After two years of seasonal water in my East York basement, we finally committed to an interior French drain system. Here’s an honest account of the experience.
The problem:
- Water seeping through the base of the foundation walls in spring and after heavy rain
- One corner consistently damp, leaving efflorescence and a musty smell
- Previous owner had painted the walls with “waterproof” paint — which just masked the moisture
What we got quoted:
- Exterior waterproofing (excavate around foundation, membrane + drainage board): $22,000–$35,000
- Interior drainage system (French drain + sump pump): $9,500–$14,000
- Crack injection only: $1,200–$2,500 (contractor said this wouldn’t fully solve our issue)
What we chose:
Interior system. The disruption of excavating a mature garden with decades-old perennials wasn’t something we wanted, and the interior system addresses the same symptom (water infiltration) by managing it rather than stopping it at source.
The work:
3-day job. Concrete cut along perimeter, drain channel installed, new sump pit, battery backup pump, drain outlet to municipal storm at the road. Concrete patched.
Result: First spring post-install we had zero water. Sump ran twice during heavy rain events. Completely worth it.
LF Builders (lfbuilders.ca) was one of the contractors I quoted — professional assessment and competitive pricing on waterproofing. Final choice was based on who was available soonest.
Has anyone compared interior vs. exterior in a similar East York/older Toronto home situation? home.renovation.reviews