How Does Soil Cause Foundation Settlement?

Introduction

When your home was built, the ground was most likely stable. So, why is your foundation settling?

Unfortunately, while your home remains in the same position, the soil underneath it changes. Changes to the properties of this soil, like soil type and moisture content, can have an adverse effect on your home and settle your home's foundation.

But what exactly causes your foundation to settle? How does the soil get affected? Below, let's look at the three causes of foundation settlement:

Cause #1: Drying and Shrinking of Soil

Soil can dry out and shrink from two common causes: a drought or maturing trees.

Drought: After months, or even years, of no rain, clay soil dries out. When clay soil dries out, it shrinks. This creates an empty space for your home to settle into.

Maturing Trees: Did you know that the root system of a tree is two times the size of its canopy? This means, if the tree canopy hangs over your home, odds are the roots of that tree is double the size under your home. This can cause the soil underneath your home to dry out, since the roots will withdraw moisture from the soil.

Cause #2: Wetting and Softening of Soil

The more it rains, the more saturated and soft the soil gets.

Picture stepping on a muddy field. Doesn't your foot 'squish' into the soil? Your home's footer does the same, but on a larger scale.

Heavy rain can make the soil underneath the home weak, causing the home sink and your foundation to settle into it.

Cause #3: Compression of Poorly Compacted Fill Soil

When developing new neighborhoods, construction workers will commonly take the soil from hilltops and place it in valleys to create flat, buildable lots. This can become a problem over time if the soil is not compacted well.

If a home is built on top of poorly compacted fill soil, the weight of the home will cause the soil underneath it to compress, which in turn causes settlement.

Conclusion

In summary, foundation settlement occurs when the soil changes beneath your home. Whether the soil dries out from drought or tree roots, it gets too wet from heavy rains, or it compresses due to poor compaction during construction, these factors can all cause your foundation to settle. Knowing these causes helps you spot potential issues early. By staying on top of maintenance and getting professional help when need it, you can keep your home stable and secure for the long haul.