A house foundation must be designed and constructed to carry the house load as well as protect against external forces. Besides supporting the weight of the house it acts as a retaining wall to hold back those forces of soil and water. The foundation wall itself must be strong to withstand this external force or it will crack and shift. When a wall is overloaded from pressure such as frost heave, saturated soil, improper back filling, or other conditions, it can move laterally and bow inward often cracking. Deep foundations with constructed with concrete blocks are particularly vulnerable.
To help avoid excessive external pressure against a finished foundation, grading and drainage should be maintained to direct all water flow around and away from the home. Significant movement of a foundation will probably require replacement but slight shifting may only require repair and reinforcement. In the past such an undertaking was quite envolved but presently, carbon reinforced fibers can be used to hold the wall in place. This method is quicker, less obstructive and does not take up valuable indoor space.