Basement Waterproofing Cost in Montreal (2026)
Average cost in Montreal
$1,500 — $35,000
$100 — $350 per sq ft
Cost Breakdown
ItemizedManual or machine digging to footings
60%
Membranes, French drains, and gravel
25%
Mini-excavators and disposal bins
10%
Municipal fees and structural reports
5%
GST+QST at 14.98%
📋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
$5,888 — $8,832
Based on 12 sources and market data for Montreal. Actual costs may vary depending on specific project requirements.
📈Price Momentum
Year-over-year~1 year ago
$11,538
Today
$12,115
Basement Waterproofing in Montreal is ↑ 5.0% compared to roughly a year ago — about $577 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 Montreal
Verified providersDELTA WATERPROOFING
1155 Boul. René-Lévesque Ouest Suite 2500, Montréal, QC H3B 4P7, Canada
118 reviews
DCR Renovation & Construction Montreal
3422 Bd Décarie, Montréal, QC H4A 3J5, Canada
590 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 RénoPlex program provides subsidies for flood protection. Homeowners can receive up to $190 per linear metre for foundation excavation and $80 per square metre for waterproofing membranes, with total grants reaching $26,000 for single-family homes.
Montreal's prevalent Leda clay is highly expansive, meaning it swells when wet and shrinks when dry. This often requires deeper excavation (6-8 feet) and specialized crushed stone backfill to prevent foundation shifting, which can increase labor costs by 15-20% compared to sandy soils.
In 2026, a professional backwater valve installation typically costs between $1,600 and $3,700 CAD. However, this is a primary target for municipal subsidies, which can often cover a significant portion of the expense to prevent sewer backups during heavy rainfall.
Exterior waterproofing is the gold standard in Montreal for long-term protection, costing $100-$350 per linear foot. Interior drainage systems are a more budget-friendly alternative at $70-$230 per linear foot, often used when exterior access is restricted by narrow city lots or shared walls.
📊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: 3 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.