Quick Answer

Basement Waterproofing Cost in Montreal (2026)

Average cost in Montreal

$7,500avg

$3,000 — $15,000

$5 — $10 per sq ft

+4.5% YoY
6 sources
Updated today
Quebec

Cost Breakdown

Itemized
Labor

Excavation and installation

$1,500 — $7,500

50%

Materials

Membranes, sealants, pipes

$1,050 — $5,250

35%

Equipment

Machinery and disposal

$300 — $1,500

10%

Permits

Municipal permits

$150 — $750

5%

🧾GST+QST (14.98%) — Quebec
Base cost + $1,124 tax$8,624

GST+QST at 14.98%

📋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

$7,360

$5,888 — $8,832

Based on 6 sources and market data for Montreal. Actual costs may vary depending on specific project requirements.

🏢Top Waterproofing Contractors in Montreal

Verified providers
🔨

Sous-Sol Confort

4430 Bd Dagenais O, Laval, QC H7R 1L5, Canada

5.0
★★★★★

352 reviews

🔨

DELTA WATERPROOFING

1155 Boul. René-Lévesque O Suite 2500, Montréal, QC H3B 4P7, Canada

4.9
★★★★½

111 reviews

🔨

Akton Injection

Rue Elm, Baie-d'Urfé, QC H9X 3R8, Canada

4.9
★★★★½

435 reviews

🔨

DCR Renovation & Construction Montreal

3422 Bd Décarie, Montréal, QC H4A 3J5, Canada

4.9
★★★★½

595 reviews

🔨

Les Fondations Nouvelle Génération inc.

123 Rue des Frênes, Saint-Zotique, QC J0P 1Z0, Canada

4.9
★★★★½

125 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

On average, homeowners in Montreal pay between $3,000 and $10,000 for standard basement waterproofing. However, extensive exterior excavation and French drain installations can push costs between $15,000 and $30,000.

The cost typically ranges from $5 to $10 per square foot. Interior solutions are generally on the lower end, while exterior waterproofing with excavation falls on the higher end.

Interior waterproofing in Canada averages $70 to $230 per linear foot, whereas exterior waterproofing, which involves digging around the foundation, costs between $100 and $300 per linear foot.

Yes, significant foundation work and exterior excavation require municipal permits in Montreal. Renovation permits typically cost between $500 and $2,000 depending on the project's scope.

📊Our Methodology

How we collect data
1

Aggregated from 6+ 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: today. Updates run weekly. All costs in CAD.