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Waterproofing Guides 10 min read Updated: January 2025

Toronto Building Code Requirements for Basement Waterproofing 2025

Complete guide to Toronto building code requirements, permits, and regulations for basement waterproofing. Know when permits are needed, OHSA compliance, and municipal rules.

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Written by DrySpace Waterproofing

Waterproofing Professionals

Toronto Building Code Requirements for Basement Waterproofing 2025

The Truth About Waterproofing Permits in Toronto

Many Toronto homeowners are confused about permit requirements for basement waterproofing. Here’s the clear, accurate information based on current City of Toronto regulations and the Ontario Building Code.

When You DO NOT Need a Building Permit

According to the Toronto Building Department:

“A permit is not required to damp-proof or waterproof a basement unless structural changes are involved.”

No Permit Required For:

  • ❌ Exterior waterproofing membrane application
  • ❌ Weeping tile replacement
  • ❌ Dimple mat installation
  • ❌ Foundation coating or sealing
  • ❌ French drain installation (on your property)
  • ❌ Sump pump installation (interior)
  • ❌ Crack repairs (non-structural)

When You DO Need a Building Permit

Permit Required For:

  • ✅ Underpinning or lowering basement floor
  • ✅ Adding walkout entrance
  • ✅ Structural foundation repairs
  • ✅ Modifying load-bearing walls
  • ✅ Connecting drainage to municipal system
  • ✅ Creating legal basement apartment
  • ✅ Adding exterior basement entrance

Critical Safety Requirements (OHSA)

Excavation Safety - The 1.2 Metre Rule

Regardless of permit requirements, the Occupational Health and Safety Act (OHSA) mandates:

For Excavations Deeper Than 1.2 Metres (4 feet):

  • Mandatory shoring, sloping, or trench boxes
  • Daily inspection by competent person
  • Written record of inspections
  • Proper access/egress every 8 metres

This Applies To:

  • Professional contractors
  • Homeowners doing DIY work
  • Any person performing excavation

Penalties for Non-Compliance:

  • Stop-work orders
  • Fines up to $100,000
  • Personal liability for injuries
  • Criminal charges possible

Excavation Safety Requirements by Depth

DepthRequirements
0-1.2m (0-4 ft)Basic safety precautions
1.2-6m (4-20 ft)Engineered shoring/sloping required
Over 6m (20 ft)Professional engineer design required

Ontario One Call - Before You Dig

  • Mandatory for any excavation
  • Free locate service
  • 5 business days advance notice required

How to Request:

  1. Call 1-800-400-2255
  2. Online at ontarioonecall.ca
  3. Mobile app available

What Gets Marked:

  • Gas lines (yellow)
  • Hydro/electrical (red)
  • Communications (orange)
  • Water (blue)
  • Sewer (green)

Penalties: Up to $10,000 for failure to call

Municipal Variations Across GTA

City-Specific Requirements

Toronto:

  • No permit for waterproofing alone
  • Permit for structural changes
  • Drainage connection requires permit

Mississauga:

  • May require permit for excavation
  • Stricter drainage requirements
  • Check with building department

Vaughan:

  • Excavation permits often required
  • Drainage work needs approval
  • More restrictive than Toronto

Markham:

  • Similar to Toronto requirements
  • Emphasis on erosion control
  • Stormwater management focus

Brampton:

  • Permit for major excavations
  • Drainage modifications regulated
  • Conservation authority involvement

Ontario Building Code Requirements

Foundation Waterproofing (Section 9.13)

Mandatory Requirements:

  • Dampproofing minimum for all foundations
  • Waterproofing where hydrostatic pressure exists
  • Drainage layer against foundation
  • Granular backfill or approved drainage system

Specific Code Requirements:

9.13.2 - Required Waterproofing:

  • Where foundation below water table
  • Where soil doesn’t readily drain
  • For habitable basement spaces

9.13.3 - Materials:

  • Conforming to CAN/CGSB standards
  • Applied according to manufacturer specs
  • Coverage from footing to finished grade

9.14 - Drainage:

  • Foundation drainage required
  • Minimum 100mm (4”) diameter pipes
  • Slope minimum 1 in 200
  • Connected to sump or storm sewer

Professional Standards & Best Practices

Industry Requirements

Contractor Obligations:

  • WSIB coverage mandatory
  • Liability insurance required
  • ESA permits for electrical
  • Follow manufacturer warranties

Quality Standards:

  • CGSB 37-GP-52M for dampproofing
  • CGSB 37-GP-56M for membranes
  • CSA standards for drainage

Documentation Requirements

Keep Records Of:

  • Locate request confirmations
  • Daily excavation inspections
  • Material specifications
  • Installation photos
  • Warranty documents
  • Drainage outlet approval

Common Violations & How to Avoid Them

Top 5 Violations in Toronto:

  1. Excavating without locates

    • Solution: Always call Ontario One Call first
  2. No shoring for deep excavations

    • Solution: Rent trench boxes or hire professionals
  3. Connecting to storm sewer without permit

    • Solution: Get drainage permit before connection
  4. Modifying structure without permit

    • Solution: Consult building department first
  5. Improper backfill material

    • Solution: Use granular material per code

Step-by-Step Compliance Guide

For Exterior Waterproofing Project:

Week Before:

  1. ✅ Call Ontario One Call (1-800-400-2255)
  2. ✅ Verify no structural changes planned
  3. ✅ Arrange shoring if going deeper than 1.2m
  4. ✅ Notify neighbors of work

During Excavation:

  1. ✅ Wait for utility locates
  2. ✅ Mark utilities clearly
  3. ✅ Install shoring/sloping as required
  4. ✅ Daily safety inspections
  5. ✅ Maintain safe access

Installation Phase:

  1. ✅ Follow manufacturer specifications
  2. ✅ Document installation with photos
  3. ✅ Ensure proper drainage slope
  4. ✅ Use approved backfill material

Completion:

  1. ✅ Get warranty documentation
  2. ✅ Keep all receipts and records
  3. ✅ Document drainage outlets
  4. ✅ Restore grade properly

Penalties & Enforcement

Potential Penalties:

Working Without Required Permit:

  • Fine: 2x permit fee minimum
  • Stop work order
  • Forced removal of work
  • Legal action possible

OHSA Violations:

  • Individual: Up to $100,000 + 1 year jail
  • Corporation: Up to $1.5 million
  • Plus victim surcharge

Utility Strikes:

  • Repair costs
  • Service disruption fines
  • Civil liability
  • Criminal charges if injury

Professional vs DIY Considerations

When to Hire Professionals:

Mandatory Professional Work:

  • Excavations over 6m deep
  • Structural modifications
  • Municipal connections
  • Underpinning projects

Recommended Professional Work:

  • Excavations over 1.2m
  • Complex drainage systems
  • Warranty-sensitive installations
  • High water table conditions

DIY Feasible Work:

  • Surface crack repairs
  • Interior sump pump installation
  • Shallow excavations (<1.2m)
  • Gutter and grading improvements

Quick Reference Checklist

Before Starting Any Waterproofing Project:

  • Determine excavation depth
  • Check if structural changes involved
  • Call Ontario One Call
  • Arrange shoring if needed
  • Verify drainage outlet plan
  • Check municipal requirements
  • Review OHSA requirements
  • Obtain necessary permits
  • Notify neighbors
  • Document everything

Contact Information

Key Contacts:

Ontario One Call:

  • Phone: 1-800-400-2255
  • Web: ontarioonecall.ca

Toronto Building:

  • Phone: 311 or 416-392-2489
  • Web: toronto.ca/building

Ministry of Labour (OHSA):

  • Phone: 1-877-202-0008
  • Emergency: 911

Toronto Water:

  • Phone: 311
  • Drainage permits: 416-392-8000

Conclusion

Understanding Toronto’s building code requirements for basement waterproofing helps ensure safe, compliant work. Remember: while most waterproofing doesn’t need a permit, safety requirements always apply. When in doubt, contact the building department before starting work.

The key is distinguishing between waterproofing (usually no permit) and structural work (always needs permit), while never compromising on excavation safety regardless of permit requirements.

Key Takeaways

  • Early detection saves thousands in repair costs
  • Professional assessment prevents major damage
  • Regular maintenance extends foundation life

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