French drains and drain tile: what they do, who may install them, where the water goes

What drain tile does, and the order of fixes

Drain tile is perforated pipe set in coarse stone beside or on top of the footing, and the 2015 IRC (R405.1) calls for it, or an equivalent gravel or crushed-stone drain, around foundations that retain earth and enclose habitable or usable space below grade, discharging by gravity or mechanical means to an approved drainage system. It is a new-construction rule and does not by itself oblige the owner of an older home to add one, which is our reading.

University of Minnesota Extension, an out-of-state land-grant source, puts the order plainly: control interior moisture first, then correct grading, gutters and downspouts, and only then add an interior or exterior drainage system. Grade should slope away at least 1 inch per foot for at least 6 feet, and downspout extensions should discharge at least 4 feet from the wall.

The same source says an exterior drainage system at an existing building is the most costly but also the most effective approach, since it requires digging around the foundation, and that all exterior systems must drain to a sump with an airtight cover.

What drainage work costs: the evidence we can show

Our estimate for drainage work in Michigan is $2,375 to $18,400 per project, or $11 to $45 per linear foot, exterior French drain. Both are models, not quotes, built from published national ranges and adjusted by Michigan's construction laborer wage ratio (1.05); we have collected no Michigan quotes. The rows show what laborers are paid, which is not a price, and what some cities charge for the drain and sump lines on a plumbing permit.

How we estimate costs: the Estimated range row is a model, not a quote. It takes two published national ranges for this job (cost guides from third-party sites that we have not verified and do not cite) and multiplies them by Michigan's construction laborer median wage ratio to the US (1.05, BLS 2025 data read through O*NET OnLine). No permit fee is added: the city permit rows below are shown as printed. The wage and permit rows are what workers are paid and what a city's own schedule charges, and neither is a price. Your soil, water and the repair method move a real quote well outside any range, so get an independent diagnosis first. We have not collected quotes, and we found no Michigan foundation company that publishes a price we could count. Full method. Prices as of Oct 19, 2026.

How much water a roof sends to the wall

The extension's worked example: a 1-inch rain puts 1,250 gallons on the roof of a 2,000-square-foot house, and it recommends at least one downspout per 50 linear feet of eave. The Michigan State Police note that floods often follow snowmelt and heavy spring rain, and the National Weather Service recorded 4 to 6 inches of rain in about four hours over Wayne, southern Oakland and Macomb counties on August 11, 2014.

Where Michigan allows the water to go

EGLE's residential sump pump guidance (January 2022) calls discharge to the ground where it can infiltrate the preferred method, without erosion or ponding on neighbors, says a storm sewer connection needs permission from the owner or operator of that sewer, and does not recommend discharge to lakes, rivers, streams or wetlands. Floor drain discharges are not authorized.

Local rules add to that. Midland has barred footing drain connections to the sanitary sewer since 1987, Westland requires sump lines to end in a storm structure or dry well with an engineering permit for any storm connection, and Livonia's waterproofing checklist asks for an engineering permit and bond for work in the right of way or a storm sewer connection. Grand Rapids has paid up to $4,500 toward taking footing drains off the sanitary sewer, which we read through a summary, so confirm with the city.

Who may do the work, and the plumbing split

Exterior drain tile, French drains and regrading are excavation and improvement work, so a contractor taking $600 or more in labor and materials needs a LARA license with a matching craft (excavation, basement waterproofing or a residential builder license), which is our reading of MCL 339.2404. A pure yard drain may fall outside the statute's definition of a residential structure, which we could not settle.

A sump and its discharge piping are plumbing under Michigan's plumbing license law (MCL 339.6107), and city fee schedules list sumps as plumbing permit items. A waterproofing contractor holding only a maintenance and alteration license is not a plumber. Digging also triggers a MISS DIG notice, due at least 72 hours ahead (non-business hours excluded) and not more than 14 calendar days ahead. The timing is from a summary, so verify it with MISS DIG.

Check the cause before you buy a drain

A drainage contractor who finds water in your basement has an obvious answer to sell. That answer is often right, and it is also the most expensive one on the extension's list. Ask for the diagnosis in writing, ask what grading and gutter changes were considered first, and for anything that touches the wall or footing, ask an engineer rather than the installer. Where the wall itself is moving, see bowing walls.

When a drainage problem cannot wait

What to check before you call about drainage

1. Walk the outside during a rain and watch where roof water lands. Note any downspout that ends within a few feet of the wall.
2. Look at grade: does the ground slope toward the house?
3. Ask your city where a sump may discharge on your lot before you plan a drain.

Permits for drains and discharge

Michigan's building code requires a permit to alter or repair a structure, and cities print different lines. Livonia, Dearborn and Warren name waterproofing; Westland lists interior subsoil drains and sump pits under plumbing; Livonia and Westland want an engineering permit for a storm sewer connection. Ask your own city, and ask the contractor who pulls the permit.

Ask for the contractor's license number and check it with your state licensing agency before you sign anything.

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Questions people ask

Keep reading

Guides

• Where a Michigan sump pump may discharge, and who may install one
• How to waterproof a basement without digging, and what that can and cannot fix
• Basement waterproofing permits in Michigan, city by city

Related services

• Basement waterproofing
• Sump pump
• Bowing walls

Michigan licensing, code and permit facts · How to check a builder's license · Report a wrong price or rule