Penetrations · Toronto & GTA
Pipe & Cable Penetration Waterproofing
Every conduit, pipe and cable that passes through a below-grade wall is a hole in the building envelope. Sealed properly it stays dry for decades. Filled with bag mix, it leaks again within months — and the water rarely reappears where it went in.
- Electrical Conduits
- Cable Penetrations
- Pipe Sleeves
- Below-Grade Walls
- Elevator Pit Penetrations
- Trench Drains
Why Penetrations Leak
A conduit or pipe sleeve creates a joint between two different materials, and that joint sits under the same groundwater pressure as the rest of the wall. There is no bond across it unless somebody built one.
Water that enters at a penetration also travels. A conduit run is a channel, and we have traced water roughly 70 m along one before it sheeted out of a ceiling box in the middle of a garage, with the vault at the far end completely dry.
Why Bag-Mix Repairs Fail Within Months
We see these sealed with ordinary bag concrete mixed on site and packed around the penetration. No bonding agent, no waterproofing layer, and nothing accounting for groundwater sitting under pressure on the far side.
That concrete shrinks, cracks and soaks, and the water works back through. The failure curve is the tell: a repair that works immediately and then degrades steadily over a few months was never sealed, it was blocked.
Interior or Exterior Repair
Where the penetration can be reached from inside, the wall section is cleaned back, parged and coated with a cold-applied polyurea-based membrane that carries well past the conduit onto sound wall.
Where the seal has to be rebuilt on the water side, we excavate to it. A single penetration roughly five feet down under grass is about two days of work and $3,000 to $4,000 in the GTA — worth specifying properly, given the cheap version routinely fails inside one season.
Our Repair Methods
How a Penetration Is Sealed
Each layer does one job. Skipping any of them puts the repair back in the bag-mix category.
Strip Back to Sound Concrete
All of the previous repair comes out, along with any loose concrete or material around the penetration. The surface is cleaned mechanically — a wire brush at minimum — because the repair only works if it is built on solid substrate.
Bonding Agent
Polyforce is applied to the prepared concrete. This is the layer that makes the repair part of the wall rather than something sitting against it — the step bag-mix repairs leave out entirely.
Hydraulic Cement, Then Bond Again
A quick-set hydraulic waterproofing cement is packed around the penetration. It sets fast and holds against active water instead of washing out while it cures.
The cement is then coated with bonding agent again, so the waterproofing layer above it has something to key into.
Cold-Applied Membrane
A cold-applied polyurea-based membrane covers the assembly and carries out onto the surrounding wall. Polyurea is moisture-insensitive, applies to vertical and curved surfaces, and adheres over the irregular shape a conduit creates.
Where the repair was excavated, the membrane is protected before backfill so it is not damaged on the way back in.
Common questions
Frequently asked questions
Why is water coming out of the electrical conduit box in our garage ceiling?
Water has entered the conduit somewhere else and travelled along the run. We have traced it roughly 70 m from the entry point to where it sheeted out.
Can a conduit penetration be sealed from inside the garage?
Often yes — the wall section is cleaned, parged and membraned from the interior. Excavation is only needed when the seal has to be rebuilt on the water side.
What does it cost to seal a cable penetration?
A single penetration about five feet down under grass runs roughly $3,000 to $4,000 in the GTA, and takes about two days.
Why did our previous penetration repair fail so quickly?
Almost always bag mix with no bonding agent and no membrane. It shrinks, cracks and soaks, and groundwater works back through within months.
Does the electrical service have to be shut off?
The work is around the conduit, not inside it, so live services are coordinated with the building rather than interrupted in most cases.
How long will the repair last?
It is a bonded, membrane-protected assembly rather than a plug, so it holds under hydrostatic pressure for the life of the materials — MTO-rated at 25 years.
Leak around a conduit or pipe?
We find where the water actually enters, strip the failed repair back to sound concrete, and rebuild the seal as a bonded, membrane-protected assembly.