French Drain — cleaning, unclogging & replacement
Basement water infiltration, persistent humidity, clogged drain? Our technicians inspect, clean, or replace your French drain with the equipment suited to every situation.
The role of the french drains
The French drain is an underground drainage system installed around the perimeter of the foundations. Its role: evacuate groundwater when the water table rises and exerts hydrostatic pressure on the footings and slab.
It acts as a safety valve: accumulated water chooses the easiest path — the drain — rather than seeping through cracks or the slab/wall joint.
Without a drain in good condition, all this pressure shifts onto your foundation walls: risk of infiltration, mold, and eventually, costly structural damage.
Rain & Water Table
Water accumulates around the foundations and rises in the saturated soil.
Drain Capture
The perforated pipe, wrapped in geotextile, captures water before the foundation.
Gravity Discharge
Water is directed toward a sump pump or storm sewer.
Protected Foundations
Pressure is dissipated — your basement stays dry.
Lifespan & degradation factors
A French drain lasts about 25 to 30 years — but several factors can shorten this lifespan and require intervention much sooner.
Clogging by Sediments
When the slope directs surface water toward the foundations, fine particles gradually clog the drain's geotextile membrane.
Iron Ochre
In Quebec's clay soils, bacteria produce an orange sludge that clogs the drain in just a few years.
Root Intrusion
Roots seek moisture and infiltrate cracks in the pipes, causing blockages and breakage.
Sagging or Damage
Aging materials (PVC, clay tile) and ground movement create water retention points.
Signs of a failing drain
These signals warrant a prompt inspection — the longer you wait, the worse the foundation damage becomes.
Infiltration During Heavy Rains
Water in the basement during or after rain means the drain is no longer performing its evacuation role.
Mold on Foundations
Dark spots, efflorescence, or mold on the concrete indicate excessive, poorly drained humidity.
Backing-up floor drain
When the floor drain backs up during heavy rains, the French drain is often saturated or clogged.
Persistent Floor Humidity
A basement floor that is always humid, even in dry weather, indicates poorly drained pressure beneath the slab.
Home Aged 25–30+
Without drain maintenance and after 25 years or more, a preventive inspection is strongly recommended.
Orange sludge (ochre)
Orange-rust traces in the floor drain or sump pit signal iron ochre.
Cleaning or replacement?
The answer depends on the actual condition of your drain. Only a camera inspection can confirm with certainty — here are the general criteria:
CLEANING / UNCLOGGING
A powerful high-pressure water jet (hydrojetting) dislodges blockages and cleans the inner pipe walls.
- Pipe intact but clogged
- Accumulation of sediment or iron ochre
- Geotextile partially clogged
- Drain less than 25 years old in good condition
- Solution without major excavation
COMPLETE REPLACEMENT
Excavation around the foundation perimeter, removal of the old system, and installation of a new drain with geotextile and filtering gravel.
- Pipe collapsed, cracked, or broken
- Clay tile drain (installed before 1980)
- Complete blockage by roots
- Drain over 30 years old at the end of its lifespan
- Infiltrations despite cleanings
Three levels of intervention
From preventive cleaning to full replacement with excavation — a tailored level for your drain's condition.
Our work process
Each intervention follows a structured process to make the right diagnosis and guarantee a lasting result.
Call & Evaluation
You describe the situation. We assess the urgency and schedule as quickly as possible.
Camera inspection
The color camera identifies the exact location and nature of the issue: clogging, sagging, damage, or iron ochre.
Hydrojetting ou excavation
Based on the diagnosis: cleaning using high-pressure jetting or excavation and system replacement.
Verification & Report
We check the flow and provide a full report — useful for an insurance claim.
Preventive drain maintenance
- 1
Clean Every 3 to 5 Years
Periodic cleaning via hydrojetting prevents sediment buildup that eventually clogs the drain.
- 2
Correct the Ground Slope
Ground sloped toward the house overloads the drain. Regrading the soil extends system life.
- 3
Maintain the Sump Pump
A faulty pump nullifies the drain's effect; check it every fall before the melt.
- 4
Keep Tree Roots Away
Avoid fast-growing trees near foundations; inspect every 2–3 years if present.
- 5
Monitor Gutters & Downspouts
Direct rainwater at least 2 meters away from foundations to avoid overloading the drain.
Throughout Montreal, Laval & the Laurentians
Locally based, Drain MPR serves the following municipalities promptly for any French drain service.
FAQ — French Drain
How do I know if my French drain is clogged or defective?
Is it better to clean or replace my French drain?
What is the lifespan of a French drain?
Does replacement require excavation?
What is iron ochre and how does it affect my drain?
Does my home insurance cover damage from a failing drain?
Additional services
Working on a French drain can sometimes uncover related issues. Here are our services for a comprehensive solution.
Are you worried about your French drain?
Our technicians will assess, clean, or replace your drain. Free quote, fast service.
