Preparing the ground for a driveway, excavation and drainage in Laval

Preparing the ground for a driveway means digging down to firm soil and giving water a way to drain off. Your driveway then shifts less with the frost. Next, you grade the bottom so it slopes away from the house. Where water pools, a drain laid in a stone-filled trench can collect it. National Asphalte prepares the ground this way.

Dig down to firm ground

Under the lawn or the old asphalt, the ground is not ready to carry a car. Topsoil holds water and settles over the years. Roots rot and leave empty pockets. Excavation removes these soft layers down to firm ground. The depth depends on the soil found on site and the vehicles that will drive on it. Before digging, you have the buried wires and pipes on the property located.

See excavation

Haul out the soil and the old surface

The excavator loads the soil and the old asphalt into trucks, which haul them off the property. Nothing that rots or settles should stay under the new driveway. It is the heaviest work on the job, and no one sees it once the driveway is finished.

Grade so the water drains away

Grading gives the bottom of the excavation its shape and slope. Water has to flow away from the house, toward the street or toward a spot meant to receive it. A driveway with no slope holds puddles, which turn to ice in winter. Grading also connects the driveway to the garage and the sidewalk, with no step or dip. You grade the bottom first, then each layer of stone laid on top.

See lot grading

Give the water a way out

Water that stays under a driveway ends up damaging it. In winter, this water freezes and lifts the surface. When it thaws, the wet ground softens and the surface sags. The slope solves a large part of the problem. On flat land or in soil that drains poorly, a drain laid in a stone-filled trench collects the water and carries it farther away. It is a perforated pipe. National Asphalte also does French drains.

See French drains

Spot ground that was poorly prepared

A driveway laid on poorly prepared ground loses its shape over the winters. These signs often point to a problem under the surface:

low spots where water stays after the rain
cracks that keep coming back in the same place
a surface that heaves in winter
pavers that shift or sink

Redoing only the surface often brings the same problems back. You then have to fix the ground from underneath.

See the layers under a lasting driveway

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Common questions

Do I need to dig if I’m only redoing my asphalt?

Not always. If the old driveway has stayed flat and water drains off well, its crushed stone base can sometimes be reused. If it has dips or cracks that keep coming back, the problem is underneath. Redoing only the top then brings back the same problems. A contractor has to see the property to decide, and that is what the free estimate is for.

What happens to the soil that’s removed?

The truck hauls it off your property, along with the old asphalt or the old pavers. Under a driveway, nothing that rots or settles stays in the ground. Topsoil, for example, holds water and shifts as the ground freezes and thaws.

Do I need a drain under my driveway?

Not always. A good slope is often enough to move water away. A drain laid in a stone-filled trench helps where water stays, such as on flat land or in a driveway that sits lower than the street. This perforated pipe collects groundwater and carries it farther away. The estimate tells you whether your property needs one.

Do I need a permit to expand my driveway?

It depends on your city. Some cities regulate driveway width or the curb cut at the street. Before you expand it, check your municipality’s rules. Bring it up during the estimate too, so the driveway plan takes these rules into account from the start.

How do you prepare the ground under a driveway?