Add parallel runs for wide drainage areas or herringbone layouts.
The ground surface area draining into this system. Used to verify pipe capacity.
Depth of gravel above the pipe. More cover = better filtration and freeze protection.
Crushed stone (#57) is the standard. Pea gravel works but can migrate. Avoid pea gravel without a fabric trench liner.
12″ per 100 ft = 1% slope.
Typical: $150–$400/day rental or included in contractor rate.
Clay soils require heavier fabric to resist clogging. Strongly recommended for all installs.
3 oz: ~$0.60–$0.90/sq yd · 4 oz: ~$1.00–$1.50 · 6–8 oz: ~$1.50–$3.00.
Note: Avoid using both a fabric sleeve AND pea gravel — pea gravel migrates regardless. Use crushed stone with a sleeve.
Nylon sock: ~$0.30–$0.50/LF · Non-woven: ~$0.60–$1.00/LF · Pre-sleeved pipe adds ~$0.50–$1.50/LF to pipe cost.
Pop-up emitter: ~$8–$15 each. One per terminus. Day-lighted outlets on slope are most reliable.
Surface grate inlets that direct standing water into the French drain. ~$20–$60 per basin.
Recommended every 50–100 ft. Allows jetting and maintenance access. ~$15–$30 each.
One coupling needed per pipe joint (typically every 10 ft for 10-ft sticks). Pre-calculated below.
4″ SDR corrugated: ~$0.50–$0.90/LF · Perf PVC: ~$0.80–$1.40/LF.
Includes excavation, fabric, pipe, gravel, and backfill. Typical: $12–$30/LF. Clay soil, deep trench, or rock adds significantly.
Mini excavator day rental: ~$300–$500. Often included in contractor quote.
Gravel volume = trench cross-section minus pipe area × total LF · Liner sq yd = trench perimeter × LF ÷ 9 · Pipe capacity based on Manning's equation (n=0.013, half-full flow) · All quantities include 10% waste · Prices exclude tax and delivery