Almost every basement leak we are called to has already been patched at least once. The patch fails because water does not enter where it appears — it tracks laterally between the membrane and the substrate until it finds a crack, a service penetration or a construction joint.
The three dominant failure modes we record are: unbonded membranes allowing lateral tracking, unsealed construction joints without waterstops, and service penetrations detailed on site rather than designed.
A permanent repair therefore has to address the interface, not the visible damp patch. That usually means negative-side injection with hydrophobic polyurethane to seal the flow path, followed by a bonded cementitious crystalline system to the internal face.
Crucially, none of this can be specified without diagnosis. We map moisture, open inspection windows and trace the flow path before writing a single line of specification.