French drain replacement: the camera first, then the new drain
Learn more
A drain clogged with iron ochre or crushed gets replaced, in full or in part, once water jetting is no longer enough.
Solution ProFissure inspects your drain by camera and hands you a detailed quote, then replaces the failed section or the whole drain, membranes and backfill included.
Our French drain replacement services
French drain replacement targets an existing drain that has failed. Depending on the diagnosis, the job is a localized drain repair or a complete drain rebuild. For a house with no drain at all, our French drain installation service is the right starting point.
Partial replacement of one drain section
When the camera shows a single side crushed, sagging or invaded by roots, we replace that section only. The excavation is limited to one side of the house, and the invoice follows. The new run connects to the part of the existing drain that is still sound.
Full foundation drain replacement
When iron ochre or clogging affects the whole perimeter, replacing the entire foundation drain is the way forward. We replace the exterior drain, which captures water before it reaches the wall, rather than installing an interior drain under the slab. We pull out the old pipe, remove the clogged stone and the sediment, then lay a code-compliant system at the base of the foundation.
Drain replacement with foundation waterproofing
An open trench around the house is the best time to redo the waterproofing of the wall. Our foundation waterproofing service then joins the same job, with no second excavation.
Cleanouts and backwater valve
If your old drain had no cleanout, we add cleanouts during the work, so future maintenance can be done without digging. If the sump pit sits below street level, the Plumbing Code requires a backwater valve on its discharge pipe.
Signs your French drain needs replacing
A defective drain, or one that has reached the end of its service life, sends signals, in the basement and around the house:
- Water infiltration or dampness at the base of the walls, especially in spring
- Efflorescence and mould on the basement concrete
- Water standing against the foundation several days after rain
- A sump that stays dry while the ground is saturated, a sign of a clogged drain
- Orange deposits in the sump or at the outlet, a sign of iron ochre
- An original drain that goes back several decades: the age of the house matters
Iron ochre, a common cause in Quebec
Iron ochre forms when dissolved iron in groundwater meets oxygen and iron bacteria: the gelatinous deposit coats the pipe and clogs the stone, according to research from Polytechnique Montréal. High-pressure cleaning can remove it, but on an at-risk property it comes back. Once the clogging has reached the stone and the geotextile, only a new drain restores the flow.
Roots, crushed pipe and reverse slope
Tree roots enter through the perforations and form a fibrous plug. A poorly supported pipe gets crushed under the backfill. Clay soil that settles creates a reverse slope where water sits. Frost cycles and lateral soil pressure also shift the pipe. These defects call for a new drain, beyond what a simple cleaning can do.
Camera inspection before replacing a French drain
Before replacing a drain, we check its real condition. Our French drain camera inspection goes in through a cleanout and produces a video report: clogging, crushing, roots, slope. A cleaning costs $300 to $700 and a full replacement $12,000 to $20,000: the camera keeps you from paying for the second when the first is enough.
Our French drain replacement in 5 steps
The work takes five to seven days for a full replacement on a single-family home, depending on the perimeter, the access and the weather.
Utility locates and excavation (1 to 2 days)
A request to Info-Excavation comes before any excavation, as the RBQ requires. The mini-excavator opens the trench down to the base of the foundation, protecting whatever landscaping can be protected. When the water table is high, we pump the water out of the trench.
Removing the old drain (1 day)
We remove the old pipe, often perforated PVC or flexible agricultural drain, along with the clogged stone and the saturated geotextile. With the trench open, we also inspect the footing and the cracks in the wall.
Laying the new drain (1 day)
The new 4-inch rigid perforated drain, built to standard, is laid at footing level and covered on the sides and top with at least 6 inches of clear stone, itself covered with a geotextile membrane. The slope is set toward the outlet, with a cleanout for maintenance.
Membranes on the wall (1 day)
The wall receives an elastomeric membrane, then a Delta-MS dimpled drainage membrane that guides water down to the drain. Hydrostatic pressure against the foundation drops accordingly.
Connection and backfill (1 to 2 days)
The drain connects to the storm sewer, or to the sump pit and its sump pump. We backfill in lifts and correct the grade of the lot to direct surface water away. Grading and site restoration follow: lawn and window wells.
Does your French drain need replacing?
An on-site inspection, followed by a camera inspection if needed, tells you whether a cleaning is enough or whether you need a new drain.
French drain replacement cost
In Quebec in 2026, a French drain replacement is generally billed at $100 to $250 per linear foot, in Canadian dollars. The invoice most often lands between $12,000 and $20,000 for a standard single-family home, before taxes. It costs more than an installation in new construction, since the old drain has to come out and the digging happens around an occupied house. A partial replacement costs less, since the excavation is limited to one section. Our guide to French drain cost breaks down the related work.
Permits and aid for drain replacement
Rules vary from one city to the next. In Laval, French drain replacement is listed among the work exempt from a permit, while adding a drain requires one. We check your municipality’s by-law before the work begins.
Since October 1, 2026, the Adaptation component of the Rénoclimat program has offered assistance to adapt homes to flooding: simple work such as a backwater valve or a submersible pump with a battery. In recognized risk zones, heavier foundation protection work can also be funded. Check your eligibility before signing, because the program sets its own steps.
Why trust us with your French drain replacement
Replacing a drain means reopening the whole lot, so it is best done once, by a team that also knows foundations. Solution ProFissure, a family business in Sainte-Sophie holding RBQ licence 5770-6285-01, completed more than 350 projects in 2024. A 25-year transferable warranty covers our work. As a French drain and foundation contractor, we also handle foundation repair during the replacement when the wall needs it.
French drain replacement in the Laurentians
Our crews leave from Sainte-Sophie and cover the Laurentians, Laval, Lanaudière and Montreal’s North Shore, for single-family homes, semi-detached houses and row houses.
FAQ: French drain replacement
01When should a French drain be replaced?
When the pipe is crushed, sagging, invaded by roots or clogged to the point that cleaning no longer brings it back into service. A camera inspection confirms it. Water infiltration that returns every spring, a sump that stays dry and iron ochre deposits are the most common signs of a foundation drain at the end of its life.
02How much does French drain replacement cost?
Expect $100 to $250 per linear foot in Quebec in 2026, depending on complexity. A standard single-family home most often comes to $12,000 to $20,000 before taxes, and a partial replacement costs less. Bedrock, depth, obstacles and added waterproofing all move the price. Our free quote itemizes every line.
03Can you replace only part of a French drain?
Yes, when the camera shows that the problem is limited to one section: a crushed side, a run invaded by roots. The partial replacement connects to the existing drain. When iron ochre or age affects the whole perimeter, a full replacement saves you from reopening the lot two years later.
04Can a cleaning avoid a French drain replacement?
Sometimes. Unclogging with high-pressure cleaning removes iron ochre, sediment and silt from a drain that is still intact, for $300 to $700. A crushed pipe or a reverse slope, however, calls for a replacement. Our guide on how to clean a French drain explains what hydro-jetting can do.
05How long does a French drain replacement take?
Plan on five to seven days for a full replacement on a single-family home, from excavation to site restoration. A partial replacement takes less time. The weather, the presence of bedrock and access for the machinery can lengthen the job.
06Do you need a permit to replace a French drain?
It depends on the city. In Laval, French drain replacement is listed among the work that needs no permit, while adding a drain requires one. Other municipalities mainly regulate the point where the water is discharged. We check the municipal by-law before the work begins.
07Does Rénoclimat fund a French drain replacement?
The Adaptation component of Rénoclimat, in effect since October 1, 2026, helps adapt a home to flooding: a backwater valve or a submersible pump with a battery. In recognized risk zones, it also covers foundation protection work. The French drain is not named among the eligible work. Check your eligibility on quebec.ca before signing a contract.
08Does home insurance cover a clogged French drain?
Rarely. Home insurance covers sudden damage, such as a sewer backup if you carry the endorsement, not the wear of a drain or iron ochre. Water infiltration caused by a clogged drain generally remains the homeowner’s responsibility. Check your policy with your insurer.
A French drain that needs replacing?
Inspection, detailed quote, new drain and site restoration, all in the same job.