Not all waterproofing materials are equal. Duraflex is the professional-grade rubberized membrane system we specify on every foundation and basement project — because it performs where other products fail. Here's why we use it, what it is, and what it means for your home.
When a waterproofing system fails, the failure usually isn't the installer's technique — it's the material that gave out. Tar-based dampproofing coatings crack. Thin spray membranes don't bond properly to damp concrete. Rigid coatings can't flex with foundation movement and develop gaps over time. The material is the system, and the system is what stands between your foundation and the water table.
At AW Waterproofing Solutions, we specify Duraflex on every project that involves a foundation membrane. Not because it's convenient — it's not the cheapest option — but because it performs. It bonds to concrete that is still damp. It remains flexible through Ontario's freeze-thaw cycles. It fills surface voids and irregularities rather than bridging over them. And it's the same material standard used in new construction by builders who understand what foundations face over 30, 40, 50 years.
Duraflex is a rubberized polymer waterproofing system applied directly to the exterior or interior face of the foundation wall as part of our foundation waterproofing services. Unlike dampproofing — which only resists moisture vapour — Duraflex is a true waterproofing membrane designed to withstand hydrostatic pressure: the force of water-saturated soil pressing continuously against the foundation wall. This distinction matters enormously in practice. Dampproofing fails under pressure. Duraflex is engineered to hold against it.
This page explains what Duraflex is, how it works, why we chose it over competing products, and how it performs in the field conditions that Ontario foundations actually face. If you're comparing waterproofing proposals from different contractors, understanding the material differences will help you evaluate what you're actually being offered.
Duraflex is not a commodity waterproofing product. Understanding its specific properties explains why it outperforms alternatives in real-world foundation conditions — and why those differences matter over the 20- to 30-year life of the system.
Duraflex is a thick, rubberized membrane — not a paint, not a tar coat, not a thin spray. Its polymer composition gives it properties that rigid coatings fundamentally cannot replicate: flexibility, elongation, and the ability to move with the structure without cracking.
Dampproofing resists moisture vapour. Waterproofing resists liquid water under hydrostatic pressure. Duraflex is the latter. It is designed to hold against the force of water in saturated soil pressing continuously against the foundation wall — the actual condition foundations face after heavy rain and snowmelt.
Most waterproofing products require a fully dry surface to bond correctly. Duraflex is specifically formulated to adhere to concrete that is still damp — a critical advantage when working with below-grade foundations that cannot always be fully dried before application.
Ontario foundations move. Soil freezes, expands, and shifts. Concrete experiences minor thermal movement year-round. Rigid coatings crack at these movement points. Duraflex remains flexible, elongating with the structure rather than cracking — maintaining the waterproof seal through decades of freeze-thaw cycling.
Foundation walls are not smooth. They have form tie holes, honeycombed areas, cold joints, and surface pitting. Duraflex fills these rather than bridging over them — creating a continuous membrane that addresses the full surface condition rather than a thin layer that leaves voids behind.
Duraflex is specified by residential and commercial builders operating to current construction standards. When a new foundation is waterproofed correctly, Duraflex or an equivalent rubberized polymer membrane is what goes on the wall. Choosing it for existing home waterproofing brings that home to the same standard.
Duraflex works as a system. A dimple drainage board is installed over the membrane, creating an air gap that protects the membrane from direct soil contact and directs water downward to the weeping tile. The membrane and drainage board are designed to function together — the drainage board cannot damage or delaminate the membrane.
When properly applied to a well-prepared surface, Duraflex membranes are designed to last 20–30 years or more. This is consistent with what we see in the field: properly installed Duraflex membranes from projects completed a decade ago are still performing as specified, without cracking, delamination, or bond failure.
The performance of any waterproofing membrane is determined as much by how it is applied as by the product itself. A quality membrane applied incorrectly will fail. Here is the process we follow on every Duraflex installation.
Duraflex performance begins with surface preparation. We remove all loose concrete, deteriorated material, and any remaining traces of old dampproofing or tar coatings from the wall face. Cold joints, form tie holes, and foundation cracks are filled and rodded before membrane application. An improperly prepared surface is the single most common reason waterproofing membranes fail prematurely — and it's entirely within the installer's control.
Loose Material Removal Crack Pre-Fill Old Coating RemovalOn particularly porous or dusty concrete surfaces, a primer coat is applied before the membrane to improve bond strength. Priming ensures the Duraflex membrane grips the wall face completely rather than partially bonding to loose surface material.
Bond Primer Porous ConcreteThe membrane is applied to the full height of the foundation wall from footing to above grade, ensuring complete coverage with no gaps, thin spots, or missed areas. Application thickness is controlled to specification — too thin and performance is compromised; Duraflex requires adequate thickness to deliver its rated flexibility and waterproofing performance.
Full Wall Coverage Controlled Thickness Footing to GradeOnce the membrane has cured, a dimple drainage board is installed over the full membrane surface. The board's dimple profile creates a continuous air gap between the soil and the membrane, allowing water to travel downward to the drainage weeping tile rather than building hydrostatic pressure against the membrane surface. The drainage board also protects the membrane from stone and soil abrasion during backfill.
Dimple Board Air Gap Membrane ProtectionWe inspect the full membrane surface and drainage board installation before any backfill is placed. Once the excavation is backfilled, the membrane is no longer accessible. This is the only opportunity to identify and correct any application issues — and we take it seriously on every project.
Pre-Backfill Check Full Surface InspectionWe chose Duraflex deliberately, after working with multiple products in the field. The reasons are practical, not promotional.
We chose Duraflex based on how it performs in the field conditions that Ontario foundations actually face: saturated clay soils, persistent frost, high seasonal water tables, and decades of freeze-thaw cycling — situations that can lead to a wet basement without proper protection. Not based on manufacturer claims alone.
Most Ontario foundations are poured concrete or concrete block, often damp below grade. Duraflex's ability to bond to damp concrete is not a feature we can do without. Alternatives that require dry surfaces are simply not realistic for below-grade work in this climate.
A rigid waterproofing coating applied to a concrete foundation in Ontario will be challenged by freeze-thaw movement from the day it's installed. Duraflex's elastomeric properties mean it accommodates this movement rather than cracking at stress points — which is why we won't use rigid coatings on foundation exteriors.
Duraflex comes with documented performance specifications for elongation, bond strength, water resistance, and service life. When we stake a written warranty on our work, we need to be confident in the material behind it. Duraflex gives us that confidence.
We hold our work to new-construction standards wherever possible. Duraflex is what gets applied to new foundations in current residential construction, including during exterior waterproofing of existing homes. Using it on existing homes brings those foundations to the same protective standard — which is what the homeowner deserves.
Every Duraflex installation we complete is backed by our written workmanship guarantee. If the membrane fails due to our application, we return and address it. We can make that commitment because we know the material's performance characteristics and trust them.
When comparing waterproofing quotes, the product being applied matters as much as the price. Here is how Duraflex compares to the alternatives you may encounter in other proposals.
| Property | Duraflex Membrane | Tar/Asphalt Dampproofing | Thin Spray Waterproofing | Hydraulic Cement Patches | Interior Sealant Paints |
|---|---|---|---|---|---|
| Type | True waterproofing membrane | Dampproofing coating | Waterproofing spray | Crack filler | Surface sealant |
| Resists Liquid Water Under Pressure | ✓ Yes | ✗ No | Partial | Partial | ✗ No |
| Bonds to Damp Concrete | ✓ Yes | ✗ No | ✗ No | ✓ Yes | ✓ Yes |
| Remains Flexible Over Time | ✓ Yes | ✗ No — cracks | Varies | ✗ No — rigid | ✗ No |
| Fills Surface Voids | ✓ Yes | ✗ No | ✗ No | ✓ Yes | ✗ No |
| Suitable for Full Foundation | ✓ Yes | Partial | ✓ Yes | ✗ No — spot repair only | ✗ No |
| Service Life | 20–30+ years | 5–15 years (degrades) | 10–20 years (variable) | Limited — cracks recur | 2–5 years |
| Used in New Construction Today | ✓ Yes | ✗ Discontinued in quality builds | Sometimes | ✗ No | ✗ No |
Years of excavating, assessing, and repairing foundations across Eastern Ontario — from Napanee to Kingston and Belleville — has produced observations that don't appear in product literature. These are the patterns we see consistently — the realities of how waterproofing products actually perform over time in Ontario soil.
We've excavated dozens of homes that had original tar dampproofing. In virtually every case, the coating had separated from the wall in sections — sometimes completely. The foundation had been unprotected for years without the homeowner knowing.
A thin spray waterproofing product applied by a previous contractor had skinned over surface voids without filling them. When we removed it, we found intact air pockets behind the membrane — voids where water had been travelling unimpeded.
One homeowner showed us photos of their previous exterior waterproofing — a product we didn't recognise — that had visibly cracked along the wall within two winters. Duraflex doesn't do that because it's not a rigid coating.
We returned to a Duraflex application we completed 7 years prior for a related repair. The membrane was in perfect condition — fully bonded, uncracked, no delamination. That's consistent with what the product is specified to do.
Hydraulic cement is a useful emergency stop, but we regularly inherit repairs where a homeowner patched a crack with hydraulic cement, the crack re-opened around the patch, and the patch itself became a leak point.
Interior sealant paints — products sold at hardware stores for wet basements — cannot withstand hydrostatic pressure. We see them bubbling off walls or failing at seams within a season of application.
The drainage board over the membrane is not optional. On a project where drainage board had been omitted by a previous contractor, the membrane had been physically abraded by angular backfill stone across 40% of the wall surface.
Surface preparation is where most contractor shortcuts happen. We've removed Duraflex applied over existing tar by another contractor — the top membrane was fine, but it had never bonded to the wall because of what was underneath.
A homeowner received three quotes: one for tar dampproofing, one for a thin spray, and one from us for Duraflex. The price difference was real but so is the product difference. You're not comparing the same thing.
Duraflex applied to a properly prepared surface in 2018 was excavated for an adjacent repair in 2024. The membrane peeled back cleanly, completely intact — exactly what a rubberized polymer membrane should do after 6 years in Ontario soil.
These are the questions we hear most often from homeowners researching Duraflex and comparing waterproofing proposals. If yours isn't here, call us — we give direct answers.
Duraflex is a professional-grade rubberized polymer waterproofing membrane applied directly to foundation walls. It is a thick, flexible, liquid-applied membrane — not a paint, tar coat, or thin spray — that creates a continuous waterproof barrier against liquid water under hydrostatic pressure. AW Waterproofing Solutions specifies Duraflex on every foundation and basement waterproofing project where a membrane is required, because it outperforms competing products in the field conditions Ontario foundations actually face: damp concrete, saturated clay soils, freeze-thaw cycling, and sustained hydrostatic pressure from groundwater.
No. Dampproofing and Duraflex waterproofing are fundamentally different products with fundamentally different performance levels. Dampproofing — typically a tar or bituminous coating — resists moisture vapour only. It is not designed to hold against liquid water under hydrostatic pressure, and it becomes brittle and cracks over time. Duraflex is a true waterproofing membrane that resists liquid water under sustained hydrostatic pressure — the actual force that foundations face from saturated soil after rain and snowmelt. Most older Ontario homes were dampproofed at construction, not waterproofed. Duraflex brings the foundation to a genuinely waterproof standard. The difference in protection is significant and the difference in longevity is even greater.
Duraflex is applied to a specified thickness that delivers the rated flexibility, elongation, and waterproofing performance of the product. Application thickness is controlled carefully during installation — too thin and the membrane's performance characteristics are compromised. Part of proper Duraflex installation is ensuring adequate, consistent coverage across the full wall surface, with no thin spots, missed areas, or holidays in the membrane. We follow the manufacturer's application specifications on every project. This is one area where an improperly trained or rushed applicator can undermine an otherwise quality product — which is why proper installer training matters.
When properly applied to a well-prepared surface by a trained installer, Duraflex membranes are designed to last 20 to 30 years or more. This is consistent with what we observe in the field: Duraflex membranes from projects we completed a decade ago remain fully bonded, uncracked, and performing as specified. Longevity depends on three factors we control directly: surface preparation quality, application technique and thickness, and drainage board installation that protects the membrane from direct soil contact and abrasion. All three are addressed on every project we complete. A Duraflex installation done correctly is a decades-long investment in your foundation.
Duraflex is specifically formulated to bond to concrete that is still damp — a significant practical advantage for below-grade foundation work where the concrete cannot always be fully dried before application. However, like all polymer membranes, Duraflex requires minimum temperatures for proper curing and adhesion. We schedule exterior membrane applications during appropriate weather conditions — generally between spring and fall in Ontario — and do not apply membranes when temperatures are at or near freezing or when rain is imminent before the membrane can cure. Interior drainage work can typically proceed year-round. If you have an urgent situation in winter, contact us and we'll discuss what can be addressed immediately and what should wait for appropriate conditions.
Drainage board is a dimple-profile plastic sheet installed over the Duraflex membrane on the exterior of the foundation wall. The dimples create a continuous air gap between the backfill soil and the membrane surface. This gap serves two critical purposes: it allows water to drain freely downward to the weeping tile at the base of the footing — rather than building up as hydrostatic pressure against the membrane — and it protects the membrane from physical abrasion by angular stone and soil during and after backfill. Duraflex and drainage board are designed to work together as a system. The membrane without drainage board faces the full weight of saturated soil and the risk of physical damage. We never omit the drainage board on exterior foundation applications. It's not optional.
Duraflex is primarily specified for exterior foundation membrane applications — applied to the outside face of the foundation wall during excavation. This is the most direct and comprehensive approach to foundation waterproofing: the membrane stops water before it ever contacts the wall face. For interior waterproofing projects, we use a drainage channel system that intercepts water entering the foundation and directs it to a sump pump — a different but equally effective approach for the right situation. The right method depends on the specific water intrusion pattern, access conditions, foundation type, and project budget. We assess every foundation individually and recommend the approach that genuinely suits the problem.
Without excavating and inspecting the exterior of the foundation wall, it's difficult to know with certainty what coating — if any — is present. As a general guide: if your home was built before the mid-2000s and has not had its exterior waterproofing updated, it almost certainly has tar-based dampproofing rather than a rubberized polymer membrane like Duraflex. Tar dampproofing has a dark, brittle, sometimes flaking or powdering appearance when excavated. Duraflex has a rubbery, flexible texture that does not crack or peel when bent. If you're uncertain what your foundation has — or whether it has any meaningful exterior protection at all — we can assess it and give you an honest evaluation of what's actually there and what condition it's in.
Duraflex carries manufacturer product specifications and published performance ratings for the membrane itself. AW Waterproofing Solutions backs every Duraflex installation we complete with our own written workmanship guarantee — if the membrane fails due to our application, we return and address it at no cost to you. Our guarantee is based on our confidence in the product's performance characteristics and our installation standards. Warranty terms are included in your written estimate before any work begins, so you know exactly what is covered before you commit to the project. We stand behind our work because our reputation in this community depends on it.
No — and this is one of the most important things to understand when comparing waterproofing proposals from different contractors. Some contractors still apply tar-based dampproofing coatings for exterior work, which costs less but provides a fundamentally inferior level of protection. Others use thin spray products that may be marketed as waterproofing but do not perform as true waterproofing membranes under sustained hydrostatic pressure. The material used is a critical part of any exterior waterproofing proposal. When you receive multiple quotes, ask each contractor specifically: what membrane product are you applying, is it a true waterproofing membrane or dampproofing, are you using drainage board over the membrane, and what is its rated service life? The answers will tell you whether you're being offered equivalent work — or simply a similar price for a significantly different product.
We don't cut corners on what goes on the wall. Duraflex is specified on every foundation waterproofing project we complete — because the material is what the warranty stands on. Call us to discuss your project and what it will take to protect your home properly.
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