French Drains & DrainageConstruction

French Drain Trench Excavation, Gravel Tonnage, Perforated Pipe & Geotextile Estimator

Calculate sub-surface groundwater drainage trench dimensions: washed crushed drainage stone tonnage, 4" perforated drain pipe, and non-woven geotextile filter fabric roll area.

Calculated Result

Total Washed Drainage Gravel (Metric Tons)

6.58tons

Calculator Inputs

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Total Washed Drainage Gravel (Metric Tons)

6.58tons

Non-Woven Geotextile Fabric Area (m²)

38.9 m²

Total Trench Excavation Volume (m³)

4.2 m³

Gravel Net Trench Volume

4.04 m³

Geotextile Rolls (50 m² ea)

1 rolls

French Drain Components Breakdown

Total Trench Excavation Volume (m³)
4.2 m³(39%)
Final Gravel Tonnage to Order
6.58 tons(61%)

Non-woven needle-punched geotextile fabric (4-6 oz) is mandatory to prevent fine silt from clogging the drainage gravel voids.

All engineering calculations, structural estimates, and electrical sizing metrics are provided for preliminary estimation only. Always ensure compliance with relevant statutory building codes and occupational safety standards, verified by a certified professional engineer before practical implementation.

Calculation Methodology

Gravel Volume = (Length * Width * Depth) - Pipe Volume. Gravel Weight (Tons) = Gravel Vol * 1.55 t/m³ * 1.05. Geotextile Area = Length * (Width + (2 * Depth) + 0.3m overlap).

Frequently Asked Questions

Perforations MUST face DOWN towards the trench bedding so rising groundwater enters the pipe at the lowest elevation and flows away efficiently.

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