Expansive Soils Create Foundation Damage
Expansive soils, clay soil, shrink-swell, and heavable soil. These are all different names for the same thing: expansive soil.
Expansive soils are responsible for more damage to buildings than any other natural hazard.
This type of soil contains minerals like smectite clays, which absorb a lot of moisture. As the expansive soil soaks up water it expands – up to 15 times its dry volume. Furthermore, the expanded soil then pushes against your foundation and creates cracks or waterproofing problems.
In fact, as the expansive soil dries, it shrinks. The soil shrinkage gives your foundation room to move around. Consequently, this extra room removes the support from your foundation and will cause cracks, settling and other foundation damage.
The pressure of expansive soils against your foundation can exceed 30,000 pounds per square foot.
Why Do Expansive Soils Grow So Much?
Expansive soils have clay minerals which expand when wet. Sulfate salts also expand with temperature changes. When the soil has a large amount of an expansive mineral or salt, it has the potential for dramatic expansion.
Therefore, these types of minerals and salts absorb more moisture than other types of minerals, making them responsible for the dramatic expansion and shrinkage you see in clay soils.
How Can I Prevent Foundation Damage?
Expansive soils soak up any available water, making it easy to take a look at the water sources around your home to determine if they are playing a part in your foundation problems. Here are some helpful tips to ensure your home is prepared.
- Check your home’s drainage: Is the discharge line pointing away from your home? Make sure that the gutter’s line is running at least seven feet away from your foundation.
- Look at your yard’s grading. The soil next to your foundation should gently slope away from your home. Additionally, this will help drain water away from your foundation and minimize potential foundation damage.
- Do you run sprinklers next to your foundation? Any sprinkler system should be at least five feet away from your home’s foundation. When you water plants that are near your home’s foundation, don’t excessively water; that may create a problem.
These easy steps can help protect your foundation, but it’s important to keep an eye out for foundation problems. In summary, if you have any other foundation problem signs, seek the opinion of a professional engineer.