Heaving and Settling: Dealing with Common Issues in Slab Foundations

One moment, your home feels solid; the next, it’s a rollercoaster. These changes aren’t merely annoying—they represent larger issues. Cracking walls or sticky doors can indicate foundation issues. Soil shifts, the weather itself, or even bad construction can start these headaches.

Don’t sweat it, though. We’ll walk you through how to spot the signs and tackle the issue head-on. Let’s strip this down to the basics and get your foundation back under you. You got this—and Big Easy Concrete can help you manage these issues. Give us a call today, and let’s keep your foundation strong.

Understanding Foundation Heave

Foundation heave happens when the ground under a slab foundation swells and pushes the foundation upward. This swelling is mainly due to soil absorbing water, similar to how a sponge expands when wet.

Soils rich in minerals like montmorillonite, illite, and kaolinite are especially prone to this, known as expansive soils. For instance, montmorillonite can swell significantly, creating pressure on the foundation—up to 5,500 pounds per square foot!

It’s not just rain that causes this; plumbing leaks and underground water sources can also contribute, along with frost, which can make clay soils expand by about 9%.

Causes of Heaving and Settling

Foundation heaving is more common for homes with excessive moisture, poor drainage, and expansive clay soils. Settlement can occur due to soil erosion, inadequate compaction, or tree roots.

1. Impact of Soil Moisture

Soil moisture is crucial for slab foundation stability. Wet soil swells, while dry soil shrinks, causing the foundation to shift. Water sources include rain, broken drains, and runoff from construction. A major issue is the shifting water table, which can happen naturally or due to human activities.

Slab foundations, usually only 4 to 6 inches thick, are particularly vulnerable to movement from surrounding changes. Maintaining even moisture in the soil around your home—neither too wet nor too dry—is essential to prevent these issues.

2. Effects of Frost on Foundations

Frost can seriously damage foundations. When the ground freezes, water in the soil expands by about 9%, pushing the foundation up and causing frost heave. This is common in cold winter areas. If frost reaches the subsoil and thaws, it leads to more movement.

To prevent this, it’s crucial to insulate the ground or use frost-resistant materials for foundations, keeping frost from reaching deeper layers where it can cause major damage.

3. Role of Expansive Soils

Expansive soils, like clay, swell when wet and shrink when dry. They can damage foundations by pushing them up during wet periods and causing them to settle in droughts. If trees or plants that absorb water die or are removed, excess moisture can build up in the soil, leading to heaving. The ground is always changing, even if you don’t see it.

4. Influence of Hydrostatic Pressure

Hydrostatic pressure is the force from water in the soil. This pressure can be a quiet killer for foundations. When the ground is saturated with water, it increases the pressure against the foundation walls.

This can lead to cracks or even bowing of the walls. If you have a basement, you may notice signs of leaks or dampness. These problems illustrate the effects of hydrostatic pressure.

5. Tree Roots and Foundation Issues

Tree roots can help absorb water, reducing soil expansion, but they can also damage foundations by causing cracks. If trees are near your house, their roots may push against the foundation.

Removing trees eliminates their roots, which can lead to wetter soil that may cause heaving issues. It’s important to balance having plants around your home while protecting your foundation.

Treatment Options for Foundation Issues

Work to improve drainage, use root barriers, or install piers to support the foundation. These treatment options will keep the slide from getting worse.

Effective Solutions for Heaving

Heaving in slab foundations can often be caused by expansive soil and can lead to uneven floors or cracks. One way this is treated is through the use of Helical Piers. These heavy-duty steel shafts come with helical plates. They can be driven deep into stable soil layers to depths of about 100 feet. They anchor the base and block any additional upward movement. Helical Piers are the Hulk of foundation repairs—strong and dependable.

Another method is polyurethane injection, which involves injecting expanding polyurethane foam under the slab. This foam fills voids and lifts the foundation back to its original position. It’s non-invasive and fast. It cures in just 15 minutes, making it a no-brainer for minimal disruption. It’s like giving your foundation a little shove back into place.

For less severe heaving, slab jacking or mud jacking works well. This involves pumping a mixture of cement and sand underneath the foundation to lift it. You can improve your base with a natural blend. It’s ideal for areas where you want a non-chemical option.

Repair Methods for Settling Foundations

When soil beneath a structure shifts or compresses, it causes the foundation to settle. Several methods of repair will fix this problem. Instead, they commonly use push piers, which are steel tubes that push into the ground until stable soil or bedrock is reached. They support and stabilize the foundation, making them a great choice for someone needing a strong, long-lasting solution.

Steel piers provide another possibility. They are more expensive, but their strength and durability help make them a good option for serious settlement problems. They’re even able to hold hefty loads, so the foundation won’t shift once again.

In Texas, Concrete Pressed Piles (or Concrete Cylinders) are the choice. They’re used because they’re cost-effective and work with the region’s soil conditions. These cylinders are pressed into the ground, stacking on top of each other until they reach a stable layer. It’s like putting blocks on top of each other until you have something solid.

Driven about 10 feet deep and taking a week to cure, poured concrete piers are another option. This method is reliable, but it involves more time for curing, so it’s best for less urgent repairs.

Take the first step toward a safer home today!

At Big Easy Concrete, we handle repairs with the right tools and skills to get the job done right. Look out for signs like uneven floors or sticking doors, as they can signal foundation trouble. Taking action early helps protect both your home and your peace of mind.

Let’s take care of your foundation together—give us a call at Big Easy Concrete today and schedule your inspection. We’re here to keep your home safe and secure.