Curtain grouting and crack injection are two very effective methods of stopping leaks from coming into your basement or underground structure. When there are multiple cracks or areas leaks permeate from, curtain grouting may be your best bet. Imagine a manhole entrance that is leaking from the walls, curtain grouting would go between the outside of the walls and the surrounding dirt. This effectively stops leaks from the outside and creates a waterproof shield that will not degrade.