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In Quebec, exterior foundation waterproofing costs $90 to $150 per linear foot of treated wall, or $12,000 to $20,000 for a single-family home when the French drain is replaced in the same trench.
Why do two houses on the same street get quotes where one is double the other?
In this guide, you will find:
- The price per linear foot and the total cost for a single-family home, in Canadian dollars
- The five site factors that move the bill, from the footing to machinery access
- What the chosen membrane changes, from tar to the Delta-MS dimpled membrane
- Why an open trench is the only economical moment to replace the French drain
How much does foundation waterproofing cost?
The ranges below apply in Quebec in 2026, before taxes, for exterior work done by a licensed contractor. They hold for a wall that already lets moisture through, with efflorescence or mould in the basement, as well as for preventive waterproofing.
Price per linear foot of treated wall
Waterproofing is billed per linear foot of treated wall, meaning the length of foundation to dig out, and not by the square footage of the house. The rate runs from $90 to $150 per linear foot for complete exterior work: excavation down to the footing, cleaning the concrete, repairing cracks, applying the membrane and backfilling. When the French drain is replaced in the same trench, the range rises to $120 to $150 per linear foot. The process itself is explained in our article on how foundation waterproofing works.
Total cost for a single-family home
A Quebec bungalow or single-family home has a perimeter of 120 to 165 linear feet. On that basis, exterior waterproofing with a French drain replacement comes to $12,000 to $20,000 before taxes. The simplest jobs, on an open lot with a shallow footing, come in under $12,000. The heaviest ones, with iron ochre, bedrock or restricted access, go past $25,000. At Solution ProFissure, the quote breaks down every item: excavation, soil disposal, membrane, drain, backfill and finishing.
What the waterproofing quote includes and excludes
The price per linear foot covers excavation, hauling the excavated soil, cleaning the foundation wall, the membrane, backfill in compacted layers and rough grading. It excludes landscaping: new sod, interlocking pavers, asphalt, flower beds and a dismantled fence. Insist that every exclusion be put in writing. That is where the gap between a low quote and the final bill opens up.
Factors that drive foundation waterproofing cost
Five variables can be read on site before the first shovel hits the ground. The chosen membrane and the restoration of the yard complete the picture.
Linear feet of foundation to treat
Everything is billed by length. Treating all four sides of a 165-linear-foot house costs twice as much as treating the two walls that show signs of water infiltration. Partial treatment makes sense when water enters from one side only and the French drain along the rest of the perimeter is still working.
Excavation depth down to the footing
The wall is treated over its full buried height, down to the footing. In Quebec, the footing sits below the frost line, at 4 or 5 feet depending on the region, and deeper under a full-height basement. Every extra foot adds volume of soil to remove, store and put back. It also requires a wider trench for worker safety. An old rubble stone foundation is excavated in sections to avoid undermining the wall.
Machinery access to the property
An open lot is dug with a standard excavator, in a straight line, with the soil stored on site. A narrow urban lot, a mature hedge, an inground pool or a shed resting against the wall means working with a mini-excavator, trucking the soil out as the work progresses, sometimes digging by hand. The same 40-foot wall then moves from the bottom to the top of the range.
Soil type and excavated soil removal
Sandy soil digs quickly. The clay of the St. Lawrence Lowlands sticks to the bucket, holds water and compacts poorly, which stretches out the job. Bedrock calls for a hydraulic breaker, contaminated soil goes to an authorized site, and iron ochre bacteria require cleanouts so the drain can be cleaned in the future.
Concrete condition and cracks to inject
The membrane goes on a sound wall, which an inspection of the exposed concrete confirms. Active cracks, leaking cold joints and spalled concrete are repaired first. Injecting a crack costs $400 to $2,000 depending on its width and length. Our guide to foundation crack repair cost gives the breakdown by method. A wall too deteriorated to take a membrane shifts to a foundation replacement, which is a separate budget.
A fair price for your foundation
A free on-site assessment within 24 hours, with the linear footage measured and every item broken down.
Get my free assessmentWaterproofing cost by membrane type
The product applied to the wall determines the level of protection and explains a good part of the gap between $90 and $150 per linear foot. A damp-proofing coating repels moisture from the soil. A hydrophobic membrane resists hydrostatic pressure.
Tar and bituminous coating
Liquid tar remains the cheapest waterproofing product and keeps the job at the low end of the range. It hardens over the years, handles the micro-movements of concrete poorly and its useful protection rarely exceeds 10 to 15 years in our climate. It is the minimum treatment applied to new foundations just before backfilling.
Liquid rubber membrane
The liquid rubber membrane, an elastomeric product, goes on as a continuous coat and follows corners, cold joints and irregularities in the concrete. It stays flexible below freezing, which matters on a wall that goes through freeze-thaw cycles every winter. It puts the job in the middle of the range, with an advertised lifespan of more than 40 years, for a few dozen dollars more per linear foot.
Delta-MS dimpled membrane
The Delta-MS dimpled membrane is fastened over the liquid membrane and creates a draining air gap between the soil and the concrete. Water that passes through the backfill runs down the dimples to the French drain, which carries it away from the footing instead of letting it sit against the wall. This is the most expensive combination, at the top of the range. It is the one we favour for foundation waterproofing on clay lots that hold water.
Backfill and restoration after waterproofing excavation
Backfill in compacted layers and grading are priced separately, at $0.50 to $1 per square foot of disturbed ground. Finishing depends on what was there before the work: sod, flower beds, interlocking pavers or asphalt are redone at the landscaper's price and are almost always left out of the waterproofing quote. Mature landscaping can add several thousand dollars to the budget.
Since the trench is already open down to the footing, this is the only time the French drain cost is limited to its marginal cost: only the perforated pipe, the crushed stone and the filter fabric are added, because the same excavation, the same labour and the same site restoration serve both jobs. The combined rate therefore starts at $120 per linear foot instead of doubling.
Interior vs exterior basement waterproofing cost
Exterior treatment protects the concrete itself, because the barrier goes on the side where the water comes from. It costs $90 to $150 per linear foot and requires excavation, which means machinery, soil removal and restoring the yard.
Interior treatment manages water once it is inside. The perimeter of the slab is broken out and an interior drain, a drainage membrane and a sump pump connected to a sump pit are installed, for a total of $15,000 to $25,000. It is the answer when a shared wall, an inground pool or a lane makes excavation impossible. It is also the first step when water is already coming through a basement wall.
How Quebec's climate affects waterproofing cost
Freeze-thaw explains why waterproofing costs more here than elsewhere. The footing has to be uncovered below the frost line, at 4 or 5 feet depending on the region, which sets a minimum excavation depth and therefore a minimum price. In spring, snowmelt saturates an already heavy clay soil, the water table rises against the wall and the membrane faces its yearly test.
The season also shows up on the bill. The work is done on thawed ground, from mid-May to the end of October. Schedules fill up as soon as the first spring leaks appear. The Quebec Construction Code governs this work: article 9.14.2.1 requires drainage around the footing by a drain or a layer of crushed stone.
Comparing foundation waterproofing quotes
Three quotes in the same format are the only way to judge a price per linear foot. Ask for the exact length of wall treated, the planned excavation depth, the membrane named by product, what happens to the excavated soil, the backfill details and the share of landscaping left to you. Our guide on how to choose a foundation contractor covers the licence and warranty checks to make before signing.
At Solution ProFissure, the on-site assessment is free and done within 24 hours, RBQ licence 5770-6285-01 is active and crack repairs are covered by a transferable 25-year warranty that stays with the house when it is sold. Our installations meet RBQ and APCHQ standards. More than 1,300 customers and 350 projects completed in 2024 have gone through this checklist, from our head office in Sainte-Sophie, in the Laurentians, to Laval and Lanaudière. If the foundation wall itself is the problem, see our foundation repair and replacement service.
Your no-obligation waterproofing quote
Send us photos and your basement dimensions, and you will receive a range broken down item by item.
Request my quoteFAQ: foundation waterproofing cost
How much does foundation waterproofing cost in Quebec?
Expect $90 to $150 per linear foot of treated wall for exterior work, then $120 to $150 per linear foot when the French drain is replaced at the same time. For a single-family home with a perimeter of 120 to 165 linear feet, the bill falls between $12,000 and $20,000 before taxes. It climbs past $25,000 on a complex job, with iron ochre or restricted access.
Does the price include excavation and backfill?
Yes, in the vast majority of quotes. The price per linear foot covers excavation down to the footing, hauling the soil, cleaning the wall, the membrane, backfill in compacted layers and rough grading. Landscaping, such as sod, interlocking pavers or flower beds, is billed separately, at around $0.50 to $1 per square foot just to level the ground again.
Is it cheaper to waterproof a basement from inside?
Rarely, once you see the full picture. An interior system, with slab breaking, an interior drain, a drainage membrane and a sump pump, costs $15,000 to $25,000. It manages water that has entered the basement instead of protecting the concrete. It also leaves the wall exposed to freeze-thaw. It is mainly chosen when the lot makes excavation impossible.
Should you replace the French drain at the same time?
It is almost always the right call when the drain is more than 25 years old. The trench is already open down to the footing, the machinery is on site and restoring the yard is already in the budget. The combined rate starts at $120 per linear foot instead of $90, a gap far smaller than the cost of a second excavation five years later.
How much does crack injection cost before the membrane?
From $400 to $2,000 per crack, depending on its width, length and accessibility. Expanding polyurethane injection is done before the membrane goes on, because a membrane applied over an active crack eventually tears at the same spot. At Solution ProFissure, these crack repairs are covered by a transferable 25-year warranty.
Which membrane offers the best value for money?
In most cases, the elastomeric liquid rubber membrane. It costs a few dozen dollars more per linear foot than tar, stays flexible in cold weather and has an advertised lifespan of more than 40 years. On clay soil that holds water, a Delta-MS dimpled membrane is added on top to create a draining air gap.
Are landscaping and the lawn included in the price?
No, unless stated in writing. Excavating around the house destroys the sod, part of the flower beds and sometimes a section of interlocking pavers or asphalt. The waterproofing quote usually stops at compacted backfill and grading. Have the landscaping priced separately and include it in the overall budget from the start.
Which season is cheapest for foundation waterproofing work?
The work is done on thawed ground, from mid-May to the end of October. Spring concentrates demand, since leaks show up during snowmelt, which keeps prices firm. Late summer and early fall often offer more availability, drier soil and better membrane adhesion on the concrete.
What will your waterproofing cost?
A foundation contractor measures your walls, checks your drain and prices everything for free.
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