How to choose a contractor to install a French drain

Start with the drainage problem, not the trench

If you are looking for a contractor to install French drain systems, the right hire is not simply the crew with a trencher. A credible contractor should first identify where the water is coming from, where it can legally discharge, and whether a French drain is the right tool for the site. On many properties, grading, gutters, swales, catch basins, sump pumps, waterproofing, or a combination of measures may be more appropriate than one buried pipe. The buying decision should be based on a defined scope: route, depth, pipe, aggregate, filter fabric, slope, outlet, utility marking, restoration, and maintenance access.

A French drain is useful when water needs to be collected below the surface and carried to a safe outlet. It is less useful when the underlying problem is roof runoff dumping at the foundation, settled soil sloping toward the house, a blocked storm line, or water entering through cracks that require waterproofing and repair. The U.S. EPA’s moisture guidance emphasizes fixing leaks and seepage and keeping ground sloped away from the house. The Building America Solution Center also treats site grading, swales, drains, gutters, and downspouts as parts of one water-management strategy.

For owners, builders, and procurement teams comparing local contractors, the goal is not to buy the lowest per-foot number. It is to source a scope that can be inspected, maintained, and matched to site conditions. For more contractor-selection topics in construction sourcing, see the Sourcing section.

Match the contractor type to the French drain you actually need

Different contractors use the term French drain for different systems. A shallow yard drain that relieves soggy turf is not the same as a footing drain beside a basement wall. Before requesting bids, define the setting and the risk level.

A general landscaper may be sufficient for a simple curtain drain in an open yard. Foundation-adjacent excavation is different because the work can affect soil support, waterproofing, utilities, and basement moisture risk. If the drain will be deep, close to a footing, tied into a sump, or connected to municipal storm infrastructure, look for a contractor with documented experience in that specific type of work.

What a professional French drain scope should include

A complete proposal should describe the system well enough that another qualified person could understand it without a sales explanation. If a bid only says “install French drain,” it is too vague.

At minimum, ask for these items in writing:

• Drain purpose, such as intercepting uphill groundwater, reducing yard ponding, or relieving hydrostatic pressure near a foundation.
• Layout drawing or marked route showing inlet area, pipe run, cleanouts, outlet, and any areas to be restored.
• Planned trench depth and width, including how the contractor will maintain slope to the outlet.
• Pipe type and diameter, including whether it is perforated or solid in each section.
• Aggregate specification, such as clean washed stone rather than soil-contaminated fill.
• Filter fabric placement around the stone and pipe, not just a fabric sock used as a substitute for proper bedding where the design requires more.
• Discharge method, such as daylighting to a lower grade, drywell, approved storm connection, sump basin, or other permitted outlet.
• Cleanouts or inspection points so the system can be flushed or checked later.
• Handling of downspouts, surface drains, and roof runoff.
• Backfill, compaction, topsoil, sod, mulch, pavement patching, and erosion protection at the outlet.

The Building America Solution Center describes a typical French drain as a perforated pipe wrapped in rock and landscape fabric, with positive slope toward a drain outlet. Its guidance also notes that smooth PVC is generally less prone to sediment collection than corrugated pipe. These details do not create one universal design, but they help distinguish a planned drainage assembly from a gravel-filled trench with uncertain performance.

Foundation drains require a higher standard

When a French drain is intended to protect a basement or below-grade usable space, the conversation should move from landscaping to foundation drainage. The International Residential Code, as adopted and amended by local jurisdictions, contains foundation drainage provisions in Section R405. In general terms, the IRC requires drains around concrete or masonry foundations that retain earth and enclose habitable or usable below-grade space, unless the foundation is installed in well-drained soil conditions that meet the code exception. It also addresses placement near the footing, filter membrane, washed gravel or crushed rock, and discharge to an approved drainage system.

Local code controls the final requirement, so a contractor should not rely on a generic internet detail. Ask what code edition applies in your city or county, whether a permit is required, and whether the project needs inspection before backfilling. A foundation drain is often paired with dampproofing, waterproofing membrane, drainage board, or sump equipment. If the wall is cracked, bowed, settling, or showing structural movement, drainage alone is not a structural repair.

A shallow exterior yard drain should not be sold as a substitute for a footing-level drainage system. Likewise, an interior basement drain may manage water that has already reached the slab edge, but it does not correct exterior grading or roof runoff by itself. A responsible contractor should explain what the proposed system will and will not solve.

Permits, utilities, and excavation safety are part of the bid

In the United States, excavation planning should include 811 utility notification before digging. The federal Pipeline and Hazardous Materials Safety Administration describes 811 as the nationwide call-before-you-dig number, while state rules set lead times and responsibilities. Many states require notification a set number of business days before excavation. If you hire a contractor, confirm who files the ticket and ask for the ticket number before work starts.

Utility marking is not the entire risk picture. 811 systems generally coordinate with member utility owners, but private lines may not be marked. Irrigation, landscape lighting, pool utilities, private gas lines to grills, detached-garage power, and some water or sewer laterals may require a private utility locator. A good contractor asks about these conditions before bringing in a trencher or mini-excavator.

Excavation safety also matters. OSHA trenching guidance states that cave-ins are a primary hazard and that trenches five feet deep or greater generally require a protective system unless the excavation is entirely in stable rock. Shallower excavations can still be hazardous if soil is unstable, saturated, previously disturbed, or loaded by nearby equipment. Homeowners are not expected to manage a contractor’s safety program, but a bid for deep drainage work should not ignore shoring, sloping, spoil placement, access, and keeping heavy equipment away from trench edges.

How to compare estimates without buying the wrong system

French drain pricing varies widely because the same phrase can describe a shallow lawn trench, a deep exterior foundation excavation, or an interior basement drainage and sump system. Consumer cost guides published in 2026 commonly show broad ranges: shallow exterior yard drains may be quoted by the linear foot at the lower end, while deep foundation work, interior basement systems, sump pumps, pavement cuts, hauling, tight access, and restoration can push pricing much higher. See also: Membranes.

Use those numbers only as a screening tool. A $30-per-foot bid and a $90-per-foot bid may not describe the same system. The lower bid may exclude cleanouts, proper outlet construction, utility locating, hardscape repair, or adequate stone. The higher bid may include deeper excavation, waterproofing, sump equipment, or difficult access. Comparing totals without comparing scope often rewards the least-detailed proposal.

Ask each contractor to separate line items where practical:

• Mobilization and equipment access.
• Excavation and haul-off.
• Pipe, stone, fabric, fittings, catch basins, and cleanouts.
• Drywell, sump, daylight outlet, or storm connection.
• Foundation waterproofing or wall preparation, if included.
• Permits, inspections, and utility locating.
• Landscape, concrete, paver, or asphalt restoration.
• Warranty terms and maintenance exclusions.

A detailed estimate also helps you negotiate intelligently. If three contractors propose different routes or outlets, ask them to explain the reasoning. The best value is usually the scope that makes drainage sense, can be maintained, and clearly assigns responsibility for site restoration and code compliance.

Questions to ask before hiring a French drain contractor

Use the interview to test whether the contractor understands drainage design or is simply pricing trench footage.

• What evidence shows that a French drain is the right solution for this water problem?
• Where will the collected water discharge, and is that discharge allowed locally?
• How will you maintain slope from the collection area to the outlet?
• Will any sections use solid pipe instead of perforated pipe, especially for roof runoff or discharge runs?
• What pipe, stone, and filter fabric will be used?
• Will the system include cleanouts or inspection points?
• Who is responsible for 811 notification and private utility locating?
• Will the work require a permit, stormwater approval, or inspection?
• How will the trench be protected if it is deep or near the foundation?
• What exactly is excluded from the price?

The answers should be specific. “We always do it this way” is not a design explanation. Look for contractors who can discuss slope, soil, runoff source, discharge constraints, and maintenance access in plain language.

Red flags in French drain proposals

Some warning signs are technical; others are contractual. Treat the following as reasons to slow down, ask for clarification, or get another estimate:

• No written route, outlet, depth, or material specification.
• No plan for where water will go after it enters the pipe.
• A proposal to dump water onto a neighbor’s property, sidewalk, or unstable slope.
• Perforated pipe used for every section, including runs that should simply carry water away.
• No filter fabric or unclear fabric placement in soil that can migrate into the stone.
• No cleanouts on a long or buried system.
• A promise that the drain will solve basement leakage without evaluating wall cracks, grading, gutters, sump capacity, or waterproofing.
• No discussion of 811, private utilities, permits, or trench safety.
• A warranty that sounds broad but excludes clogging, settlement, outlet blockage, and lack of maintenance.

A French drain is hidden after installation, so errors are expensive to find later. The most valuable contractor is often the one who identifies limitations before digging.

Frequently asked questions

Do I need a landscaper, plumber, or foundation contractor?

For a shallow yard drainage issue, a landscape drainage or sitework contractor may be appropriate. For basement seepage, footing drains, sump systems, or excavation near the foundation, look for a foundation waterproofing or basement drainage contractor. If the project changes stormwater flow across property lines or involves steep slopes, retaining walls, or unusual soil conditions, involve an engineer.

Can a contractor connect downspouts to a French drain?

Sometimes, but it should be designed carefully. Roof runoff can overwhelm a perforated French drain and keep soil near the foundation wet if handled poorly. Many designs use solid pipe to carry downspout water away and reserve perforated pipe for groundwater collection. Local stormwater rules may also limit where roof water can discharge.

How long does installation usually take?

A simple, accessible yard drain may take one to three working days. Deep exterior foundation excavation, interior basement drainage, pavement removal, utility conflicts, wet soil, inspections, and restoration can extend the schedule. Weather can also delay excavation and backfill.

Should I ask for multiple bids?

Yes, but compare design assumptions, not just price. A useful bid should define the route, depth, materials, outlet, permitting, utility locating, restoration, and warranty. If estimates differ greatly, ask each contractor to explain what problem their design solves and what risks remain.

Will a French drain eliminate all water problems?

No. A French drain can collect and redirect certain subsurface or surface water, but it cannot repair structural cracks, replace proper grading, fix failed gutters, or make an illegal discharge acceptable. The most reliable projects treat drainage as one part of a broader water-management plan.