What Are the Causes of Foundation Heave?

Foundation heave is caused by soil expansion. The most common causes of soil expansion are: 

• Excessive Saturation 

Excessive soil saturation as a result of flooding can cause soil expansion and foundation heave, but this is only when sudden freezes follow saturation. If the soil becomes saturated in warmer weather, it is far more likely that your foundation will begin to sink into the now marshy and unstable ground. As previously stated, some types of soil are more prone to saturation than others. 

Expansive soils, of course, are the main culprits, but they are not the only problem soils that can lead to frost heave. Loose backfill soil around your home can create a clay bowl of sorts when it rains. In this case, the poor drainage will make frost heave more likely should a sudden drop in temperatures cause the trapped water to freeze. 

• Tree Root Invasion 

Foundation heave doesn’t always happen because of freezing weather and saturated soil. Root invasion is one of the main ways in which foundation heave can occur without the pressure coming from the soil itself. When large trees spread their roots, they can break through sewage lines, grow into pipes, and even impact the soil directly around your foundation causing the walls to crack. 

This tends to be a much slower occurrence than frost heave because it relies on the growth of the trees and their roots. Nonetheless, tree root invasion can be incredibly destructive to your property’s foundation and unlike frost heave, they are likely to cause issues with other areas of your home too! Tree roots are notorious for ruining driveways and cracking sewage lines.