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GTA’s Best Exterior Basement Waterproofing Services

DrainCom is GTA’s best exterior basement waterproofing company. We excavate, seal foundations, install drainage systems and stop water permanently - licensed exterior waterproofing contractors, 25-year warranty.

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DrainCom is the

No. 1 Rated

choice for licensed and insured basement waterproofing services in Mississauga, Canada.

Water damage starts outside. Soil saturates around your foundation, hydrostatic pressure builds and water finds every crack, joint and weak point in the wall. Interior patching manages water after it arrives. Exterior basement waterproofing stops it before it ever contacts your foundation.

At DrainCom, we have been delivering professional exterior waterproofing services to homeowners in the GTA for over 20 years. We excavate to the footing, clean and repair the foundation wall, apply a high-grade waterproofing membrane and restore full drainage.

The result is a foundation that is genuinely sealed – not slowed-down with tar coating, not patched from the inside. A permanent fix backed by a 25-year transferable warranty.

Call us at 905-238-6800

for a free basement waterproofing inspection and quote or fill out the request form at the top of this page.

What Homeowners Say About DrainCom

Exterior Waterproofing vs. Damp-Proofing: What's the Difference?

Most homes in GTA built between the 1960s and 1990s were damp-proofed at construction, not waterproofed. This is a critical distinction that many homeowners do not know about until water problems start.

Damp-proofing uses a tar-based coating that slows surface moisture but cannot stop water under hydrostatic pressure. It becomes brittle as the foundation settles and cracks – and once it cracks, it fails entirely. Homeowners who dig up their foundation often find the original tar coating flaking off in chunks after 15 to 20 years, leaving cracks that need proper basement crack repair across GTA to seal for good.

True exterior foundation waterproofing uses a flexible, bonded membrane that stays adhered as the foundation moves. It is designed to hold against water pressure – not just slow moisture vapour. If your basement leaks and you were told it was “sealed” at build, damp-proofing is almost certainly what was applied.

Our recommendation: If your home is more than 20 years old and you are having persistent basement water problems, the original damp-proofing has likely failed. A proper exterior waterproofing job done now will outlast the rest of the house structure.

Exterior Basement Waterproofing Services We Cover

Exterior basement waterproofing services including excavation, membrane application, and drainage system installation

Foundation Excavation and Wall Exposure

Every exterior waterproofing job begins with excavation to the footing. We expose the full foundation wall from grade down to the base. This gives us direct access to every crack, deteriorated joint and failed membrane surface.

Our crews use proper shoring and protective measures throughout. In dense urban areas where lot lines are tight, we work carefully to protect neighbouring structures, walkways and utilities.

Exterior Foundation Crack Repair

Foundation cracks are cleaned, packed with hydraulic cement and fully sealed before any membrane is applied. Repairing foundation cracks Toronto from the outside addresses the entry point directly – the only correct approach for structural cracks that penetrate the full wall depth.

We have repaired over 10,000 foundation cracks in homes across GTA. Crack type, width and water activity all determine the method we use.

Waterproofing Membrane Application

Once the wall is repaired and clean, we apply a continuous high-grade waterproofing membrane from footing to grade. This creates an impermeable barrier across the entire exposed foundation surface.

We use materials rated for long-term ground contact and freeze-thaw performance – not tar-based damp-proofing that becomes brittle and cracks within years of application. This is the standard that separates real exterior waterproofing from a temporary coating job.

Delta MS Drainage Board Installation

A dimple drainage board is applied over the membrane to protect it from backfill pressure and direct any remaining surface moisture down toward the weeping tile. It extends membrane life significantly and adds a secondary drainage layer.

Exterior Weeping Tile Repair and Replacement

The weeping tile pipe at the footing collects groundwater and drains it away from your foundation.

We inspect, fully replace or repair exterior weeping tile Toronto during every excavation, connecting it properly to the storm drain or sump pit. A sealed wall with a failed

French Drain System Installation

For properties with poor yard drainage or high groundwater tables – common in lower-lying parts of GTA – a French drain intercepts surface and subsurface water before it reaches the foundation wall.

We design slope and discharge to move water well away from the home, preventing reaccumulation against the freshly waterproofed foundation.

Window Well Repair and Drainage

Basement window wells fill with water when drainage fails. We replace or repair window wells in the GTA and connect them directly to the weeping tile system at the footing. Water enters the well and exits through drainage – not through your window frame and into the basement.

Backwater Valve Installation (Outside)

An outside backwater valve protects your sewer lateral from sewage backflow during heavy storms. This is one of the most important flood prevention upgrades in the GTA, where combined sewer systems can surcharge during intense rainfall events.
Backwater valve installation qualifies for available municipal rebate programs. We handle all paperwork and submissions.

Parging and Foundation Wall Restoration

After sealing and membrane application, we restore the exposed above-grade foundation surface with fresh parging where needed. Parging protects against surface moisture and Ontario’s freeze-thaw cycling – a critical factor for foundation longevity in this climate.

Yard Grading and Backfilling

Backfilling is done carefully, compacted in layers and graded so surface water moves away from the foundation. Poor grading is one of the leading causes of water re-entry after exterior waterproofing. We get this step right before the job is considered done.

Exterior Basement Waterproofing Cost

Service

Approximate Cost (CAD)

Exterior Waterproofing

$150 – $400 per linear foot

Foundation Crack Repair (up to 5 ft wide / 9 ft deep)

$1,800 – $3,700

Window Well Repair (regular)

$1,900 – $3,500

Sump Pump + Tank

$2,200 – $3,500

Exterior Backwater Valve installation

$2,400 – $3,500

Weeping Tile Replacement (exterior)

Free quote – priced per linear foot

These are approximate ranges based on typical residential projects. We provide a detailed written estimate after your free on-site inspection. 

Exterior waterproofing costs more than interior waterproofing across GTA because of the excavation, wall preparation, membrane, drainage board, weeping tile and full yard restoration involved. You are paying for a complete, permanent solution to a serious structural problem.

Cost across different areas typically runs $150 to $400 per linear foot. Four main factors move the price:

  • Depth of excavation – deeper basements and taller walls require more labour and equipment
  • Foundation condition – more cracks, heavy efflorescence or damaged parging adds preparation time
  • Soil type – GTA’s clay-dense soil and some urban sites present harder dig conditions than sandy soil
  • Scope of drainage work – adding full weeping tile replacement, sump pump or backwater valve installation changes the total

City Rebate Alert: Backwater valve and sump pump installations in mississauga included as part of your exterior waterproofing project qualify for rebate programs. Mississauga homeowners can receive up to $7,500 through Peel Region programs. Toronto homeowners qualify for up to $3,400. We prepare and submit all documentation on your behalf.

What Is Exterior Basement Waterproofing?

Exterior basement waterproofing – also called outside basement waterproofing or external basement waterproofing – is the process of sealing your foundation from the outside. It stops water at the source before it contacts the basement wall.

The process involves excavating soil around the foundation down to the footing, cleaning and repairing the wall surface, applying a waterproof membrane, installing a drainage board and repairing or replacing the weeping tile pipe. The area is then backfilled and graded to direct surface water away from the home.

Unlike interior waterproofing, which manages water that has already entered your foundation’s perimeter, exterior waterproofing prevents water from reaching the wall at all. For homes in the GTA needing basement leak repair, structural crack work or fixes for failing original coatings, it is the most thorough long-term fix available.

Signs Your Home Needs Exterior Basement Waterproofing

Some basement water problems respond well to interior fixes. Others need to be addressed from the outside. Exterior waterproofing is the right call when:

Black dimple board drainage membrane wrapped around concrete foundation footing exterior GTA home
  • Water enters through cracks in the foundation wall – not the floor-wall joint or floor surface
  • Wall cracks are widening or recurring after previous interior repairs
  • The original tar-based damp-proofing is visibly flaking or failing — common in homes over 25 years old 
  • Bowing or bulging foundation walls indicate ongoing lateral soil pressure from outside
  • Efflorescence is widespread across multiple walls, not isolated to one section
  • Water intrusion continues even after an interior drainage system was previously installed
  • You are completing a major renovation and want to address the foundation properly while walls are accessible
  • You have a structural engineer’s report recommending exterior remediation

How We Do Exterior Waterproofing

Free inspection

We assess your foundation walls inside and out, review existing drainage, check for crack patterns and confirm the source and extent of water intrusion.

Permits (where required)

We obtain all required permits before work begins. All work is Ontario Building Code compliant.

Excavation

We dig to the footing along the affected walls, exposing the full exterior foundation surface. Neighbouring plants, walkways and structures are protected throughout.

Wall cleaning and crack repair

The foundation wall is cleaned thoroughly. All cracks are filled with hydraulic cement, allowed to cure and confirmed solid before membrane application.

Waterproofing membrane application

A continuous, high-grade membrane is applied from footing to grade across the entire exposed wall, creating a seamless water barrier.

Drainage board installation

A Delta MS or equivalent dimple board is placed over the membrane to protect it and channel moisture down to the weeping tile pipe.

Weeping tile repair or replacement

We inspect, repair or fully replace the exterior weeping tile pipe and connect it correctly to the storm drain or sump pit.

Backfilling and grading

We backfill with clean soil, compact in layers and slope grade away from the foundation. Your yard is fully restored.

Final walkthrough and test

We inspect all drainage connections, confirm membrane coverage and walk you through the completed work before leaving the site.

Why Exterior Basement Waterproofing Matters?

They say – A dry basement is the first mark of a safer, stronger home. Learn why exterior
basement waterproofing is your first line of defense.

Protects Your Home’s Foundation from Water Damage - DrainCom

Protects Your Home’s Foundation from Water Damage

Waterproofing prevents water from seeping into your basement, protecting your foundation from cracks, erosion, and costly structural repairs over time.

Eliminates Mould and Mildew Growth Indoors

Eliminates Mould and Mildew Growth Indoors

By stopping water intrusion, exterior waterproofing helps keep your basement dry and prevents harmful mould and mildew that can damage health.

Increases Your Property’s Overall Value and Appeal

Increases Your Property’s Overall Value and Appeal

A dry, waterproofed basement adds value and makes your home more appealing to potential buyers or future investors in real estate.

Protects Your Home’s Foundation from Water Damage

Minimizes the Need for Costly Basement Repairs Later

Effective waterproofing stops water damage early, saving you money by preventing expensive repairs to walls, floors, electrical systems, and appliances.

Exterior Basement Waterproofing Service Mississauga

Shields Stored Belongings and Valuable Items Safely

Exterior waterproofing keeps your basement dry, ensuring valuables, furniture, and stored items remain safe from water damage and deterioration.

Exterior Basement Waterproofing Service

Prevents Pest Infestations from Moist Environments

Keeping your basement dry discourages pests like termites and rodents, which are attracted to moisture and can cause additional damage.

What a Permanently Sealed Foundation Makes Possible

Exterior waterproofing protects the whole home structure – not just the basement. Here is what homeowners gain once it is done:

  • Full basement finishing with confidence – no hidden moisture risk behind drywall or insulation
  • Legal secondary suite conversion – a dry, code-compliant space eligible for a rental unit in GTA
  • Home gym, rec room or home office with zero mould or humidity concerns year-round
  • Safe permanent storage for valuables, documents and electronics
  • Complete peace of mind through Ontario’s wet spring seasons and summer storm events
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Why Choose DrainCom?

  • You're in Safe Hands with Our Licensed Pros : We're not just any waterproofing company – we're fully licensed and insured. That means you’ll be getting expert service from a team that's accountable and professional.
  • We've Been Serving Your Area for Over 20 Years : We're not some fly-by-night operation. We've been right here in Mississauga for over two decades, understanding the local climate and basement challenges.
  • Hundreds of Happy Neighbors Can't Be Wrong : Check out our Homestars and Google reviews – over 800 of them with a 9.9 rating! That's because we genuinely care about our customers and do a great job.
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Frequently Asked Questions

Most residential exterior waterproofing jobs fall between $150 and $400 per linear foot. Excavation depth, foundation condition, linear footage treated and whether drainage upgrades like sump pump or backwater valve are included all affect the total. We provide a written quote after a free inspection – no phone estimates.

It depends on the source and nature of the water problem. Exterior waterproofing is the more comprehensive fix – it stops water before it contacts the wall. Interior waterproofing service is less invasive and effective when the issue is hydrostatic pressure from below the slab or when exterior access is limited. Some homes in GTA benefit from both. We make a specific recommendation after assessing your property.

A properly installed exterior waterproofing system with a quality membrane, drainage board and weeping tile lasts 20 to 30 years or more. Our work carries a 25-year transferable warranty. Damp-proofing, by comparison, degrades within 5 to 10 years and is not a long-term solution.

There will be excavation along the foundation. We protect neighbouring plants, structures and walkways throughout and restore your yard fully when the job is complete. If a driveway or hardscaping directly against the foundation needs partial removal, we discuss and document that with you before any work begins.

Look for a licensed, insured contractor with verified local reviews, documented experience and a written warranty. DrainCom holds a 9.9/10 rating on Homestars across more than 820 reviews, has waterproofed over 20,000 homes and carries full licensing and insurance. 

Rebates apply specifically to sump pump, backwater valve and weeping tile severance installations. Most exterior waterproofing projects include at least one qualifying component. Mississauga and Peel Region homeowners can access up to $7,500. Toronto homeowners qualify for up to $3,400. We manage all paperwork and submissions for every project.

Most exterior waterproofing projects do not require a building permit on their own. Excavation near property lines, shared drainage or utility corridors may trigger requirements in certain neighbourhoods. We assess this during the inspection and obtain all required permits before starting work.

Call us at 905-238-6800 or 416-989-5757, or fill out the contact form at draincom.ca. We serve all of GTA. Same-week inspection appointments are available. Free inspection, no obligation.

You might notice damp walls, a musty smell, or even water puddles in your basement after rain. Cracks in your foundation walls on the outside can also be a red flag.

Ideally, a good exterior basement waterproofing job should be a one-time investment designed to last for many, many years – often decades!

 

Drying time depends on the specific materials used and the weather conditions. We can give you a more accurate time frame once we assess your project.

Our Service Area

905-238-6800