DIY Material Cost
$293
Gravel
3.7 tons
Pipe
55 ft
DIY saves $957 – $2,707 in labor costs
| Application | Width | Depth | Pipe |
|---|---|---|---|
| Yard drainage | 6–12" | 12–18" | 3–4" |
| Foundation | 12–18" | 18–24" | 4" |
| Heavy clay soil | 18–24" | 24–36" | 4–6" |
| Driveway edge | 6–12" | 12–18" | 3–4" |
Inputs
Result
A 50-foot drain with standard 12" x 18" trench in loam soil costs $344 in DIY materials, versus $1,250–$3,000 professionally installed.
Inputs
Result
A 100-foot foundation drain in clay soil automatically sizes up to a 22.5" x 27.6" trench. DIY materials run $1,166, saving $1,334–$4,834 over professional installation.
A 50-foot French drain with a 12-inch wide, 18-inch deep trench needs about 1.4 tons (1.0 cubic yard) of gravel. The exact amount is the trench volume minus the pipe volume, multiplied by the gravel density of 1.4 tons per cubic yard. Use 3/4-inch crushed stone for best drainage.
| Drain Length | Trench (12" x 18") | Gravel Needed | Gravel Cost |
|---|---|---|---|
| 25 ft | 4.7 cu ft | 0.7 tons | $21–$35 |
| 50 ft | 9.4 cu ft | 1.4 tons | $42–$70 |
| 100 ft | 18.8 cu ft | 2.8 tons | $84–$140 |
DIY French drain costs run $5–$15 per linear foot for materials only. Professional installation costs $25–$60 per foot, including labor, excavation, and materials. Complex projects with deep clay soil or foundation work cost $50–$100+ per foot.
Yes, landscape fabric is essential for French drain longevity. The fabric wraps around the gravel to prevent soil particles from migrating in and clogging the system. Without fabric, a French drain can fail within 3–5 years. With fabric, it lasts 15–25 years.
Standard French drains are 18–24 inches deep. Yard drainage only needs 12–18 inches. Foundation drains should be at least as deep as the footing, typically 24–36 inches. Clay soil requires 15% deeper than standard to maintain adequate flow.
A 4-inch perforated pipe is standard for most residential French drains. Use 3-inch for light yard drainage. Use 6-inch for heavy water flow, clay soil, or commercial applications. Always use rigid perforated pipe with filter sock — avoid corrugated pipe in clay soil.
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Last Updated: Mar 9, 2026
This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.