Has My Slab Foundation Moved?

What is a Slab Foundation?

Slab foundations, also known as monolithic or mono slab foundations, are single-piece concrete slabs that rest directly on the ground. These foundations are favored for their cost-effectiveness, being among the most affordable foundation types available.

The design of a slab foundation eliminates the need for a crawl space, reducing concerns about pests and mold beneath your home. Its singular construction minimizes the presence of weak spots, enhancing its durability and stability.

Predominantly found in warmer climates, slab foundations are less suited to areas where the ground undergoes frequent freeze-thaw cycles, as this can lead to cracking. Similarly, significant underground shifts can also cause cracks. Recognizing the signs of movement in your slab foundation is crucial for maintaining the integrity of your home. Let’s explore how to detect if your slab foundation has moved and identify the underlying causes of these issues below.

Signs and Symptoms of Slab Foundation Movement

Several signs can indicate your slab foundation has moved. Movement should be addressed by a professional right away. If you see any of the following signs, contact your trusted foundation expert right away.

Cracks and Gaps in the Walls

As the ground moves, your slab foundation shifts. This causes the amount of pressure placed on the rest of your house to change as well. This can result in cracks in your walls, even if they are made out of solid concrete. Cracks in walls aren’t always an indication of foundation issues, but larger cracks, those at 45-degree angles, or those with zigzag patterns are a definite cause for concern.

Gaps are another symptom of foundation movement, especially when they occur in your window and door frames or between your crown molding and ceiling. Gaps around windows and doors can let cold or hot air inside, making your HVAC system work harder and use more electricity. They can also allude to foundation problems.

It’s hard to know for sure if you have foundation problems based on cracks and gaps alone. That’s why it’s always a good idea to get the help of a professional when you aren’t sure about the cause.

Sticking Doors

Do you have a hard time shutting the doors in your home? If your slab foundation has moved, it can change the angle of your door frames, making doors stick to or grind against frames as you open or close them. This tends to be especially problematic in hot and humid weather, but it can happen any time of year with significant foundation movements.

Doors that swing open or closed on their own can also indicate a foundation problem. These issues can make one side of your house slightly higher than the other, which allows gravity to open or shut your doors depending on where they are located in your home.

Uneven or Cracked Floors

It can be helpful to conduct this test throughout the room and other areas in the house if possible. You can also use a bubble level or laser level to see whether your floor is uneven. If your floor is only uneven by a few degrees, it can still mean the foundation has shifted.

Floors made of concrete, tile, or stone can also crack due to shifts in foundation pressure. Keep an eye out for cracks on your floor’s hard surfaces if you suspect your slab foundation has moved.

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Ted Dryce

SEO Content Specialist

Ted is an SEO Content Writer who has been with Groundworks since 2021. He’s covered home repair topics ranging from crawl space encapsulation to regional soil conditions. When he’s not working, Ted is performing improv comedy and working on his own creative projects.