Why Is My Retaining Wall Leaning?

If you have retaining walls on your property that seem to be leaning or bowing, there are several potential causes to consider. The main thing to keep in mind, however, is that the walls are most likely to collapse if you do not have them repaired, regardless of the cause of the damage. Nonetheless, the most common causes of damage to retaining walls are: 

• Hydrostatic Pressure 

Hydrostatic pressure, or lateral pressure of any kind, is one of the most common causes of bowing or leaning in an otherwise sturdily built retaining wall. Every retaining wall is built to withstand a certain level of pressure or weight, but many things can cause the level of pressure being exerted to tip over that threshold. 

Underground water sources and saturated backfill soil, for example, can cause the weight of the soil behind the retaining wall to exceed its load-bearing capability. If this doesn’t happen, however, the hydrostatic pressure could be compounded by the expansive force of that water as it freezes in winter. Finally, if there are no weep holes to allow water to escape the soil behind a retaining wall, damage and failure are likely. 

• Poor Design or Construction 

Another common cause of retaining wall failure is a miscalculation in the likely weight and pressure it will face at the design stage. For example, if the architect fails to account for the expansive force of soil when it is wet, the weight of water during rainfall, or the number of supports required to keep the wall straight and sturdy, the wall will quickly begin to lean. 

Likewise, if the contractors building the wall fail to install the correct number of supports or they place supports incorrectly, the wall may be unable to withstand predicted loads and pressures. Likewise, if the materials used to build the wall are substandard or damaged at the time of construction, it is likely that the wall will begin to fail.