Under the right circumstances, crack repair can be accomplished with high-pressure injection. Injecting a crack with epoxy is a method capable of restoring the wall to original strength. This may be the right solution when the water pressure (called hydrostatic pressure) on the wall is removed and when soils are not prone to expansion and contraction like clay. The other injection material is urethane, an expanding material, that flexes and can provide a good barrier while still allowing the wall to move with soil expansion and contraction. This is often the product of choice in areas with expansive soils like in the Kansas City area.