Did a full interior waterproofing system in my Leslieville semi last fall. Sharing the details since I had trouble finding real Toronto-specific cost and process info when I was researching.
The situation: 1920s brick semi with a partial block foundation. Been seeing seepage along two walls during heavy rain, some efflorescence on the east wall for years.
What we did: Interior drainage channel around the full perimeter (approx 65 linear feet), 3/4" dimple membrane on all walls, new weeping tile in gravel bed at footing, single sump pit with Zoeller 1/3HP pump + battery backup.
Who we used: A company that’s been doing Toronto waterproofing for about 20 years. Not naming them yet until we see how the warranty service holds up — will update after the first wet spring.
Cost: $11,200 all in including HST. No permit required for interior drain system (confirmed with Toronto Building).
First test: Had a major rainfall event in March. Zero seepage. The sump ran for about 3 hours during the peak of the storm. Previous equivalent event would have had 2-3 inches of standing water.
What I’d do differently: Installed a water alarm in the sump pit but wish I’d also done a Wi-Fi connected level sensor so I get a phone alert if the pump fails when we’re away.
Questions welcome — happy to share more about the process and contractor vetting.