Epoxy or Urethane?
Is the repair structural in nature? Is water present? Is there soil on the backside of the wall that is being injected? These are a few of the questions that need to be answered before selecting either epoxy or urethane grout for injection. Urethane grout, for example,Requires water to be present in order to catalyze. Epoxy adhesive is typically used where a structural repair is needed.
Injection Port Spacing
Proper placement of injection ports is critical. The spacing of ports will depend on the thickness of the concrete wall or slab. For urethane grout injection, the ports need to be placed such that the injection intercepts the crack at its mid-thickness point. For example, if a wall is 6” thick, the crack needs to be intercepted where it is 3” deep.
Water is very persistent. After injecting, it is important to not only monitor the original crack that was injected, but nearby areas as well.Water will find the paths of least resistance and can sometimes be “pushed” to other vulnerable areas on the wall or floor slab and create new leaks.