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What Type of Foundation is Suitable for Clay Soil?

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Homes in different regions have different needs. The materials used will vary based on typical temperatures, humidity, and pests in the region. Builders even consider the soil a home is built on before placing the foundation. And some soils are harder to build a good foundation for than others. Clay, for example, is a difficult soil to work with. There are a lot of different types of clay, and each one behaves differently.

So what type of foundation is suitable for clay soil? If you get this question wrong, then that can have devastating effects on your home. The wrong foundation on top of clay leads to various foundation issues, and these get expensive to repair. So you need to know what makes clay so hard to build on. You need advice that can help you choose the right foundation to use on clay soil.

Read on for everything you need to know about building foundations on clay.

Issues With Clay Soil

The reason it’s so important to use the right foundation on clay is that it’s very tricky soil. It can change constantly depending on weather conditions and composition. For starters, there are different types of clay. Some are more firm than others, and this can affect how well a home’s foundation holds up. Clay tends to expand and contract a lot when exposed to moisture. This movement often causes foundations to shift and crack. This is obviously a problem for your entire house. Some clays can be moved easily, leaving gaps around your foundation. Then when it rains, water gets into these gaps. This water then pools around the foundation and seeps into it.

If you’ve ever wondered why your home needs gutters, this is exactly why. That pooling will eventually cause water to leak into your home and can even cause wood damage. When your wood rots, this creates the perfect conditions for mold and termites to enter your home. In some cases, when the clay moves it causes your floors to lean. This can cause problems for disabled people who might not be able to maneuver as well on leaning floors. And eventually, this will cause your floors to start breaking as well.

This is why it’s so important to have a strong foundation for your home. If there’s something wrong with your foundation, this can cause problems for your entire house.

Things to Consider:

Because clay can vary so much, you have to choose your foundation carefully. The following factors should be considered when you’re choosing your home’s foundation.


The first thing to consider when choosing a foundation to place on top of clay, plants are going to be important. Plantlife means moisture, and that means there’s going to be a problem with expansion and contraction. There are four different scenarios that you need to consider.

The first is that there are no plants around the foundation whatsoever. In this case, you probably don’t need to worry as much about the moisture issue.

The second is that there are trees and shrubs near the foundation. This means that you have to take steps to minimize the potential for the soil to expand and contract with moisture. This might involve creating a reinforced trench around the tree’s root zone.

The next is that there are intentions of planting trees or shrubs near the foundation after it’s been poured. This one should always be anticipated as the next owners of the house might want to do some landscaping without realizing its effects on their soil. In this case, be prepared to make similar arrangements to the second scenario.

And finally, you want to consider that there may have been trees and shrubs that were recently removed. In some cases, you still may want to use a reinforced trench. But the most important thing to do in this scenario is to make your foundation as long and deep to ensure that it stays sturdy.

Type of Clay

You also need to consider the type of clay that you’re trying to build on.

Some clays tend to be pretty firm. These clays won’t move too much, so you don’t need to worry about erosion. But they aren’t necessarily sturdy enough to handle a heavy concrete slab.

Other clays are going to be much softer. In some cases, these are going to be more like sand. That means that placing a concrete slab is completely out of the question on these clays because it will shift and sink.

These are the clays that will have the most problem with erosion. You will notice your floors leaning or gaps around your foundation. Again, these are not good features to notice about your home.

Typical Climate

Some areas are going to get more rain and humidity than others. Wind and rain are what cause the most soil erosion in any area.

If the clay you’re building on is soft, then this is going to be a big problem. Runoff is going to occur every time there’s heavy rain. This means that the chances are high that your foundation is going to get pools of water surrounding it.

It also means that foundations are more likely to tilt. On top of the damage to your flooring, tilting floors mean that the walls are eventually not going to be lined up with the roof correctly.

What Type of Foundation Is Suitable for Clay Soil?

All this means that you need a foundation that provides a few feet of space between your home and the ground. That means that concrete slabs aren’t going to be your best option on clay soil.

You also need something that’s open to prevent moisture from becoming an issue. Crawlspaces have tendencies to trap water in them and cause moisture issues. So you probably don’t want to use a crawlspace for your foundation.

So what is the best type of foundation for clay?

The answer is a pier and beam foundation. This consists of thick wooden beams that are installed deep into the ground called piers. Beams are then laid across the piers to hold up the structure above the soil.

This helps keep your home’s foundation strong by keeping rain from hitting the soil. The piers are installed deep so that they hit bedrock, so you don’t need to worry about issues with sinking.

But that doesn’t mean that you don’t need to take steps to protect your foundation. Water runoff can still slide under your home and cause soil to erode around your piers. And if this happens continuously, then then the piers can start to rot.

You should check your foundation every so often for damage no matter where you live or what kind of foundation you have. This is the best way to prevent needing expensive repairs for a very long time.

Your home will inevitably need these repairs eventually. But the longer you can keep your current foundation sturdy, the less costly it will be for you.

How Much Does Foundation Repair Cost?

When your foundation is damaged, it’s important to get it repaired as quickly as possible. The longer a damaged foundation is left alone, the more problems this can cause for the rest of the house.

The cost of foundation repair depends on how bad the damage is. The more damage there is to your foundation, the more expensive it will be to repair.

The type of damage can also impact how much repairs will cost. If your foundation is damaged in a place that’s hard to repair, then this is going to cost a lot more than any damage that’s easy to repair.

It can also depend on what type of foundation you have. In the case of pier and beam foundations, if a pier needs to be replaced, then that’s easier than needing repairs on an entire concrete slab.

It should be noted, however, that no matter what type of foundation you have, that you should expect to pay at least a couple thousand dollars. Major issues can cost homeowners up to fifty thousand dollars for repairs.

Most homeowners are going to pay around eight thousand dollars on average for a foundation repair. Remember, this is all going to depend on factors about the damage and your home’s construction.

Get Your Foundation Repaired Today

If your foundation needs repairs, then you’re no longer asking what type of foundation is suitable for clay soil. And you shouldn’t wait to get those problems fixed either.

You need experts you can trust to fix your foundation. They should understand that your home is a safe haven for you and your family. And they should be the best foundation repair in San Antonio and Austin.

That’s why you should trust the Foundation Support Specialists. We’re family-owned and operated, and we’re here to help all of our neighbors get the best foundation repair in Austin and San Antonio possible.

Give us a call and see what we can do to help you today!

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