Quick Answer

Basement Waterproofing Cost in Montreal (2026)

Average cost in Montreal

$15,883avg

$5,000 — $45,000

$120 — $400 per sq ft

+5.2% YoY
8 sources
Updated 2 weeks ago
Quebec

Cost Breakdown

Itemized
Excavation & Backfill

Heavy machinery and site prep

$6,475 — $15,750

35%

French Drain & Materials

Piping, gravel, and geotextile

$4,625 — $11,250

25%

Waterproofing Membrane

Delta-MS or elastomeric coating

$3,700 — $9,000

20%

Labor

Specialized foundation crew

$2,775 — $6,750

15%

Permits & Disposal

Municipal fees and debris removal

$925 — $2,250

5%

🧾GST+QST (14.98%) — Quebec
Base cost + $2,379 tax$18,262

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

📈Price Momentum

Year-over-year

~1 year ago

$15,097

Today

$15,883

Basement Waterproofing in Montreal is 5.2% compared to roughly a year ago — about $785 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 providers
🔨

DELTA WATERPROOFING

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

4.9
★★★★½

113 reviews

🔨

Sous-Sol Confort

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

4.9
★★★★½

368 reviews

🔨

Akton Injection

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

4.9
★★★★½

476 reviews

🔨

DCR Renovation & Construction Montreal

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

4.9
★★★★½

585 reviews

🔨

Les Fondations Nouvelle Génération Inc.

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

4.9
★★★★½

132 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

In 2026, the cost for a professional French drain installation in Montreal typically ranges from $150 to $350 per linear foot, including excavation and membrane application.

A standard polyurethane or epoxy crack injection costs between $650 and $1,100 per crack. If exterior excavation is required for the repair, costs can rise to $1,800 - $2,400 per section.

Yes, interior systems generally cost $80 to $150 per linear foot, whereas exterior waterproofing ranges from $120 to $400 per linear foot due to the high cost of excavation and landscaping restoration.

While programs vary by borough, many Montreal municipalities offer rebates for flood prevention, such as $500 to $2,240 for sump pump and backwater valve installations to mitigate sewer backup risks.

📊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.