Basement waterproofing in Toronto is a necessity, not an upgrade. Local soil conditions, aging foundations, and freeze–thaw cycles make water intrusion one of the most common and expensive homeowner issues in the GTA. The companies listed below are established specialists with a strong track record in basement waterproofing and drainage work across Toronto.
This list focuses on companies that do the work themselves, understand Toronto construction conditions, and offer proper waterproofing systems—not temporary fixes.
How This List Was Built
Companies were selected based on:
- Proven basement waterproofing experience in Toronto
- Specialization in waterproofing or drainage (not general renovations)
- Clear service scope and diagnostic process
- Ability to handle both interior and exterior water intrusion
- Consistent presence in the GTA market
Best Waterproofing Companies in Toronto
Company Comparison
| Company | Primary Focus | Core Services | Best For |
|---|---|---|---|
| Aquatech Waterproofing | Full-scope waterproofing | Interior & exterior waterproofing, foundation repair | Severe or recurring leaks |
| RCC Waterproofing | Drainage & structural repair | Interior drainage systems, sump pumps | Older Toronto homes |
| DryShield Waterproofing | Interior waterproofing | Interior drainage, crack injection | Finished basements |
| Omni Basement Systems | Systemized waterproofing | Interior drainage, moisture management | Turnkey solutions |
| Canadian Waterproofing Company | Exterior waterproofing | Exterior excavation, membranes, weeping tile | Exterior wall water intrusion |
| MT Drains & Plumbing | Drainage & water control | Basement drainage, sump pumps, plumbing-related water issues | Drainage-focused solutions |
Interior vs Exterior Waterproofing in Toronto
| Factor | Interior Waterproofing | Exterior Waterproofing |
|---|---|---|
| Typical Cost | Lower | Higher |
| Disruption | Inside basement only | Yard excavation required |
| Installation Season | Year-round | Weather dependent |
| Effectiveness | Controls hydrostatic pressure | Protects foundation walls |
| Common Use Case | Recurring basement leaks | Structural wall exposure |
Many Toronto homes require interior drainage systems due to lot size limitations, finished landscaping, or attached structures. Exterior waterproofing is best when foundation walls are directly exposed to groundwater infiltration.
Common Waterproofing Problems in Toronto Homes
- Water seepage through foundation cracks
- Basement leaks after heavy rainfall
- Hydrostatic pressure under basement slabs
- Failed or missing weeping tile systems
- Inadequate or aging sump pump setups
Proper waterproofing addresses water management, not just visible moisture.
How to Choose the Right Waterproofing Company
Before hiring:
- Confirm how the water is entering the basement
- Ask why a specific solution is being recommended
- Verify warranty coverage and exclusions
- Ensure the company specializes in waterproofing, not general repairs
Companies that only offer a single solution rarely solve complex water issues.
Final Notes
The best waterproofing companies in Toronto focus on diagnosis first, system-based solutions, and long-term performance. Choosing an experienced waterproofing contractor reduces the risk of repeat failures, structural damage, and unnecessary repair costs.
This guide reflects current waterproofing practices and contractor capabilities in Toronto as of 2026.
