- Input the live load and safety factor used in your design review.
- Set the number of supports carrying one paver if point loads matter.
- Press Calculate Load to display results above the form.
- Use the CSV and PDF buttons to export the current calculation summary.
FAQs
1) What does this calculator estimate?
It estimates concrete roof paver weight, area-based dead load, service load, factored load, quantity, and approximate support point load. It helps compare finish options during early design, costing, or load review.
2) Why is joint spacing included?
Joint spacing affects the module footprint used for layout quantity and distributed load calculations. Wider joints reduce the solid paver area covering each module and change how many pieces fit the roof area.
3) Should I enter pedestal or bedding weight separately?
Yes. Use the additional dead load field for pedestals, bedding, adhesive, grout, mats, or other non-structural layers. This keeps the paver dead load separate from the rest of the roofing finish system.
4) Is the support point load enough for pedestal design?
No. It is only a simplified estimate based on paver self weight divided by supports. Real pedestal checks may require eccentricity, uplift, local bearing, movement joints, and concentrated service loads.
5) What density should I use for concrete pavers?
Normal-weight concrete is often near 2300 to 2450 kg/m³, but project data should come from the manufacturer or mix specification. Always use the actual product density when available.
6) Why are both service load and factored load shown?
Service load helps with practical load comparison and finish planning. Factored load applies your selected safety multiplier, giving a higher design-check value for conservative review and structural coordination.
7) Does the order quantity include waste?
Yes. The installed quantity is the net requirement before waste. The order quantity adds the waste percentage to cover cuts, handling damage, breakage, and layout inefficiencies during construction.
8) Can this replace a structural engineer’s review?
No. It is a planning and estimating tool. Final roof design must be checked by qualified professionals using structural drawings, loading codes, drainage requirements, membrane details, and manufacturer recommendations.