French drain (weeping tile): signs and replacement

A French drain, also called weeping tile or a foundation drain, is the perforated pipe laid at the foot of the foundation walls. It collects water from the soil and carries it away from the house, to a sump or to the storm sewer depending on the house. Over the years it can clog, sag or silt up, and water then builds up against the basement walls.

1. Signs the drain is no longer doing its job

• Water seeping in or damp stains at the bottom of basement walls, especially in spring or after heavy rain.
• Orange deposits (iron ochre) in the sump pit, the backwater valve or the cleanout.
• A sump pump that starts very often, or a sump that stays dry even in the rain.
• White efflorescence on the concrete, a musty smell, a carpet or lower wall that stays damp.

2. Camera inspection first

A camera run through the drain shows its real condition: blocked, crushed, clogged with ochre or just dirty. Sometimes pressure cleaning is enough. Replacement means digging around the house: it is a big job, only worth doing if the inspection justifies it. Ask for a copy of the video and the report. Check the gutters and the slope of the yard before deciding: a lot of seepage comes from surface water rather than from the drain.

3. French drains and gutters: the rules in Repentigny, Brossard, Pointe-Claire and Chambly

On its sewer and water page (in French), the City of Repentigny says gutters must never be connected to the foundation drain or to the municipal sewer: an extension should carry rainwater to the lawn or flower beds, 1.5 m or more from the foundation. It also advises a yard that slopes very slightly toward the street, window wells in front of ground-level windows and a backwater valve on the sump pit drain. For permits, the City (in French) asks only for an online declaration of work to replace an existing French drain, but a permit to install a new one.

Elsewhere, the rules vary from town to town. In Brossard, basement finishing and French drains have their own procedure, online through the Bciti portal (Travaux majeurs et transformations, in French). In Pointe-Claire, the City (in French) requires a building permit for French drains, while other work on private service lines needs a certificate of authorization. In Chambly, the “Branchement Réfection” permit type covers sewer and water service lines and includes the French drain (City of Chambly permits, in French). Before signing, ask who will apply: the contractor or you.

4. What a replacement quote should state

• Which sides of the house, the length of drain and how deep the excavation goes.
• The type of drain, the filter membrane and the clear stone around the pipe, and how it connects to the sump or the sewer.
• Waterproofing of the walls and crack repair while the foundation is exposed.
• Cleanouts, the backwater valve and the pump if there is a sump pit.
• Restoring the lawn, driveways, flower beds and window wells.
• Who gets the permit, the warranty offered and a camera inspection after the work.

5. The licence and next steps

This work involves excavation, the foundation and often plumbing: the company must hold an RBQ licence whose subcategories cover each part. Ask which ones and check the licence. To find companies near you, see contractors in Repentigny, in Brossard or in Pointe-Claire, or describe your drain problem to get quotes. See also: foundation cracks and renovating a basement.