Quick Answer

Basement Waterproofing Cost in London (2026)

Average cost in London

$10,030avg

$1,500 — $25,000

$50 — $300 per sq ft

+8% YoY
12 sources
Updated 2 weeks ago
Ontario

Cost Breakdown

Itemized
Labor

Excavation, installation, and backfilling

$900 — $15,000

60%

Materials

Membranes, weeping tiles, gravel, and pumps

$450 — $7,500

30%

Permits & Inspections

City of London plumbing and building permits

$150 — $500

5%

Disposal & Site Prep

Debris removal and landscape protection

$75 — $1,250

5%

🧾HST (13%) — Ontario
Base cost + $1,304 tax$11,334

HST at 13%

📋What's Included

Scope

Typically Includes

  • Interior drain tile system
  • Sump pump installation
  • Vapor barrier
  • Crack injection sealing
  • Labor

Typically Excludes

  • Exterior excavation waterproofing
  • Foundation repair
  • Mold remediation
  • Dehumidifier
  • Landscaping restoration

Based on interior waterproofing for a standard 800-1,000 sq ft basement.

🧮Estimate Your Cost

Interactive

Estimated Cost

$7,600

$6,080 — $9,120

Based on 12 sources and market data for London. Actual costs may vary depending on specific project requirements.

📈Price Momentum

Year-over-year

~1 year ago

$9,287

Today

$10,030

Basement Waterproofing in London is 8.0% compared to roughly a year ago — about $743 more on the average project.

Comparison derived from the year-over-year change rate, not a month-by-month price index. We don't store historical snapshots yet — when we do, this will become a real time series.

🏢Top Waterproofing Contractors in London

Verified providers
🔨

Advanced Basement Systems

199 Exeter Rd Unit E, London, ON N6L 1A4, Canada

4.9
★★★★½

188 reviews

🔨

Classic Waterproofing London

229 Grand Ave, London, ON N6C 1M6, Canada

4.8
★★★★½

26 reviews

🔨

London Wisecracks

135 Towerline Pl, London, ON N6E 2T3, Canada

4.8
★★★★½

25 reviews

🔨

A1 Waterproofing

3405 Scotland Dr, London, ON N6L 1P2, Canada

4.6
★★★★½

96 reviews

🔨

Ashworth Drainage

514 Hale St, London, ON N5W 1G8, Canada

4.6
★★★★½

37 reviews

Provider data sourced from public business directories. Ratings and reviews are public and may change. LookupCost is not affiliated with listed providers.

💬What People Actually Paid

Community

Common Questions

Yes, the City of London Basement Flooding Grant Program covers up to 90% of eligible costs for specific protections. Caps include $1,800 for backwater valves, $4,000 for sump pits/pumps, and $1,400 for battery backups, for a total potential grant of up to $7,200.

In 2026, exterior waterproofing typically costs between $100 and $300 per linear foot due to excavation requirements. Interior drainage systems are more affordable, ranging from $50 to $150 per linear foot.

Yes, a City of London permit is mandatory for exterior excavation and any plumbing modifications like backwater valves or new sump pump connections. Plumbing permits typically cost between $150 and $300.

A standard sump pump and pit installation costs between $1,200 and $3,000. However, with the City of London's 90% grant, many homeowners pay as little as $150 to $300 out of pocket for eligible systems.

📊Our Methodology

How we collect data
1

Aggregated from 5+ verified web sources and cost databases

2

Licensed contractor estimates and regional cost guides

3

Government construction and labor statistics

4

Community-reported project costs and reviews

Last data collection: 2 weeks ago. Updates run weekly. All costs in CAD.

About this data

Cost figures are estimates synthesized from public market data using AI research and refreshed regularly. Real project costs vary by scope, materials, contractor, and site conditions. Always get verified quotes from licensed contractors for your specific project.

Spotted bad data? Let us know — we'll review and update.