Masonry crack injection, also referred to as low pressure injection is needed when there is a fault, crevice or crack in a concrete or stone wall. Whether caused by an earthquake, accident or bad foundation, low pressure injection of grout into walls can be a cost effective method of repair as opposed to replacing the entire wall. It is a good idea to get cracks sealed and reinforced immediately because the longer you wait to repair the crack, the more the integrity of your structure can dwindle.