The Threat to Your Foundation from Expansive Clay Soil

Jan 17, 2018

Soil with a high clay content can be a major headache for homeowners, especially those in Georgia, California, Colorado, Texas and the Dakotas. Why? If the ground contains expansive clay, it is subject to shrinking and expanding with the seasons, leading  to soil movement and, ultimately, the movement of any structures built on top of it.  This can cause serious issues to a home’s foundation, leading to damage that often requires extensive and costly foundation repair.

Choose Contractors Carefully

If you live in one of the above states, and suspect your home has foundation problems, it is important to consult a foundation contractor who understands expansive clay soil, knows how to test for clay levels, and can provide you with solid, informed advice about what to do to remedy the problem.

The Benefits (and Drawbacks) of Backfilling

When you’re dealing with expansive clay soil, one solution that your contractor might offer is backfilling. Backfilling involves separating foundations walls from the movement of the soil so that the walls are not affected by the movement. Usually, the backfilling material of choice is either gravel or a more stable soil. Backfilling is extremely effective when done correctly but it’s also quite costly. If your contractor presents this option to you, remember to ask whether there are other less costly options available.

Maintaining Moisture Levels

When backfilling isn’t an option or in your budget, an alternative solution is to take steps to keep the soil’s moisture level constant, since it is the shifts in moisture levels that causes foundation problems. There are many different methods and strategies for maintaining moisture levels, and you can talk with your contractor to find the best solution to match your needs and your budget.

Another option is boring beneath the home to install a perforated pipe. This type of foundation drainage system can help to prevent water from entering the basement wall, and keep water away from the footing. The pipe should run to a storm sewer. If the area around the pipe is particularly moist, you may need to fill it in with crushed stone as well.

There are also some basic measures to take to keep your soil’s moisture level constant. Keep trees and plants away from the foundation. Water naturally pools in these areas and roots from trees are notorious for growing into the foundation, as well as for breaking through water and sewage pipes, which can cause additional moisture problems.

Check that your gutters and downspouts do not drain around the foundation as well. If you find that there is water pooled around the exit of the gutter system, you may need to have a drainage solution implemented. Gravel around the perimeter of a home can help with drainage concerns, and can even assist with storm water runoff when necessary.