The structural integrity of your home’s foundation depends a lot on the soil on which the foundation is placed. Not all of a foundation’s strength depends on the foundation type and the building materials used. Soil matters, and while it isn’t something we can always control, understanding how soil impacts a foundation is critical.
There are several types of soil on which you can build a foundation. These include:
In Alabama, you see all of these variations. Geography plays a role, but even within a certain area you can get a few different types of soil.
One of the characteristics that makes one type of soil different from the other is how it handles moisture. As we’ve discussed previously on this blog, moisture plays a major role in the stability of your soil and foundation. It all has to do with how the soil shrinks or expands when subjected to moisture, and how the soil retains its structure.
We need to know the characteristics of that particular soil type so we can predict how it will affect the foundation. When soil expands, it pushes against the foundation; when it shrinks or retracts, it can leave gaps that the foundation will want to fill.
For example, sand, clay, and gravel shrink whenever they are dry. This creates the aforementioned space that will cause shifting and settling. A lot of times with homes that face foundation damage, the builders didn’t take the soil into consideration and build the foundation that resists this shrinkage.
The Best Soil Types for Foundations
Generally speaking, the best soil types on which to build a house are loam and rock. Rock is solid and handles moisture well, better than sand or gravel. Loam is similarly sturdy and stable with the presence of moisture.
For other types, drainage will probably need to be incorporated into the home’s design. Some types are very difficult to build on, such as sand, and should be avoided whenever possible.
If your home has foundation damage, or you suspect you may have foundation problems due to cracks in your walls, doors and windows that aren’t opening or closing properly, or uneven floors, contact the foundation specialists at Southern Home.