Our Hamilton 1960s poured concrete basement had three vertical cracks — two of them actively leaking during heavy rain. Got them injected last fall. Sharing the process and results.
Diagnosis:
- Crack 1 (south wall): 2.3mm wide, 4 ft long, actively weeping during/after heavy rain
- Crack 2 (south wall, adjacent): 1.8mm wide, 3 ft long, same wet pattern
- Crack 3 (east wall): hairline crack, 2 ft long, always dry
What the contractor recommended:
- Cracks 1 and 2: polyurethane injection (active moisture present, needs flexible seal)
- Crack 3: epoxy injection (dormant crack, restore structural monolithic integrity)
This matched my own research — I was glad the contractor said the same thing independently.
Process:
- Surface ports drilled at 8-inch intervals along each crack
- Surface sealed with hydraulic cement between ports
- Low-pressure injection of material through each port in sequence
- Let cure overnight
- Ports cut off, surface patched
Cost:
- Cracks 1 and 2 (polyurethane): $650 each = $1,300
- Crack 3 (epoxy): $480
- Total: $1,780
Results:
Two heavy rain events since injection — zero water in basement. Crack 3 was cosmetically fine before and is now sealed.
The contractor offered a 10-year warranty against water infiltration through the injected cracks. Not a lifetime warranty, but 10 years is meaningful for this type of work.