When Do You Need Excavation to Replace a French Drain in Longueuil?

Foundation repair, French drain, excavation

Marco comes to you in person for every estimate. Reachable 7 days a week, 8 a.m. to 5 p.m.

Get your free estimate

When Do You Need Excavation to Replace a French Drain in Longueuil?

Foundation repair, French drain, excavation

Marco comes to you in person for every estimate. Reachable 7 days a week, 8 a.m. to 5 p.m.

Get your free estimate

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Get your free estimate

In a city where nearly one dwelling in three dates from the 1970s, the original drain has had its day

Longueuil has three boroughs: Vieux-Longueuil (141,794 residents in the 2021 census), Saint-Hubert (87,647) and Greenfield Park (16,965). According to Wikipedia, 32% of the city’s dwellings were built during the 1970s, the decade when the most building took place. A drain laid back then is about 50 years old today, while CAA-Québec gives about 40 years as a drain’s normal lifespan. Whether you live near Taschereau Boulevard, in Vieux-Saint-Hubert or in Greenfield Park, the first question is the same: has your home’s drain ever been redone?
In April 2023, following the floods of September 13, 2022, the City of Longueuil held a public information meeting in Vieux-Longueuil on its drainage network (in French). It reminded residents that, on the private side, water can get in several ways: gutters connected to the foundation drain, cracks in the foundation wall, cracks or joints in the slab, surface runoff, backflow through a missing or faulty valve, or overflow of a retention pit whose pump is inadequate. A new drain fixes only one of those paths, which is why a full diagnosis comes before the excavator. To judge a crack, read When Is a Foundation Crack Serious in Quebec?
In Longueuil, Marco Réparation de Fondation repairs foundation cracks (polyurethane or epoxy injection), cleans, repairs or replaces French drains, installs interior drains and waterproofing membranes, and excavates around the foundation when the condition of the wall calls for it. Marco does every estimate and every job site inspection himself (RBQ license No. 5775-3246-01). To choose between an exterior and an interior drain, read Interior or Exterior French Drain: Which Should You Choose?

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What the City of Longueuil requires for a French drain

These requirements come from the City’s “Travaux de plomberie” technical sheet from the planning and urban development department (2025, in French) and from a public presentation by the City on bylaw CO-2021-1141 (April 5, 2023, in French). They do not replace the official bylaw: confirm your case with the City (311) before starting.

  • Inspection before backfill. After the permit is issued, you must contact the City inspector to arrange inspections. No exterior backfill or interior slab pour is allowed before the inspector’s visit, and the City must be notified at least 24 hours before backfilling.
  • The drain. At least 100 mm (4 in.) in diameter, perforated, covered with a geotextile membrane, with at least 150 mm (6 in.) of crushed stone or clean granular material on the sides and top.
  • Retention pit and pump. The French drain must discharge into a retention pit, connected by gravity to the private storm sewer connection (with exceptions) and fitted with a cleanout, a trap and a backwater valve. A pump of sufficient capacity and in good condition is required in every pit (articles 86 to 88).
  • Pump discharge. Pumped water must be discharged onto a permeable surface, at least one metre from the building.
  • Backwater valves. They are required on connections that receive stormwater from exterior surfaces lower than the neighbouring ground (garage ramps, exterior entrances, French drains) and on basement wastewater connections (articles 101 and 102). The City asks owners to have them inspected every year.
  • Gutters. Water must be directed onto the lot, away from the foundations.

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Crack repair service

The Process

Interior
Marco - Réparation de fondation

Crack repair

Polyurethane injection

We will determine the cause of the cracks

Epoxy injection

Increases the strength of the structure and the concrete

French drain

We will clean, repair or replace your drains if they are no longer working

Exterior
Marco - Réparation de fondation

Crack repair

Membrane installation

3 water-repellent membranes are applied to the foundation wall

Excavation

We dig with high-performance equipment to minimize damage

Say goodbye to leaks

Keeps water from reaching the foundation by draining it to the base of the wall

Questions about drainage and excavation in Longueuil

Do I need a permit to replace a French drain in Longueuil?

The City’s technical sheet provides for a permit for this work: once it is issued, you must contact the inspector to arrange inspections, and no exterior backfill or interior slab pour is allowed before the inspector’s visit. The City must also be notified at least 24 hours before backfilling. Confirm the details of your file with the City at 311.

Does my French drain have to discharge into a retention pit with a pump in Longueuil?

Yes, under bylaw CO-2021-1141 (articles 86 to 88) as presented by the City: the French drain discharges into a retention pit, connected by gravity to the private storm sewer connection except where exceptions apply, with a cleanout, a trap and a backwater valve, and a pump of sufficient capacity and in good condition must be installed in every pit.

Where must my sump pump water be discharged in Longueuil?

According to the City’s presentation, pumped water must be discharged onto a permeable surface, at least one metre from the building. Gutters must also direct water onto the lot, away from the foundations.

Which backwater valves are required on my property in Longueuil?

The bylaw requires a backwater valve on connections that receive stormwater from exterior surfaces lower than the neighbouring ground, such as garage ramps, exterior entrances and French drains, and on wastewater connections for basement fixtures and floor drains (articles 101 and 102). The City asks owners to have them inspected and checked every year.

My Longueuil French drain is over 40 years old: does it have to be replaced?

Not automatically. CAA-Québec gives about 40 years as a drain’s normal lifespan, then describes three levels of work: hydro-jet unclogging, repair of an obstructed section or full replacement, with a camera diagnosis before deciding. When excavating outside is difficult or impossible, an interior drain with a pump can be considered.

Who comes to assess my drain in Longueuil, and how do I book the visit?

Marco himself comes on site for the free estimate. Book by filling out the form on this page or by calling (438) 763-0737 between 8 a.m. and 5 p.m., every day. His company holds RBQ license No. 5775-3246-01 from the Régie du bâtiment du Québec.

Longueuil and the South Shore: where we work

Marco serves Longueuil, Brossard and Saint-Lambert on the South Shore, as well as Montréal, Laval, the West Island and Salaberry-de-Valleyfield. We come to you. See also our Brossard excavation and South Shore excavation pages.
A question before booking a visit? Call (438) 763-0737, every day from 8 a.m. to 5 p.m., or check our Google listing.

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