Your foundation carries your entire home. When water works its way through, the damage goes far beyond a damp basement — it threatens the structure itself. We protect foundations permanently, using proven systems and materials that hold up in Ontario's climate.
Every wall, floor, and roof in your home rests on the foundation. When water penetrates it — through cracks, through the wall face, through the floor joint — it doesn't just create a wet basement. It begins a slow process of deterioration that compromises the structure holding your home together.
Foundation waterproofing isn't just about keeping a basement dry. It's about protecting the structural integrity of the most important component of your property. Water causes concrete to spall and degrade. It corrodes reinforcing steel. It expands through freeze-thaw cycling, widening foundation cracks with every winter. And once moisture gets into the wall assembly, mould, rot, and air quality problems follow.
Most homes in this region were built with dampproofing — a tar-based coating that resists moisture vapour but cannot withstand liquid water under pressure. As these coatings age, crack, and separate from the wall, the foundation is left essentially unprotected. True exterior waterproofing, using a membrane designed to hold against hydrostatic pressure, is a fundamentally different level of protection — and it's what every foundation in this climate ultimately needs.
At AW Waterproofing Solutions, we've waterproofed foundations across Napanee, Belleville, Kingston, and surrounding communities for years. We understand the soil conditions, the water table behaviour, and the freeze-thaw pressures that foundations in this region face. When we assess a foundation, we look at the full picture — not just where the water is entering, but why, and what it will take to stop it permanently.
Foundation water problems don't always announce themselves dramatically. Many of the most serious issues develop quietly behind finished walls or beneath the floor slab. These are the signs we look for — and what each one tells us about what's happening in the foundation.
Vertical shrinkage cracks, diagonal settlement cracks, and horizontal cracks caused by lateral soil pressure are all entry points for water. Any crack in contact with saturated soil is a potential leak — and cracks only widen with time and freeze-thaw cycling.
Dark staining, tide marks showing previous water levels, and mineral deposits on the wall face all indicate that water has been moving through or along the foundation surface — whether or not the wall appears dry right now.
White, chalky deposits on concrete or block walls are caused by water dissolving minerals and depositing them on the surface as it evaporates. They're a reliable indicator of water movement through the foundation, even if the wall feels dry.
Concrete that is flaking, pitting, or crumbling on the surface — a condition called spalling — is often caused by freeze-thaw cycling combined with moisture in the concrete. It's a sign the foundation material itself is being degraded by water.
A foundation wall that is visibly bowing inward indicates serious lateral soil pressure — the same pressure that drives water through the wall. This is a structural warning sign that requires immediate professional assessment, not just waterproofing.
Walls or floors that feel damp or cold to the touch even without visible water — or a basement that never fully dries out — indicate that moisture is continuously migrating through the foundation material. Often dismissed as "normal," it never is.
Mould growing directly on concrete or block foundation walls requires sustained moisture to establish. If it keeps returning after cleaning, the moisture source — water moving through the wall — hasn't been addressed.
Floors that slope, doors that stick, or visible gaps between walls and floors can indicate foundation settlement driven by soil erosion from water intrusion. Long-term water infiltration removes the soil stability the foundation relies on.
Understanding why a foundation loses its ability to resist water is the first step to fixing the problem correctly. The same external symptom — a wet basement — can have several different root causes, each requiring a different approach.
Most homes built before the 1990s received a tar-based dampproofing coat during construction. This coating was never designed to withstand hydrostatic pressure — only moisture vapour. As it ages, it becomes brittle, cracks, and separates from the wall. The foundation is then essentially unprotected against water under pressure.
When soil surrounding a foundation becomes saturated — after heavy rain or spring snowmelt — water pressure builds against the outside of the wall. This hydrostatic pressure can push water through concrete, mortar joints, and cracks that would otherwise hold under normal dry conditions. It is the primary driver of foundation water intrusion in this region.
All foundations move to some degree over decades of seasonal temperature changes, soil moisture variation, and structural loading. This movement creates cracks — particularly at corners, window openings, and areas of concentrated stress. Each crack is an open path for water under hydrostatic pressure.
A working drainage system — weeping tile, drainage board, proper grading — manages water around the foundation so it never builds to a pressure that the wall must resist. When these systems fail or were never properly installed, the full force of saturated soil presses directly against the foundation wall and its aging coating.
Heavy clay soils — common in parts of Eastern Ontario — absorb and hold water exceptionally well, creating prolonged periods of high soil moisture against the foundation after rain events. Clay also swells as it absorbs moisture, increasing lateral pressure on foundation walls. Homes built in clay-heavy areas need a waterproofing system rated for sustained pressure, not just occasional moisture.
Water that enters a crack or the surface of concrete expands when it freezes — by about 9% in volume. Over repeated freeze-thaw cycles through Canadian winters, this expansion progressively widens cracks, spalls concrete surfaces, and weakens mortar joints. A foundation that has been wet through multiple winters accumulates more damage every season.
Drainage board — the dimpled protection layer applied over an exterior waterproof membrane — serves two purposes: protecting the membrane from backfill damage and creating an air gap that directs water downward to the weeping tile rather than into the membrane. When drainage board is missing or damaged, water presses directly against the membrane under the full weight of saturated soil.
When a foundation is excavated and then backfilled, the disturbed soil around the foundation is far more permeable than undisturbed soil — it drains more water toward the foundation rather than away from it. Without proper drainage board, weeping tile, and grading, the backfill zone becomes a water collection area that funnels every rainfall directly to the foundation wall.
We tailor every solution to the specific foundation type, water intrusion pattern, soil conditions, and budget of each home. We don't sell packages — we diagnose what's happening and recommend what it actually takes to fix it.
The most comprehensive and durable approach to foundation waterproofing. We excavate around the full perimeter — or the affected sections — of the foundation to expose the wall from footing to grade. The existing surface is cleaned and prepared, and a Duraflex rubberized membrane is applied directly to the concrete or block, creating a seamless, fully bonded waterproof barrier.
Over the membrane, we install a drainage board that protects the membrane from backfill pressure and creates a drainage plane that directs water downward to the weeping tile system at the base of the footing. New or refreshed weeping tile — perforated pipe in a crushed stone bed — carries that water away from the foundation and to daylight or a sump.
Backfill is then placed and compacted in staged lifts to minimize future settlement. Done correctly, exterior waterproofing stops water before it ever contacts the foundation wall — the most permanent form of protection available.
Duraflex Membrane Drainage Board Weeping Tile Full ExcavationFor water entering through a specific crack in a poured concrete foundation, polyurethane or epoxy injection is often the most direct and cost-effective solution. We install injection ports along the crack and inject material under controlled pressure, filling the crack from its face to its full depth.
Polyurethane foam expands as it cures, filling irregular voids and creating a flexible waterproof seal that can accommodate minor foundation movement without re-cracking. Epoxy injection creates a rigid, structural bond — restoring the tensile strength of the concrete across the crack in addition to sealing it against water.
Crack injection works best on active or dormant cracks in poured concrete walls. It is not the right solution for block foundations, for cracks showing structural movement, or for water entering through the wall face rather than through a discrete crack.
Polyurethane Injection Epoxy Injection Same-Day RepairWhen exterior waterproofing isn't practical or when water is entering through the floor or floor-wall joint rather than the wall face, an interior drainage system provides highly effective water management. We install a drainage channel along the perimeter of the basement floor at the base of the foundation walls, beneath the slab level, that intercepts water as it enters and directs it to a sump pit and pump.
Interior drainage doesn't stop water from entering the foundation — it manages it before it can cause damage. For many homeowners, particularly those in older homes or with limited exterior access, it is the most practical permanent solution.
Drainage Channel Sump Pump Permanent SystemWhen the foundation's perimeter drainage system has failed — collapsed pipe, root infiltration, or decades of silt accumulation — replacing it restores the drainage function that keeps groundwater pressure off the foundation wall. We install new perforated pipe in a proper crushed stone bed around the base of the footing, restoring the original design intent of the drainage system.
Weeping tile replacement is frequently combined with exterior membrane work when we're already excavating — the two systems together form a complete, redundant foundation protection strategy.
Perforated Pipe Crushed Stone Full PerimeterA properly sized and maintained sump pump system is the final line of defence in any foundation water management strategy. We install primary pumps sized to the actual water volume your foundation produces, paired with battery backup systems that ensure continued operation during power outages — which frequently coincide with the most severe rain events.
If your existing pump is cycling constantly, struggling to keep up, or has failed entirely, we assess the full drainage system rather than simply replacing the pump in isolation. A pump that runs constantly is usually a sign of a drainage problem that the pump is compensating for.
Primary Pump Battery Backup Properly SizedFoundation waterproofing is one of the most consequential decisions a homeowner makes — and one of the least visible after it's done. You're buying something you'll never see again once it's backfilled. That makes the integrity of the contractor and the quality of the materials everything.
We don't recommend a solution before we understand the problem. A free on-site assessment gives us the full picture — foundation type, water source, drainage conditions, and the extent of any existing damage. The right solution follows from an accurate diagnosis.
Every project is backed in writing. If the system fails due to our workmanship, we return and fix it at no cost. We're confident in our materials and methods — and we want our customers to be too, with documentation that makes that promise binding.
We apply Duraflex rubberized membrane — not the tar-based coatings that were standard decades ago and are still used by some contractors today. The difference in long-term performance is significant. Duraflex stays flexible and bonded through decades of freeze-thaw cycling. Tar does not.
If a crack injection solves your problem, that's what we'll recommend — not full excavation. We explain what we're seeing, what the options are, and what we'd genuinely do if it were our foundation. No upselling. No fear tactics. Just straight information.
The quality of a waterproofing system lives and dies in the installation. Membrane application, drainage board placement, weeping tile sizing, and backfill technique all matter enormously. Our crew is trained on these details — not simply handed a bucket and a brush.
We pick up the phone after the job. If a customer has a concern, we respond. If something isn't right, we come back. Our business in this area depends on our reputation — and we take that seriously on every single project we complete.
The quality of any waterproofing system is determined by the membrane that forms its core. We have chosen Duraflex because it outperforms alternatives in every condition a Canadian foundation actually faces — and because we've seen what happens to foundations protected by inferior products after fifteen or twenty years.
Duraflex is a polymer-modified rubberized membrane applied directly to the foundation surface. It bonds to the concrete or block and remains permanently flexible — it doesn't crack through freeze-thaw cycling, it doesn't peel or delaminate under hydrostatic pressure, and it doesn't require seams that can open over time. It is a true liquid-applied waterproof membrane, not a dampproofing coat.
We are certified Duraflex installers. That certification isn't a marketing credential — it means we have been trained in surface preparation, penetration detailing, drainage integration, and the application standards that determine whether the membrane performs as designed. An improperly applied membrane fails regardless of the product's quality. Proper installation is what the certification reflects.
Professional-grade rubberized waterproofing membrane. The standard for certified foundation waterproofing across Canada.
AW Waterproofing Solutions holds Duraflex installer certification. When you see our crew working on your foundation, you're getting trained applicators who understand the full system — not just the membrane, but the drainage components, protection layers, and installation techniques that make the system function as designed for decades.
Working on foundations in this region for years produces observations that don't come from product literature or training manuals. These are the patterns we've seen consistently — the things that only become obvious after diagnosing and repairing hundreds of foundations.
The single most common mistake we see in foundation waterproofing — by both homeowners and contractors — is treating the symptom rather than the system. A crack is sealed, but the drainage board that was allowing water to press against the wall is never replaced. A membrane is applied to a wall that still has failed weeping tile at the base. The symptom disappears temporarily, but the underlying pressure conditions that caused it remain unchanged. Six months later, the water finds a new path in.
Horizontal cracks in block foundation walls are the most serious thing we encounter on a regular basis. They indicate that the lateral soil pressure against the wall has exceeded the structural capacity of the block and mortar assembly. The wall is not just leaking — it is failing. We've seen horizontal cracks that were cosmetically patched and left for years while the wall slowly bowed further inward. By the time the homeowner called us, what could have been a waterproofing project had become a wall repair and rebuild. Early assessment is everything with horizontal cracks.
When we open up a foundation during exterior waterproofing, we frequently find that what was applied at construction bears very little resemblance to what a homeowner was told was there. "Waterproofed at construction" often means a thin coat of tar-based dampproofing applied to a wall that had already begun to cure — with poor adhesion and no drainage board. In some cases, particularly on older homes, we find nothing at all on the exterior wall face. The assumption that a newer home has adequate waterproofing is often wrong.
Spring is when foundations that were marginal all year finally fail. The combination of frozen ground that can't absorb snowmelt, a water table raised by winter accumulation, and the rapid temperature swings of late March and April create the most demanding conditions a foundation faces. We take more calls in the six weeks after spring thaw than at any other time of year — and the majority of those calls are from homeowners who knew there was a minor water issue but assumed it was manageable. Spring proved otherwise.
The quality of the backfill operation matters enormously to the long-term performance of an exterior waterproofing system. We've inspected failed exterior jobs where the contractor did everything right with the membrane and drainage board, but then backfilled too aggressively — using heavy equipment that pushed the drainage board sideways and created gaps in the membrane. Proper backfill is staged, compacted in controlled lifts, and keeps equipment at a safe distance from the wall. It's the last step and it's easy to rush. We don't.
Foundation type matters more than most homeowners realize when choosing a waterproofing approach. Poured concrete foundations and block foundations behave very differently under water pressure. A poured wall that cracks develops discrete, injectable cracks. A block wall that gets wet allows water to travel through the hollow cores of the blocks themselves — so sealing every visible crack and mortar joint still leaves the wall face permeable. Block foundations almost always benefit from exterior membrane work or interior drainage rather than crack injection alone.
Drainage board is one of the most underspecified components in exterior foundation waterproofing — and one of the most important. Its job is to create a gap between the backfill soil and the waterproof membrane so that water can drain freely downward to the weeping tile rather than building up as pressure against the wall. When drainage board is omitted, undersized, or installed backward, the membrane faces the full weight of saturated soil with no drainage relief. We see this on competitor work regularly. We never skip it.
We are occasionally asked why foundation waterproofing costs what it does. The answer is the same every time: you're paying for excavation of several feet of soil around a structure that cannot be disturbed carelessly, for a certified membrane that requires trained application, for drainage components that need to be properly sized and installed, and for backfill that needs to be staged correctly to protect everything that was just put in place. The cost reflects what the work actually requires — and the consequence of shortcuts is a failed system that needs to be redone. Doing it once, correctly, is always cheaper than twice.
Weeping tile that was installed thirty or forty years ago is frequently at or past the end of its functional life, even when it was installed correctly. Clay tile systems from older construction are particularly prone to joint separation and root infiltration. Concrete pipe sections crack and shift. Even corrugated plastic pipe from more recent installations can collapse if backfill was too aggressive or if the stone bed was insufficient. We camera-scope weeping tile whenever access permits during an assessment — the results frequently change our recommendation.
Homeowners who invest in proper foundation waterproofing consistently tell us it changed how they think about their home. Not just the dry basement — though that matters — but the confidence. The ability to finish the basement without worrying what's behind the wall. The ability to put valuable things in storage downstairs. The absence of anxiety every time a heavy rain system moves through in April. A properly waterproofed foundation gives homeowners back something that a leaking one quietly takes away: the sense that the home is fundamentally solid and protected.
Both approaches can produce a permanently dry foundation — but they work differently, cost differently, and suit different situations. Understanding the distinction helps you make the right choice for your home and your budget.
| Factor | Exterior Foundation Waterproofing | Interior Foundation Waterproofing |
|---|---|---|
| How it works | Seals the foundation wall from the outside — water never contacts the wall surface | Intercepts water that enters the wall and manages it before it can cause damage |
| Stops water at the source | Yes — water barrier is on the exterior of the wall | No — water still enters the wall, but is captured and removed |
| Protects foundation material from water damage | Yes — concrete never comes in contact with liquid water | Partially — wall face is still wet; floor and living space are protected |
| Addresses wall cracks | Yes — membrane covers and seals over exterior crack face | Manages water from cracks rather than sealing the crack itself |
| Addresses floor seepage | Indirectly — improved weeping tile reduces sub-slab pressure | Yes — drainage channel directly captures floor and joint seepage |
| Landscaping disruption | High — full perimeter excavation required | None — all work done inside the basement |
| Interior disruption | Minimal — all work is exterior | Moderate — perimeter floor slab is broken and replaced |
| System longevity | 20–30+ years with Duraflex membrane | Permanent with sump pump maintenance |
| Best suited for | Wall seepage, failed exterior membrane, structural concerns, or where budget and access allow | Floor seepage, floor-wall joint leaks, inaccessible exteriors, or budget-conscious situations |
| Can be combined | Yes — exterior membrane + interior drainage is the most comprehensive system available for a foundation | |
These are the questions homeowners ask us most when they call about a foundation water problem. If yours isn't here, call us — we give direct answers.
Foundation waterproofing is the application of waterproof membranes, drainage systems, and protective barriers to a home's foundation to prevent water from penetrating the structure. It includes exterior membrane application (such as Duraflex), drainage board, weeping tile systems, interior drainage channels, and crack injection. The goal is to stop water at or before the foundation wall and keep the basement permanently dry.
Dampproofing resists moisture vapour — it is the basic coating most homes received at construction, typically a tar or bituminous compound. It is not designed to resist liquid water under pressure. Waterproofing creates a true barrier against liquid water, even under sustained hydrostatic pressure from saturated soil. The Duraflex membrane we apply is a true waterproofing product. Most of the "waterproofing" that was done on homes built before the 1990s is actually dampproofing — which explains why so many of those foundations eventually develop water problems.
Signs include water stains on basement walls or floors, efflorescence (white chalky deposits on concrete), foundation cracks — especially horizontal ones — musty odours, mould on foundation walls, damp or sweating walls, and standing water after rain or snowmelt. If your home is older and has never had its exterior coating updated, it may also be relying on an aging dampproofing coat that is no longer providing meaningful protection. A free on-site assessment will give you a clear picture of where your foundation stands.
A properly installed Duraflex exterior membrane system lasts 20 to 30 years or more. Interior drainage systems are designed as permanent installations — the channel and pipe don't wear out, and sump pumps are maintained or replaced as needed, typically every 7–10 years. The longevity of any system depends entirely on the quality of materials used and the skill of the installation. A correctly applied Duraflex membrane, with proper drainage board and weeping tile, is a decades-long investment.
Costs depend on the method used, the size of the foundation, and the extent of any existing damage. Exterior waterproofing with excavation typically ranges from $10,000 to $30,000 or more for an average home. Interior drainage systems range from $5,000 to $15,000. Crack injection repairs start at a few hundred dollars for a simple crack. We provide free, written estimates with no obligation before any work begins — so you know exactly what you're committing to.
It depends on the situation. A single leaking crack in a poured concrete wall can often be addressed with targeted crack injection. If water is entering through multiple points, through the floor-wall joint, or through a broad area of the wall face, a more comprehensive approach to that section or the full perimeter is usually warranted. We assess each foundation individually and recommend only what the problem actually requires — not automatic full-perimeter work when a targeted repair is appropriate.
Interior drainage systems can generally be installed year-round since the work is inside the basement. Exterior waterproofing requires excavation — which is very difficult in frozen ground — and membrane application that requires minimum temperatures for proper curing and adhesion. We typically schedule exterior foundation waterproofing between spring and fall. If you have an urgent situation in winter, contact us to discuss what can be done immediately and what should wait for appropriate conditions.
Exterior waterproofing requires excavation around the foundation, which does affect the landscaping in those areas. We take care to protect plants and hardscaping where possible, remove and set aside topsoil, and restore the grade and surface as closely as possible to the original condition after backfilling. Large established trees near the foundation complicate exterior work and can be a factor in deciding between exterior and interior approaches. We discuss the landscaping implications clearly during the estimate.
Exterior foundation waterproofing with full perimeter excavation typically takes three to five days for an average home, depending on the perimeter length and site conditions. Interior drainage systems take one to three days. Crack injection is often completed in a single visit. We provide a realistic project timeline in your written estimate and keep you updated throughout the work.
Yes. Every foundation waterproofing project we complete is backed by a written workmanship guarantee. If the system fails due to our installation, we return and fix it at no cost to you. Warranty terms are documented clearly in your estimate before work begins — there are no surprises. We stand behind every job we do because our reputation in this community is built on exactly that.
Foundation water problems don't resolve on their own — they grow. Every season without protection is another season of pressure, freeze-thaw damage, and widening cracks. We offer a free, no-obligation site assessment so you can understand exactly what's happening with your foundation and what it will take to fix it permanently.
📞 (519) 278-5002Monday–Friday, 8am–6pm · Napanee & Surrounding Areas