Content Writer, Former Landscaping Project Coordinator
Published: February 24, 2026
The cost of exterior waterproofing for a typical Ontario home ranges from $10,000 to $35,000, with prices averaging $150 to $350 per linear foot. Interior waterproofing costs $3,000 to $10,000 for most homes, averaging $70 to $150 per linear foot.
Most Ontario homes have foundation perimeters between 100 and 150 linear feet. A 30-foot by 40-foot home has roughly 140 linear feet of foundation wall.
Exterior Basement Waterproofing Costs
Exterior waterproofing stops water before it reaches your foundation walls. Contractors excavate around your home, repair the foundation, apply waterproof membranes, and install new weeping tiles.
What’s Included in Exterior Waterproofing
Full excavation to the footer (typically 5-8 feet deep in Ontario)
Foundation wall inspection and repair
Application of rubberized or tar-based waterproof membrane
Installation of dimpled drainage membrane
New weeping tile installation around perimeter
Connection to sump pump or storm sewer
Backfill and soil compaction
Landscaping restoration
Exterior Waterproofing Cost Breakdown
Foundation Depth
Cost Per Linear Foot
Typical Total Project Cost
5-6 feet
$100-$200
$10,000-$20,000
6-8 feet
$150-$300
$15,000-$30,000
8+ feet (deep foundation)
$250-$400
$25,000-$40,000
The average homeowner in Ontario spends $15,000 to $25,000 for complete exterior basement waterproofing.
Interior Basement Waterproofing Costs
Interior waterproofing manages water that enters your basement by directing it away before it floods your space. This method installs drainage systems inside your basement perimeter.
What’s Included in Interior Waterproofing
Perimeter trench excavation along basement floor
Interior weeping tile installation
Drainage membrane applied to foundation walls
Sump pump installation or connection
New concrete floor patch over trench
Drainage system connected to existing sump or new pump
Interior Waterproofing Cost Breakdown
System Type
Cost Per Linear Foot
Typical Total Project Cost
Basic interior drainage
$50-$80
$5,000-$8,000
Full perimeter system with membrane
$70-$120
$7,000-$12,000
Premium system with backup pump
$100-$180
$10,000-$18,000
Additional costs:
Sump pump installation: $800-$2,800
Backup battery sump pump: $1,500-$3,500
Backwater valve: $1,500-$3,700
Factors That Affect Basement Waterproofing Price
Foundation depths in Toronto and the GTA typically range from 5 to 8 feet. Deeper foundations require more excavation, labour, and materials. A 6-foot foundation costs significantly less than an 8-foot or 9-foot foundation.
Each additional foot of depth can add $20-$50 per linear foot to your total cost.
Waterproofing is priced per linear foot of foundation wall. Larger homes cost more.
Small bungalow (100 linear feet): $10,000-$15,000 exterior
Average detached home (140 linear feet): $15,000-$25,000 exterior
Large two-storey home (180 linear feet): $20,000-$35,000 exterior
Bigger jobs often have lower per-foot costs due to economies of scale.
Clay soil costs 25-50% more to excavate than sandy soil. Clay is denser, retains more water, and requires more effort to dig. It’s common in Markham, Stouffville, and parts of Toronto.
Sandy soil is easier to excavate but may require extra shoring during the dig to prevent cave-ins.
High water tables increase project complexity and cost.
Tight spaces between your house and property line, fences, or neighbouring structures increase labour costs. If excavators can’t fit equipment between buildings, contractors dig by hand.
Hand digging can add 30-50% to your exterior waterproofing cost.
Contractors must remove and restore:
Interlocking patios or stone walkways
Decks and porches
Garden beds and shrubs
Driveways (if waterproofing the front or side of the house)
Landscaping restoration typically adds $2,000-$8,000 to exterior projects depending on complexity.
Most municipalities in Ontario require building permits for waterproofing work involving excavation or structural modifications.
Toronto permit fees: Base rate of $198.59 plus additional fees based on project scope.
Permit costs typically range from $200 to $800 depending on your municipality and project size.
Exterior vs Interior Waterproofing Comparison
Factor
Exterior Waterproofing
Interior Waterproofing
Cost per linear foot
$150-$350
$70-$150
Total project cost
$15,000-$35,000
$7,000-$15,000
Effectiveness
Prevents water from entering foundation
Manages water that has entered
Longevity
25-30+ years
15-25 years
Disruption level
High (landscaping, excavation)
Moderate (basement floor work)
Best for
Long-term protection, new homes
Finished basements, tight budgets
Weather dependency
Cannot work in winter/frozen ground
Year-round installation
Which Method is More Effective?
Exterior waterproofing is more effective long-term because it stops water before it contacts your foundation. It reduces hydrostatic pressure and protects your foundation walls from deterioration.
Interior waterproofing is still highly effective for keeping basements dry. It doesn’t prevent water from reaching the foundation, but it manages water efficiently once it enters the wall assembly. Modern interior systems with membranes and proper drainage keep basements completely dry.
Exterior waterproofing is the gold standard, but interior systems offer excellent protection at lower cost with less disruption.
Special Circumstances That Increase Cost
Homes with narrow side yards, adjacent buildings, or slopes require specialized equipment or hand digging. Semi-detached homes in Toronto often have less than 3 feet of clearance on one side.
Cost impact: Adds $3,000-$10,000 to the project.
Properties near rivers, ravines, or with high water tables need more robust drainage systems and continuous pumping during excavation.
Cost impact: Adds $2,000-$6,000 for dewatering equipment and extra drainage.
Older Toronto homes and custom builds sometimes have foundations 9-10 feet deep. The extra excavation depth increases labour hours and material costs significantly.
Cost impact: Adds $5,000-$12,000 compared to standard 6-foot foundations.
Removing and restoring mature trees, extensive gardens, or custom hardscaping requires specialized labour.
Cost impact: Can add $5,000-$15,000 depending on the scope.
Permit Requirements for Waterproofing in Ontario
When You Need a Building Permit
Most municipalities require permits for:
Exterior excavation deeper than 4 feet adjacent to a foundation
Structural modifications to foundation walls
New drainage connections to municipal storm sewers
Installation of backwater valves or sump pumps with discharge
When You Don’t Need a Permit
Simple waterproofing work that doesn’t involve structural changes typically doesn’t require permits:
Minor crack repairs
Interior sealant application
Above-grade membrane installation
Always check with your local building department. Requirements vary by municipality.
Permit Costs by Municipality
Municipality
Typical Permit Cost
Toronto
$200-$600
Mississauga
$250-$500
Vaughan
$200-$500
Markham
$200-$500
Durham Region cities
$200-$400
Oakville/Burlington
$200-$500
Permit fees are usually calculated based on project value or square footage. Your contractor typically handles permit applications as part of their service.
Toronto Basement Flooding Protection Subsidy
Toronto homeowners can receive up to $3,400 in rebates for:
Sump pump installation: Up to $1,250
Backwater valve installation: Up to $1,250
Severance and capping of storm sewer: Up to $900
Other GTA municipalities offer similar programs. Check with your city for current rebate availability.
The cost of exterior waterproofing for a typical Ontario home ranges from $10,000 to $35,000, with prices averaging $150 to $350 per linear foot. Interior waterproofing costs $3,000 to $10,000 for most homes, averaging $70 to $150 per linear foot.
Most Ontario homes have foundation perimeters between 100 and 150 linear feet. A 30-foot by 40-foot home has roughly 140 linear feet of foundation wall.
Exterior Basement Waterproofing Costs
Exterior waterproofing stops water before it reaches your foundation walls. Contractors excavate around your home, repair the foundation, apply waterproof membranes, and install new weeping tiles.
What’s Included in Exterior Waterproofing
Full excavation to the footer (typically 5-8 feet deep in Ontario)
Foundation wall inspection and repair
Application of rubberized or tar-based waterproof membrane
Installation of dimpled drainage membrane
New weeping tile installation around perimeter
Connection to sump pump or storm sewer
Backfill and soil compaction
Landscaping restoration
Exterior Waterproofing Cost Breakdown
The average homeowner in Ontario spends $15,000 to $25,000 for complete exterior basement waterproofing.
Interior Basement Waterproofing Costs
Interior waterproofing manages water that enters your basement by directing it away before it floods your space. This method installs drainage systems inside your basement perimeter.
What’s Included in Interior Waterproofing
Perimeter trench excavation along basement floor
Interior weeping tile installation
Drainage membrane applied to foundation walls
Sump pump installation or connection
New concrete floor patch over trench
Drainage system connected to existing sump or new pump
Interior Waterproofing Cost Breakdown
Additional costs:
Sump pump installation: $800-$2,800
Backup battery sump pump: $1,500-$3,500
Backwater valve: $1,500-$3,700
Factors That Affect Basement Waterproofing Price
Foundation depths in Toronto and the GTA typically range from 5 to 8 feet. Deeper foundations require more excavation, labour, and materials. A 6-foot foundation costs significantly less than an 8-foot or 9-foot foundation.
Each additional foot of depth can add $20-$50 per linear foot to your total cost.
Waterproofing is priced per linear foot of foundation wall. Larger homes cost more.
Small bungalow (100 linear feet): $10,000-$15,000 exterior
Average detached home (140 linear feet): $15,000-$25,000 exterior
Large two-storey home (180 linear feet): $20,000-$35,000 exterior
Bigger jobs often have lower per-foot costs due to economies of scale.
Clay soil costs 25-50% more to excavate than sandy soil. Clay is denser, retains more water, and requires more effort to dig. It’s common in Markham, Stouffville, and parts of Toronto.
Sandy soil is easier to excavate but may require extra shoring during the dig to prevent cave-ins.
High water tables increase project complexity and cost.
Tight spaces between your house and property line, fences, or neighbouring structures increase labour costs. If excavators can’t fit equipment between buildings, contractors dig by hand.
Hand digging can add 30-50% to your exterior waterproofing cost.
Contractors must remove and restore:
Interlocking patios or stone walkways
Decks and porches
Garden beds and shrubs
Driveways (if waterproofing the front or side of the house)
Landscaping restoration typically adds $2,000-$8,000 to exterior projects depending on complexity.
Most municipalities in Ontario require building permits for waterproofing work involving excavation or structural modifications.
Toronto permit fees: Base rate of $198.59 plus additional fees based on project scope.
Permit costs typically range from $200 to $800 depending on your municipality and project size.
Exterior vs Interior Waterproofing Comparison
Which Method is More Effective?
Exterior waterproofing is more effective long-term because it stops water before it contacts your foundation. It reduces hydrostatic pressure and protects your foundation walls from deterioration.
Interior waterproofing is still highly effective for keeping basements dry. It doesn’t prevent water from reaching the foundation, but it manages water efficiently once it enters the wall assembly. Modern interior systems with membranes and proper drainage keep basements completely dry.
Exterior waterproofing is the gold standard, but interior systems offer excellent protection at lower cost with less disruption.
Special Circumstances That Increase Cost
Homes with narrow side yards, adjacent buildings, or slopes require specialized equipment or hand digging. Semi-detached homes in Toronto often have less than 3 feet of clearance on one side.
Cost impact: Adds $3,000-$10,000 to the project.
Properties near rivers, ravines, or with high water tables need more robust drainage systems and continuous pumping during excavation.
Cost impact: Adds $2,000-$6,000 for dewatering equipment and extra drainage.
Older Toronto homes and custom builds sometimes have foundations 9-10 feet deep. The extra excavation depth increases labour hours and material costs significantly.
Cost impact: Adds $5,000-$12,000 compared to standard 6-foot foundations.
Removing and restoring mature trees, extensive gardens, or custom hardscaping requires specialized labour.
Cost impact: Can add $5,000-$15,000 depending on the scope.
Permit Requirements for Waterproofing in Ontario
When You Need a Building Permit
Most municipalities require permits for:
Exterior excavation deeper than 4 feet adjacent to a foundation
Structural modifications to foundation walls
New drainage connections to municipal storm sewers
Installation of backwater valves or sump pumps with discharge
When You Don’t Need a Permit
Simple waterproofing work that doesn’t involve structural changes typically doesn’t require permits:
Minor crack repairs
Interior sealant application
Above-grade membrane installation
Always check with your local building department. Requirements vary by municipality.
Permit Costs by Municipality
Permit fees are usually calculated based on project value or square footage. Your contractor typically handles permit applications as part of their service.
Toronto Basement Flooding Protection Subsidy
Toronto homeowners can receive up to $3,400 in rebates for:
Sump pump installation: Up to $1,250
Backwater valve installation: Up to $1,250
Severance and capping of storm sewer: Up to $900
Other GTA municipalities offer similar programs. Check with your city for current rebate availability.