Interior Basement Waterproofing Company in The GTA

GTA's trusted interior basement waterproofing company. We stop leaks, install drainage systems and sump pumps from inside your home - no full excavation, 25-year warranty, free inspection.

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DrainCom is the

No. 1 Rated

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

Water in your basement is not a seasonal nuisance. It is a warning that your foundation is under pressure. Left unaddressed, moisture weakens concrete, feeds mould and drives down property value.

At DrainCom, we have been diagnosing and fixing basement water problems across the GTA for over 20 years. Interior basement waterproofing is our specialty – a permanent, minimally invasive fix that stops water intrusion from inside your home.

No full excavation. No tearing up your yard. We come to your property, identify the root cause and apply the right internal waterproofing solution 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

Interior Basement Waterproofing Services We Cover

interior-basement-waterproofing

Interior Drainage System Installation

We break the concrete along your basement perimeter, install a filtered weeping tile pipe with gravel bedding and route water away from your foundation. This is the core of any internal waterproofing solution.

It relieves hydrostatic pressure before it cracks or bows your walls – addressing the cause, not just the symptom. We use high-grade plastic weeping tile, not older clay systems that collapse and are root-invasive. 

Delta MS Drainage Membrane

Applied directly to interior foundation walls, this dimple-profile membrane channels seeping water down into the drainage pipe below. It creates a secondary barrier that keeps the wall surface completely dry year-round.

Sump Pump Installation and Repair

Every interior drainage system needs a reliable sump pump to remove collected water. We install and service submersible and pedestal sump pumps, plus battery backup systems for power outage protection.

A functioning sump pump is your last line of active defence against basement flooding. We size every unit correctly for your property – matching horsepower and gallon-per-hour capacity to your actual water load.

Backwater Valve Installation

During heavy storms, sewage can push back into your basement through the floor drain. A backwater valve stops that from happening. It is one of the smartest flood prevention investments a homeowner can make.

Our backwater valve installation across the GTA qualifies for city and regional rebate programs. We manage the application process for you from start to finish.

Interior Foundation Crack Repair

Hairline and structural cracks in poured concrete or block walls are sealed from the inside using epoxy injection, polyurethane foam or hydraulic cement. We choose the method based on crack type, width and whether water is actively flowing.

Crack repair is always paired with the correct waterproofing treatment to stop recurrence – not just patched and left to reopen.

Weeping Tile Repair and Replacement

Old clay or ABS weeping tile pipes crack, root-invade and collapse over time. We repair or replace interior weeping tile using camera inspection to confirm the failure point first. This avoids unnecessary excavation while giving you a confirmed, permanent fix.

Get Weeping Tile Service→

French Drain System Installation

For basements with high groundwater or poor drainage, an interior French drain system intercepts and redirects water before it reaches your foundation slab or walls. We design each system to the specific drainage profile of your property.

Window Well Repair and Drainage

Basement window wells fill with water when their drainage fails or is unconnected. We repair window wells throughout the GTA, clearing or replacing the drain and connecting it directly to the weeping tile at the footing so water exits safely instead of entering through the window frame.

Interior Basement Waterproofing Cost

Interior waterproofing cost across GTA typically ranges from $100 to $240 per linear foot. The final price depends on:

  • Perimeter length and depth of excavation required
  • Foundation type – poured concrete, concrete block or stone
  • Condition of existing drainage pipes and weeping tile connections
  • Whether sump pump or backwater valve installation is included in the scope

All prices above are approximate. We provide a detailed written quote after your free on-site inspection. The price you receive is the price you pay – no change orders once work begins.

City Rebate Alert: Sump pump and backwater valve installations qualify for basement flood prevention rebates. Some area homeowners can receive up to $7,500 through Peel Region programs. A few homeowners qualify for up to $3,400. We manage all documentation and submissions on your behalf.

Service

Approximate Cost (CAD)

Interior Waterproofing

$100 – $240 per linear foot

Sump Pump + Tank

$2,200 – $3,500

Sump Pump Unit Only

$900 – $1,200

Sump Pump Battery Backup

$1,280 – $1,600+

Backwater Valve (Inside Installation)

$2,200 – $2,700

Foundation Crack Repair

$1,800 – $3,700

Window Well Repair (Regular)

$1,900 – $3,500

What Is Interior Basement Waterproofing?

Interior basement waterproofing – also called internal waterproofing or interior foundation waterproofing – manages water intrusion from within the basement. It is the right solution when exterior excavation is not practical.

Instead of digging around the outside of your foundation, we work from the inside. We install a drainage network along the perimeter, apply membrane to the walls and connect everything to a sump pump. Water that would otherwise build pressure against your foundation is captured and safely discharged away from the home.

This method also collects groundwater rising from under your concrete slab – something exterior waterproofing in the GTA cannot address on its own. For homes with high water tables or clay-dense soil, interior waterproofing is often the most effective long-term fix available.

Signs Your Basement Needs Interior Waterproofing

Ontario’s spring snowmelt, summer storms and freeze-thaw cycles put serious pressure on residential foundations. Watch for these signs:

  • White chalky powder (efflorescence) on concrete walls – free lime leaching from moisture damage
  • Musty or earthy odour even when no water is visible
  • Damp or wet concrete floor after rain or snowmelt
  • Hairline or structural cracks in foundation walls
  • Mould or dark staining at the base of walls or along the floor-wall joint
  • Standing water near the floor drain or pooling in corners
  • Peeling paint or bubbling drywall anywhere in the basement
  • Sump pump running excessively or cycling too frequently
How to Fix a Leaky Basement Wall from The Inside Advice for Toronto Area Homeowners

Any one of these is a reason to call us. We offer a free basement inspection – no obligation, no pressure. A trained DrainCom technician visits your property, assesses every corner and gives you a straight answer on what is happening and what it will take to fix it.

How We Do Interior Waterproofing

Free inspection

We assess your basement for leaks, moisture sources, cracks and drainage issues. We find the cause, not just the symptom.

Area preparation

We protect your belongings and cover the work area. Your home stays clean throughout the job.

Perimeter drainage

We cut the concrete perimeter, dig to the footing and install a filtered plastic weeping tile pipe bedded in clear gravel.

Delta MS membrane

Applied to interior foundation walls to channel water down into the new drainage pipe below.

Sump pump

Collected water routes to a sump pit. The pump discharges it safely away from your foundation.

Crack sealing and concrete restoration

All cracks and joints are sealed. New concrete is poured over the drainage system. The space is left clean.

Benefits of Interior Basement Waterproofing

Our interior waterproofing services offer many benefits that provide your home with superior protection against water damage.

Prevents Water Damage to Foundation

Prevents Water Damage to Foundation

Our interior waterproofing services are designed to direct water away, preventing basement flooding and minimizing water damage to your foundation.

Increases the Property Value of Your Home

Increases the Property Value of Your Home

Interior waterproofing not only protects your home from water damage but also increases its property value by ensuring long-term value and reducing repair costs.

Protects Your Home’s Structural Integrity

Protects Your Home’s Structural Integrity

Interior waterproofing ensures the overall strength and stability of your home by preventing issues caused by water infiltration.

Improves Indoor Air Quality

Improves Indoor Air Quality

Waterproofing keeps your basement dry and secure from moisture, further eliminating mold, mildew, and odour, while improving indoor air quality.

Prevents Hydrostatic Pressure Buildup

Prevents Hydrostatic Pressure Buildup

Systems like French drains and sump pump installation in the GTA prevent the buildup of hydrostatic pressure, which could cause significant cracks or weak spots in your foundation.

Improves Energy Efficiency in Your Home

Improves Energy Efficiency in Your Home

When your basement is dry and there’s no moisture buildup, it maintains a consistent temperature throughout your home and reduces the need for excessive cooling or heating.

What You Can Do With a Dry Basement

A waterproofed basement is not just a fixed problem – it is usable square footage. Here is what homeowners do with theirs:

  • Finished living room, rec room or home gym
  • Legal secondary suite for rental income – a real asset in Ontario’s housing market
  • Home office – quiet, dry and completely separate from the main floor
  • Safe long-term storage for documents, electronics and furniture
  • Laundry room or utility space with reliable drainage

Why Choose DrainCom?

DrainCom team receiving HomeStars Best of 2016 award for top-rated basement waterproofing GTA

Top Rated Waterproofers just a call away!

Business Hour:
Monday to Friday: 8a.m -9p.m
Saturday and Sunday: 9a.m – 2p.m

Frequently Asked Questions

Interior waterproofing typically runs $100 to $240 per linear foot. Total cost depends on perimeter length, foundation type and whether a sump pump or backwater valve is included. We always provide a written quote after a free inspection before any work begins.

Most jobs take one to three days, depending on the basement size and scope. Projects that include sump pump installation in mississauga and backwater valve may take an additional half-day. We confirm a timeline during the inspection so you know exactly what to expect before we start.

Yes – it is often the best fit for older homes. The method works on poured concrete, concrete block and stone foundations. We have successfully waterproofed thousands of homes built before the 1970s.

Rebates apply to sump pump and backwater valve installations included as part of your waterproofing project. Programs vary by municipality. Homeowners can receive up to $3,400 through the City of Toronto program. Mississauga and Peel Region homeowners can receive up to $7,500. We handle all applications and documentation for you.

Most of our interior basement waterproofing services come with a 25-year transferable warranty. When you sell your home, the warranty passes to the new owner..

DrainCom serves homeowners across many areas near you. Call 905-238-6800 or fill out our contact form for a free inspection. We come to you.

Yes. Our crew seals off the work area completely, works efficiently and removes all debris before leaving. Most homeowners carry on with their day without disruption. The work area is left clean and ready to use when we are done.

Yes, it’s different. Interior waterproofing refers to addressing water intrusion from within the basement using systems like French drains, sump pumps, etc. But exterior waterproofing prevents water from reaching the foundation by installing barriers or drainage systems outside the home.

Do you notice dampness, water stains, or musty odours in your basement? Or, do you experience water flooding during heavy rains? If yes, your basement probably requires waterproofing.

Our company is known for providing reliable and permanent waterproofing services. However, if you notice any issues in the future, there’s no need to worry as we offer a 25-year warranty on our services, saving you from additional costs.

905-238-6800