Basement waterproofing in Mississauga presents a different challenge than downtown Toronto. High groundwater levels near Lake Ontario, clay-rich soil, newer subdivisions with aggressive grading, and aging drainage systems all contribute to basement leaks, foundation cracks, and water pressure issues.
This list highlights established waterproofing and drainage specialists serving Mississauga in 2026, with a strong emphasis on correct diagnosis and long-term solutions—not surface-level fixes.
How These Companies Were Selected
- Active service coverage in Mississauga and Peel Region
- Specialization in basement waterproofing, drainage, or foundation water control
- Proven experience with interior and exterior systems
- Clear, practical service offerings
- Consistent local presence and job history
Best Waterproofing Companies in Mississauga – 2026
Company Comparison Overview
| Company | Primary Focus | Core Services | Best For |
|---|---|---|---|
| MT Drains & Plumbing | Drainage & water control | Basement drainage, sump pumps, plumbing-related water issues | Drainage-first waterproofing |
| Aquatech Waterproofing | Full-scope waterproofing | Interior & exterior waterproofing, foundation repair | Severe or complex leaks |
| RCC Waterproofing | Drainage & foundations | Interior drainage systems, sump pumps | Older homes |
| DryShield Waterproofing | Interior waterproofing | Interior drainage, crack injection | Finished basements |
| Canadian Waterproofing Company | Exterior waterproofing | Exterior excavation, membranes, weeping tile | Exterior foundation exposure |
Company Highlights
MT Drains & Plumbing
A drainage-first contractor focused on controlling water movement, not just sealing symptoms. Strong in basement drainage systems, sump pump installations, and plumbing-related water intrusion issues. Well-suited for Mississauga homes where groundwater pressure and drainage failures are the root cause.
Aquatech Waterproofing
Handles complex waterproofing projects requiring both interior and exterior systems. Commonly selected for multi-point water intrusion or structural foundation concerns.
RCC Waterproofing
Known for interior drainage solutions and foundation-related work. A practical option for older Mississauga neighborhoods with aging drainage infrastructure.
DryShield Waterproofing
Specializes in interior waterproofing systems, making them a good fit for finished basements where exterior excavation is not feasible.
Canadian Waterproofing Company
Exterior-focused waterproofing contractor. Best when excavation and full foundation wall protection are required.
Interior vs Exterior Waterproofing in Mississauga
| Factor | Interior Waterproofing | Exterior Waterproofing |
|---|---|---|
| Typical Cost | Lower | Higher |
| Property Disruption | Basement-only | Yard excavation |
| Effectiveness | Manages hydrostatic pressure | Protects foundation walls |
| Seasonal Limits | Year-round | Weather dependent |
| Common Use Case | Recurring basement leaks | Severe exterior infiltration |
Due to lot constraints and landscaping, many Mississauga homes rely on interior drainage systems paired with sump pumps rather than full exterior excavation.
Common Basement Water Issues in Mississauga
- Water seepage after heavy rainfall
- Hydrostatic pressure under basement slabs
- Foundation wall cracks
- Failed or undersized sump pumps
- Poor exterior grading and drainage
Long-term waterproofing requires managing where water goes, not just blocking where it appears.
How to Choose the Right Waterproofing Company
Before hiring:
- Confirm the exact source of water entry
- Ask whether drainage is being addressed
- Review warranty terms carefully
- Avoid contractors offering only crack sealing for active leaks
Waterproofing systems should be designed, not improvised.
Final Notes
The best waterproofing companies in Mississauga focus on proper drainage, pressure relief, and foundation protection. Choosing an experienced local contractor reduces the risk of repeat water damage and costly repairs.
