By the Earthstone Materials Team · Published October 4, 2026 · Last updated: October 4, 2026
The short answer: dig a sloped trench, line it with fabric, bed perforated pipe in clean angular stone, wrap it shut, and give the water somewhere to go. The stone does two jobs: carrying water to the pipe and keeping soil away from it. Use clean angular stone, never limerock or dirt, and the drain keeps working for decades.
What you need
For a typical residential drain: drain rock or #57 stone (angular and washed), 4-inch perforated PVC or corrugated pipe, non-woven geotextile fabric, and coarse sand or soil for backfill. Pick the stone first: our best rock for a French drain guide explains why angular stone beats rounded, and the drainage rock guide covers sizing.
Step 1: Plan the route and the slope
Route the drain from the wet area to a legal outlet: a swale, a dry well, or the street drainage, never a neighbor’s lot. The trench needs fall along its whole length, about a 1 percent slope (roughly 1 inch of drop per 8 feet). In flat South Florida yards, that slope is the whole game: no fall, no flow.
Step 2: Dig the trench
A standard residential trench is 12 to 18 inches wide and 18 to 24 inches deep. Keep the bottom smooth and at a consistent slope; humps in the trench bottom become permanent puddles inside your drain. Call 811 before you dig.
Step 3: Line it with fabric
Lay geotextile fabric in the trench with plenty of excess on both sides. You will fold this over the top at the end like a burrito. The fabric is not optional: soil migrating into the stone is what kills French drains, and in sandy Florida soil it happens fast without a barrier.
Step 4: Stone, pipe, more stone
Spread several inches of stone in the bottom, set the perforated pipe on it with the holes facing down, then cover with stone on all sides: several inches below is not enough, the pipe needs stone above and alongside too. Keep a few inches of clearance between the top of the stone and the soil surface.
Step 5: Wrap, backfill, finish the outlet
Fold the fabric over the stone, then backfill with soil and sod or mulch over the top. At the outlet end, daylight the pipe with a pop-up emitter or into a swale, and armor the outlet with rip rap if water exits with force. Test with a hose before you backfill: water should run the full length and exit cleanly.
Mistakes that kill drains
Using limerock base or any stone with fines inside the trench: it seals itself within a season or two. Skipping the fabric. Burying the pipe with the holes up. And no outlet plan: a drain that ends in a low spot just moves the puddle. Stone is sold by the cubic yard; figure trench length by width by stone depth in feet, divide by 27, and request a quote with your measurements.