French Drain Installation in McKinney, TX

French drain installation McKinney homeowners ask about is a gravel-filled trench with a perforated pipe at the bottom that collects water moving through the soil and carries it away from the foundation. The pipe is perforated, meaning it has small holes along its length so water in the surrounding gravel can enter it, and the trench slopes so the water runs downhill to an outlet. In McKinney the usual job is an exterior drain along the side of a slab house where water pools after rain, or around a pier and beam house whose crawl space floods. It is not the interior basement system the national guides spend most of their pages on, because McKinney homes do not have basements.

If one side of your house stays wet for days after a storm, call (972) 555-0100. A crew lead will walk the lot, check the fall to the street with a level (the fall is the slope that lets water run), and put the trench route, the outlet and the numbers in a free written estimate.

Signs you need French drain installation in McKinney

• Water standing against the slab or the brick for a day or more after rain
• A strip of lawn along one wall that stays soggy while the rest of the yard dries
• Water running toward the house from a neighbor’s higher lot or from a downspout with no extension
• Mulch and soil washed out of the beds along the foundation after every storm
• A crawl space that fills with water, or a patio slab that sinks on the wet side
• Stair-step cracks in the brick on the side that stays wet, with a dry, cracked side opposite

Why drainage matters on McKinney clay

The USDA NRCS describes the Houston Black series under McKinney as 40 to 60 percent clay with very high shrink-swell potential, and notes in its state soil fact sheet that this behavior is commonly a limitation for building sites in metropolitan areas. The same fact sheet explains that water enters the soil rapidly when it is dry and cracked and very slowly when it is moist. A slab on clay that is wet on the north side and dry on the south side is sitting on soil that is swelling on one side and shrinking on the other, and it tilts. The National Weather Service normals give DFW Airport 37.01 inches of rain a year, but 2011 brought 25.88 inches, 2015 brought 62.61, and the summer of 2023 delivered just 1.25 inches from June through August. A French drain does not change the weather. It keeps the wet side from staying wet, so both sides of the house see the same soil moisture. Foundation watering does the same job from the other direction in a drought.

What French drain installation involves in McKinney

Day one starts with layout. The crew marks the trench route along the wet side of the house, finds the outlet, and checks the fall with a level, because a drain with no slope is a pond. The trench is cut, lined with filter fabric to keep clay from silting up the gravel, and a bed of gravel goes in. The perforated pipe is laid with the holes facing down so water rises into it from below instead of washing silt in from above, then more gravel covers it and the fabric is folded over the top. Downspouts can be tied in through solid pipe and catch basins, which are small boxes with grates that take surface water. The trench is backfilled and the sod replaced. On a sloped lot the outlet is the street, the curb, a swale or a pop-up emitter in the lawn. On a flat lot the drain ends at a basin with a sump pump that lifts the water out.

On permits, the City of McKinney Building Inspections guidelines require a permit for foundation leveling, pier or footing replacement, shimming or floor system replacement, and a yard drain on its own is not on that list, though a drain built as part of a permitted pier job goes on the engineer’s drawings. Outside city limits, including any city’s ETJ, Collin County Development Services requires a Development Permit for work that disturbs the ground on a parcel.

French drain installation McKinney cost ranges

Two guides price this work and they disagree for a reason worth knowing. This Old House’s 2026 guide puts a French drain at $2,800 to $6,500, or $10 to $100 per linear foot, which fits an exterior drain along a McKinney slab. HomeAdvisor’s 2026 guide shows a $9,250 national average inside a $500 to $18,000 range, but that average is pulled up by interior basement perimeter systems at $40 to $100 per linear foot. HomeAdvisor’s own exterior perimeter drain, at $10 to $50 per linear foot or $500 to $10,000 total, and its curtain drain at $10 to $25 per linear foot, land close to This Old House. For McKinney homes without basements, the exterior figures are the ones to use.

Your written estimate lists the linear feet, the outlet and the sod repair as separate lines.

Related services

A French drain is one part of a foundation drainage plan that also covers grading, gutters and downspout extensions, and those cheaper fixes come first. Where the lot has no fall, the drain pairs with sump pump installation. In a drought the opposite problem shows up, and foundation watering keeps the dry side from shrinking away from the slab. If the wet side has already dropped and cracks have opened, the drain still goes in, but the lift is a slab foundation repair job with piers, and a foundation inspection is where that gets sorted out.

French drain installation McKinney lots need is a straightforward trench when the fall to the street is there and a pump job when it is not, and either way it starts with someone checking the slope with a level instead of guessing. Estimates are free and written, crews are insured, and every job carries a written warranty. Call (972) 555-0100 or request a free estimate online.