Basement Waterproofing Cost in London (2026)
Average cost in London
$3,500 — $35,000
$70 — $350 per sq ft
Cost Breakdown
ItemizedExcavation, installation, and backfilling
50%
Membranes, weeping tiles, and sealants
30%
Sump pumps and backwater valves
10%
Landscaping and concrete patching
7%
City of London building/plumbing permits
3%
HST at 13%
📋What's Included
ScopeTypically 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
InteractiveEstimated Cost
$6,080 — $9,120
Based on 8 sources and market data for London. Actual costs may vary depending on specific project requirements.
📈Price Momentum
Year-over-year~1 year ago
$10,783
Today
$11,850
Basement Waterproofing in London is ↑ 9.9% compared to roughly a year ago — about $1,067 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 providersAdvanced Basement Systems
199 Exeter Rd Unit E, London, ON N6L 1A4, Canada
186 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 Basement Flooding Grant Program provides up to 90% reimbursement for specific measures. In 2026, caps include $4,000 for sump pumps/pits, $1,800 for backwater valves, and $1,400 for battery backups.
The City of London requires a permit for most waterproofing and plumbing work. As of 2026, the minimum permit fee is $260.37, though complex projects involving structural changes may be higher.
Interior systems typically cost between $70 and $150 per linear foot ($3,500–$12,000 total). Exterior waterproofing is more intensive, ranging from $150 to $350 per linear foot ($15,000–$35,000 total) due to excavation requirements.
Many London neighborhoods (e.g., Byron, Oakridge) have heavy clay soil. This increases labor costs for exterior projects as clay is harder to excavate and requires more clear-stone backfill for proper drainage, often adding 10-15% to the labor estimate.
📊Our Methodology
How we collect dataAggregated from 5+ verified web sources and cost databases
Licensed contractor estimates and regional cost guides
Government construction and labor statistics
Community-reported project costs and reviews
Last data collection: 4 days 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.