Why Cracks Appear in Basement Walls

Many people are alarmed when they are in their basement and notice cracks in the foundation walls. They wonder what could have caused those cracks, and they want to know what can be done about the problem. This article discusses some reasons why foundation walls crack, resulting in water leaks into your basement.

Soil Saturation

Footings hold up the foundation of your home. The foundation supports the entire home. When it rains, water is absorbed by the soil underneath the foundation. That soil can become so wet (saturated with water) that it heaves. That pressure can cause the foundation above it to move, causing cracks in the foundation walls.


The soil underneath the foundation can also lose most of its moisture content due to several factors. For instance, a prolonged drought can cause the soil to dry up. Trees can also consume most of the water in the soil underneath the foundation. When this water is lost, the soil will shrink and cause the foundation to settle. This will result in the formation of cracks that will be visible in your basement.

Development of Stress Points

Each time the concrete in your house or foundation is drilled for different purposes (such as installing drains or electrical systems), it develops points of weakness that can develop into cracks over time. Those cracks can spread into the foundation and create a waterproofing problem.

Concrete Shrinkage

Concrete mixes contain large amounts of water. As the concrete slowly cures, it may lose most of that water content. That moisture loss reduces the total volume of the concrete, causing it to shrink in size. This shrinkage can result in foundation wall cracks since the foundation walls will be strained by the concrete that has shrunk beneath it. Those cracks will be visible when you are in your basement.

Concrete Pouring Defects

A cold joint can form when two layers of concrete are separated because the second layer was poured after the first layer had started to harden. This prevents the concrete from being homogenous. The thin line between those two layers can allow water ingress. That water may later expand (when it freezes) and cause the foundation to heave and crack.

Anything that causes a crack in the foundation will result in a waterproofing problem. This is because the crack will create an entry point for water to get into your basement. The best approach you can take when this happens is to contact a commercial waterproofing professional. He or she will conduct a comprehensive inspection of your foundation before recommending an appropriate waterproofing solution for your home.