{
  "slug": "french-drain-installation-cost",
  "title": "French Drain Installation Cost Calculator",
  "heading": "French Drain Installation Cost Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/french-drain-installation-cost",
  "summary": "Trenching, pipe, gravel, and fabric costs per linear foot of drain.",
  "description": "A French drain moves surface and groundwater away from a foundation or low spot using a perforated pipe bedded in gravel and wrapped in filter fabric inside a sloped trench. Cost scales almost entirely with linear footage, since trenching labor is the dominant cost driver, followed by pipe, gravel backfill, and fabric material. 2026 US national averages run roughly $10-$25 per linear foot for a standard interior or shallow exterior French drain, with deep exterior drains along a foundation running $25-$50 per foot due to more extensive excavation and often the need to daylight to a discharge point or connect to a sump pit. This calculator multiplies your linear footage by a combined material rate and adds trenching labor, then flags a pop-up emitter or sump connection cost if selected. Get a soil test or contractor site visit before finalizing a French drain plan — rocky or clay-heavy soil can significantly increase trenching labor time and therefore total cost.",
  "formula": "Total = (Linear Ft × (Pipe+Gravel+Fabric Rate)) + (Linear Ft × Trenching Labor Rate) + Outlet Cost.",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=french-drain-installation-cost",
  "inputs": [
    {
      "id": "lengthFt",
      "label": "Drain length",
      "kind": "number",
      "hint": null,
      "default": 60,
      "unit": "linear ft",
      "min": 10,
      "max": 400
    },
    {
      "id": "materialRate",
      "label": "Pipe, gravel & fabric rate",
      "kind": "number",
      "hint": null,
      "default": 9,
      "unit": "$/ft",
      "min": 4,
      "max": 20
    },
    {
      "id": "laborRate",
      "label": "Trenching labor rate",
      "kind": "number",
      "hint": null,
      "default": 14,
      "unit": "$/ft",
      "min": 5,
      "max": 35
    },
    {
      "id": "outlet",
      "label": "Discharge outlet type",
      "kind": "select",
      "hint": null,
      "default": "popup",
      "options": [
        {
          "value": "popup",
          "label": "Pop-up emitter — +$150"
        },
        {
          "value": "sump",
          "label": "Tie into sump pit — +$450"
        },
        {
          "value": "daylight",
          "label": "Daylight to grade — +$50"
        }
      ]
    }
  ],
  "outputs": [
    {
      "id": "totalCost",
      "label": "Total drain cost",
      "format": "currency",
      "hint": null,
      "primary": true
    },
    {
      "id": "laborCost",
      "label": "Trenching labor",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "outletCost",
      "label": "Discharge outlet cost",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "perFoot",
      "label": "All-in cost per linear foot",
      "format": "currency",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Drain length: 60 linear ft",
      "Pipe, gravel & fabric rate: 9 $/ft",
      "Trenching labor rate: 14 $/ft",
      "Discharge outlet type: Pop-up emitter — +$150"
    ],
    "outputs": [
      "Total drain cost: $1,530",
      "Trenching labor: $840",
      "Discharge outlet cost: $150",
      "All-in cost per linear foot: $25.50"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter drain length (linear ft).",
      "Enter pipe, gravel & fabric rate ($/ft).",
      "Enter trenching labor rate ($/ft).",
      "Enter discharge outlet type.",
      "Read your total drain cost on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "lengthFt": 35,
        "materialRate": 5.3999999999999995,
        "laborRate": 8,
        "outlet": "popup"
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "lengthFt": 60,
        "materialRate": 9,
        "laborRate": 14,
        "outlet": "popup"
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "lengthFt": 95,
        "materialRate": 14.4,
        "laborRate": 22,
        "outlet": "popup"
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "French drain vs. sump pump — which do I need?",
      "a": "A French drain redirects water via gravity before it reaches the foundation, while a sump pump actively removes water that's already collected in a pit; many homes use both, with the drain feeding water to the pit for the pump to discharge."
    },
    {
      "q": "How deep does a French drain need to be?",
      "a": "Exterior foundation drains are typically dug alongside the footing, often 1-3 feet deep, while interior drains along a basement's perimeter are usually shallower. Depth depends on your local frost line and the source of the water problem."
    },
    {
      "q": "Does a French drain need ongoing maintenance?",
      "a": "Yes — the gravel and pipe can silt up over 10-15 years, especially without proper filter fabric, so periodic inspection of the outlet and occasional flushing helps the system keep working as designed."
    },
    {
      "q": "Can I install a French drain myself?",
      "a": "Simple surface drains for a small low spot are DIY-feasible, but foundation-adjacent French drains involve grading calculations and connection to existing drainage that most homeowners hire out to avoid redirecting water into, rather than away from, the foundation."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/sump-pump-installation-cost",
    "https://www.revenuelab.fyi/toolbox/crawl-space-encapsulation-cost",
    "https://www.revenuelab.fyi/toolbox/culvert-pipe-installation-cost"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — French Drain Installation Cost Calculator (https://www.revenuelab.fyi/toolbox/french-drain-installation-cost)"
}