Rod Hole Injection Services

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Learn about the Rod Hole and Tie Rod injection process for stopping basement leaks.

Poured Foundation Rod Hole Repair

Rod Hole Injection:
Rod holes are created by the forming crew responsible for building your foundation wall. In order to hold the concrete forms together and to prevent bulging from the weight of wet concrete, 5/8" rods are passed through the forms from one side to the other. After the concrete is poured, the forms are stripped off and the rods are removed leaving a 5/8" hole passing through your foundation wall. The holes are then patched with a dollop of hydraulic cement usually on the inside and the outside. However, the middle of the rod hole is still a large air void. Over time, the hydraulic cement on the outside can break down due to the freeze/thaw cycle or other movement in the ground. This allows water to get into the void and eventually find its way through to the inside of the basement.

Concrete Rod Hole Injection Service Process:

Rod Hole is Drilled:
A hole is drilled into the center of the rod hole to provide a path for the injection process. A second small hole is drilled above the rod hole on an angle down into the cavity.

Epoxy Paste and Injection Port Installed:
An injection port (plastic tube) is mounted over the hole drilled in the center of the rod hole. This is afixed with epoxy thixotropic paste which, once cured, holds the port in place.

Epoxy Injection Begins:
Epoxy is injected into the mounted port from a two-tubed injecton gun with the two raw materials mixing together in a single nozzle as it is injected. When the epoxy emerges out of the smaller hole drilled above the rod hole, this provides confirmation that the hole has been completely filled.

Poured Foundation Tie Rod Repair

Tie Rod Injection:
Tie rod holes are similar to rod holes in that they too are used during the building of your foundation wall to hold the forms together during the concrete pour and cure process. The difference is, tie rods are 1/4" in diameter and they are left in the wall once the forms have been removed. Therefore, they don't leave a large air void in your wall which is good. However, tie rods are made of steel which is bad since metal corrodes in the presence of water and oxygen. As the metal corrodes, its mass decreases (i.e. it shrinks) and eventually leaves a void around the tie rod which allows water to pass through into your basement. To keep the metal tie rods dry, the builder usually applies a dollop of tar to the outside of each tie rod hole. The tar is not impervious to soil salts and therefore begins to break down within 3 to 5 years.

Concrete Tie Rod Injection Service Process:

The injection process for tie rod holes is the same as outlined above for rod holes.