Quick Answer

Basement Waterproofing Cost in Montreal (2026)

Average cost in Montreal

$9,775avg

$1,500 — $28,000

$100 — $350 per sq ft

+4.5% YoY
8 sources
Updated 4 days ago
Quebec

Cost Breakdown

Itemized
Labor & Excavation

Manual and mechanical digging

$4,160 — $12,600

45%

Materials

Membranes, PVC pipes, gravel

$2,775 — $8,400

30%

Equipment & Disposal

Mini-excavator rental and soil removal

$925 — $2,800

10%

Sump Pump & Plumbing

Installation and backwater valves

$925 — $2,800

10%

Permits & Inspections

Municipal fees and engineering

$465 — $1,400

5%

🧾GST+QST (14.98%) — Quebec
Base cost + $1,464 tax$11,239

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

$9,354

Today

$9,775

Basement Waterproofing in Montreal is 4.5% compared to roughly a year ago — about $421 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
🔨

Sous-Sol Confort

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

5.0
★★★★★

358 reviews

🔨

DELTA WATERPROOFING

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

4.9
★★★★½

112 reviews

🔨

Akton Injection

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

4.9
★★★★½

458 reviews

🔨

DCR Renovation & Construction Montreal

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

4.9
★★★★½

587 reviews

🔨

Les Fondations Nouvelle Génération inc.

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

4.9
★★★★½

129 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 financial assistance for flood protection work, including the installation of backwater valves and sump pits. Additionally, the Rénoclimat program offers grants for foundation insulation and sealing that can offset costs by $200 to $2,000.

For residential buildings, the minimum permit fee is $167.40. However, the total cost is calculated at $9.80 for every $1,000 of estimated work. For a typical $15,000 exterior project, expect to pay approximately $314 for the permit.

Iron ochre is common in certain Montreal soils (like the North Shore). Specialized French drain systems designed to resist clogging from iron bacteria typically cost 25-30% more than standard installations, ranging from $125 to $400 per linear foot.

Exterior waterproofing is the gold standard in Montreal due to the freeze-thaw cycles. While interior systems are cheaper ($70-$230/linear ft), exterior excavation ($100-$350/linear ft) protects the foundation wall itself from structural damage caused by water expansion in winter.

📊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: 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.