Why Are My Basement Walls Leaning?

Your basement walls could be leaning, bowing, or crumbling for a number of reasons. Lateral pressure due to water in the soil around your home and a damaged foundation are just two potential causes. Worse still, bowing basement walls can cause a whole host of other problems. This is why it’s best to get an expert opinion if your basement walls are bowing. 

Other potential causes of bowing or leaning basement walls include, but are not limited to: 

• Damaged Support Joists 

If joists supporting the floor above your basement are damaged, your basement walls can experience disproportionate pressure from above. While this is more likely to cause cracks, it can also cause walls to start leaning or buckling. Support joists can become damaged in a number of ways, but the most common causes of joist damage are dampness, rot, and excessive pressure (usually as a result of pre-existing structural damage in the home. 

Dampness and humidity are common culprits when it comes to joist damage because of the way they can cause exposed wood to rot. Rotting wood becomes soft, of course, and will quickly start to bend or even simply crumble. It is also very tempting for pests like termites and also for certain species of mold (which will attract other pests). So while dampness can cause damage to support joists, it is also a wider problem that should be addressed quickly.

• Foundation Subsidence and Settlement

When a property foundation begins to sink, it causes many issues, but the uneven nature of this subsidence can also make walls bow. This is because of the extreme pressure that subsidence can place on specific parts of your home. Droughts, for example, can cause the soil under your home to dry out and shrink, while flooding may cause it to become saturated and swell. Some soils react more dramatically to moisture than others. Clay-based soil, for example, can shrink and grow massively.

When these soils react to moisture they can put pressure on your property either as a result of expansion or through the removal of support during shrinking. This not only undermines the stability of your home, but it will allow water into your foundation and basement as a result of cracks forming in your walls and flooring.