Trench Drain Installation McDonough

When a Driveway Needs a Trench Drain

Trench drain installation puts a long, narrow channel with a grate across a paved surface so water flowing down it drops into the channel and gets piped away. In McDonough the most common case is a garage that sits at the bottom of a sloped driveway, where every storm pushes a sheet of water under the door.

The key word is sheet. Water moving across concrete or asphalt spreads the full width of the surface, so a round grate in one spot catches only a slice of it. A channel set perpendicular to the flow intercepts the whole width. That's the job a trench drain does better than a catch basin, and it's why the two are often used together: the channel collects, the basin receives and sends it on.

Other spots that call for one: the edge of a patio that slopes toward the house, a walkway that funnels yard runoff to the front door, and the line where a neighbor's higher driveway sheds onto yours.

Cast iron trench drain grate running across a paved driveway entrance between asphalt sections — A grated channel running the full width of a paved entrance. Water flowing down the slope has to cross it, so none slips past the ends.

Trench Drain Installation Cost in McDonough

A residential driveway trench drain typically costs $400 to $2,500 installed, according to WSC Drainage's 2026 guide, which puts installed pricing at roughly $10 to $85 per linear foot. Channel material moves the number more than anything else, as the same guide's material-only prices show.

Channel and grate type	Materials per linear foot
Plastic channel, plastic grate	$5 to $16
Polymer concrete channel	$25 to $55
Galvanized steel	$30 to $120
Stainless steel	$50 to $160 and up

Source: WSC Drainage, channel drain installation cost guide (2026). Labor drivers on a Henry County job are saw-cutting and breaking out existing concrete, the pipe run from the channel to a legal outlet, and whether a catch box is needed at the low end. Solid 4-inch pipe for that run costs about $3.50 to $6 per foot in Metro Atlanta, per RW Lawn Co.

Choosing a Grate That Survives a Car

A driveway grate should carry at least an EN 1433 Class B125 rating, the class meant for private cars and car parks. The European EN 1433 standard grades channel drains by the force each one is tested at in kilonewtons: A15 for pedestrian and bike areas, B125 for driveways and parking, C250 for curbside and road shoulder use. Many US drain makers publish their grates on that scale.

Cheap plastic grates sold for patios are often only A15. Under a car's tire they flex, crack and pop out of the channel, and a broken grate across a driveway is a tripping hazard. Spending more on the grate is better value than spending more on the channel, since the channel sits in concrete and the grate takes every hit.

Example project

Garage at the foot of a sloped driveway in a newer McDonough subdivision

Setting: a front-entry garage below street level on a 16-foot-wide concrete drive. In summer storms, water crosses the apron and wets the garage floor.

Likely fix: 16 feet of B125-rated channel cut in at the garage threshold, tied to a catch box at one end, then about 40 feet of 4-inch solid pipe to a daylight point in the side yard.

Budget guide: WSC Drainage's $10 to $85 per installed foot puts the channel at about $160 to $1,360, and 40 feet of pipe materials adds about $140 to $240 at Metro Atlanta prices.

Watch-outs: any work in the strip near the street may sit in the public right of way, and the outlet must stay on this lot rather than spilling onto the neighbor's drive.

An illustrative example of a typical job, not a specific customer's project.

How a Driveway Trench Drain Is Installed

Trench drain installation in a new driveway: channel set between rebar mesh before the concrete pour — A channel drain set in place before a new driveway is poured. On new work it goes in with the slab; on an old driveway the slab has to be cut.

Plan the outlet. Decide where the channel empties and confirm the pipe can fall at least 1 percent from there to daylight or a basin.
Locate utilities. Request Georgia 811 at least three business days ahead; service lines often cross near the garage.
Cut and excavate. Saw-cut the slab on two parallel lines, remove the strip, and dig deep enough for the channel plus a concrete bed below it.
Set the channel. Join the sections, fit end caps and the outlet, and hold the top just under the finished surface so tires don't catch the edge.
Pour the surround. Encase the channel in concrete, then finish flush with the old slab on both sides.
Pipe and test. Run solid pipe to the outlet, flood the channel with a hose, and confirm water leaves before the grates go on.

Trench drain installation diagram for McDonough GA driveways: a trench drain feeding solid pipe to a catch basin and on to a daylight outlet — The usual layout: the channel across the driveway, solid pipe falling to a catch basin, then on to daylight.

On a new pour, the channel goes in with the slab, like the photo above. That costs far less than cutting in later, so anyone pouring a new driveway in Henry County should ask about adding one up front.

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Trench Drain Installation: FAQs

How much does a driveway trench drain cost? +

Most residential driveway trench drains come to about $400 to $2,500 installed, per WSC Drainage's 2026 pricing guide, with installed cost running roughly $10 to $85 per linear foot. Cutting out existing concrete, a long pipe run to the outlet and a heavier grate push a job toward the top of that range.

Is a trench drain the same as a french drain? +

No. A trench drain is a sealed channel with a grate that catches surface water running across pavement. A french drain is a buried perforated pipe in gravel that collects water moving through the soil. A driveway that floods in storms usually needs the first; a yard that stays wet between storms usually needs the second.

What load rating does a residential driveway grate need? +

Class B125 under the European EN 1433 standard is the usual pick for a home driveway, because it's rated for private cars and car parks. Class A15 is meant only for foot and bike traffic, so it belongs on patios and walks. The number is the test load in kilonewtons, so B125 is tested at 125 kN, roughly 28,000 pounds of force.

Do trench drains need to be sloped? +

Either the channel or its outlet has to fall. Some systems use pre-sloped sections that deepen toward the outlet, while neutral channels rely on depth and a short run to empty. Every system still needs solid pipe with steady fall from the outlet to a place the water can leave.

Can a trench drain go into an existing driveway? +

Yes. A strip is saw-cut across the slab, the concrete between the cuts is broken out, the channel is set on a concrete bed, and the strip is poured back flush around it. The patch will show, so many owners place the drain at a control joint or the garage threshold where a line already exists.

How do you keep a trench drain from clogging? +

Lift the grates and flush the channel a couple of times a year, and clear the catch box or outlet end where grit collects. Red clay washed off a landscaped bed is the usual culprit in Henry County, so stabilizing the bed above the driveway does as much as any cleaning schedule.