When a house has hollow concrete block foundation walls it is very likely that water is trapped within the wall. Eventhough a CMU block wall or cinder block wall can make a structure strong, water can still penetrate and build over time which will result in a leaky basement. Before installing an interior system, we drill weep holes at the bottom of the wall. This technique allows the water that has built up in the cells of the foundation wall to drain out and relieve hydrostatic pressure from the wall.