What Causes Foundation Walls to Fail?
While there are a number of causes for cracked, bowed and leaning foundation walls, the most common is excessive pressure from the soil outside the wall. When expansive clay soil absorbs moisture, it swells and applies pressure that often exceeds the wall’s design capacity. In addition to expansive clay soil, excessive pressure is often the result of a failed or compromised foundation drain system and a buildup of moisture behind the wall. Again, this additional hydrostatic (water) pressure often exceeds the wall’s design capacity, leading to wall deflection. Poor surface grading and drainage is another factor that leads to the buildup of hydrostatic pressure. Excessive wall deflection, evidenced by wide cracks, bowing and leaning, can reduce the structural integrity of the wall. When the wet cycles are repeated, as in the above two scenarios, this causes further weakening and inward wall movement. Other common causes of wall failure include soil expansion due to frost, large tree root
