French Drain Installation

A French drain is a gravel-filled trench containing a perforated pipe that collects groundwater and directs it away from your foundation by gravity. The system works passively — there are no moving parts, no electricity required, and nothing to maintain beyond periodic inspection. Water enters the perforated pipe through hundreds of small holes, travels along the pipe's slope, and exits at a sump pit, storm drain connection, or daylight discharge point.

In Laval, French drains are not just a waterproofing upgrade — for many homes, they are a necessity. The island's clay soils have naturally poor drainage; water doesn't percolate downward quickly and instead moves laterally toward the path of least resistance — your foundation wall. Neighborhoods in Chomedey near the Rivière des Prairies, low-lying sections of Duvernay, and areas in Laval-des-Rapides and Pont-Viau built near former marsh areas have some of the highest groundwater tables in the region. Without a drainage system at the footing level, these homes are in a permanent state of hydrostatic pressure.

Beyond new installations, we also replace failed original perimeter drains — the clay tile or thin plastic drain systems installed in homes built between the 1950s and 1980s. These old systems are commonly found collapsed, root-clogged, or silted shut under homes in Auteuil, Saint-Vincent-de-Paul, and Vimont. A camera inspection of your existing drain can confirm whether replacement is warranted.

Interior French drain installation involves cutting a narrow channel (typically 12–16 inches wide) around the perimeter of the basement floor, excavating to the footing level, installing perforated pipe wrapped in filter fabric within a gravel bed, and then patching the concrete. The collected water is directed to a sump pit where a pump discharges it outside the home.

The primary advantage of interior installation is that it requires no exterior excavation — no disruption to landscaping, fencing, decks, or neighboring properties. It is also unaffected by exterior conditions and can be installed year-round. Interior systems are typically completed in 1–3 days and are significantly more cost-effective than full exterior excavation.

Modern interior drainage systems use dimple-mat drainage channels that capture water seeping through the wall face above the footing — something traditional footing-level pipe alone cannot address. This makes them highly effective at managing the diverse moisture entry patterns typical of older Laval homes in Sainte-Rose, Fabreville, and Sainte-Dorothée.

All interior systems are installed with a sump pump. We recommend battery-backed pumps for homes in high water table areas like Chomedey and low-lying sections of Duvernay.

Exterior French drain installation is the most thorough drainage solution for a Laval home. The process involves excavating the foundation perimeter down to the footing, cleaning and re-waterproofing the exposed wall, installing a perforated drainage pipe at the footing base within a granular drainage layer, and then carefully backfilling with clear stone and filter fabric to prevent silting.

Exterior drains intercept groundwater before it ever contacts the foundation wall, reducing hydrostatic pressure to near zero. Combined with a fresh exterior waterproofing membrane, this approach provides the most durable long-term protection. Homes in Saint-François, Laval-Ouest, and Saint-Vincent-de-Paul that have never had drainage systems installed are excellent candidates for full exterior work during landscape renovation or pool installation projects when excavation costs can be partially shared.

Our French drain installation teams serve all areas of Laval including Chomedey, Vimont, Duvernay, Fabreville, Sainte-Rose, Auteuil, Pont-Viau, Laval-des-Rapides, Sainte-Dorothée, Saint-François, Saint-Vincent-de-Paul, and Laval-Ouest. We carry full liability insurance and RBQ certification. Free site assessments are available for all drainage inquiries.