Why Does Concrete Crack?

Concrete is one of the most durable materials, but it’s not immune to damage. If you’ve ever wondered, “why does concrete crack?”, the answer may be more complicated than expected.

In this article, we’ll break down the reasons why concrete cracks, how sinking occurs, and what solutions are available to fix and protect your concrete from future issues.

What Causes Concrete Cracks and Sinking?

Damage to concrete structures in, under, or around your home can come from many sources. The causes of concrete cracks and sinking either begin in the soil under your home and other structures on your property or in the climate itself. 

Soil-Based Issues

The soil beneath your home is just as crucial as its foundation—if not more so. Your foundation relies on stable soil for support.

Soil problems often stem from instability and erosion. Poorly compacted soil, a common issue during construction, occurs when excavation disturbs the ground. Even when soil is replaced and compacted, it’s rarely as stable as before. Over time, this soil can shift or settle, creating voids between your home and the ground.

Erosion compounds the issue, especially in areas with heavy rainfall or dry, windy conditions. Poorly compacted soil washes or blows away, leaving concrete structures unsupported, which can cause settlement, cracking, and sinking.

Climate-Based Issues

Climate-based issues can impact your property from below through the soil or above by direct contact with concrete. Key climate factors include excess moisture, extreme dehydration, and frost heave.

In wet or humid climates, soil saturation can fluctuate due to rainfall or naturally marshy conditions, leading to subsidence, where structures sink and crack. In contrast, excessive dehydration shrinks and cracks soil, creating gaps that foundations can settle into.

Frost heave occurs when moisture in the soil freezes and expands, causing bulges in basements or flooring. When the soil later shrinks from dehydration, these bulges can collapse, creating depressions.

Concrete Settlement Issues Problem Signs

Concrete damage often starts small but can escalate quickly into serious concrete settlement issues. Recognizing the early signs can help you address problems like concrete cracks and sinking before they become structural hazards. Here are the key warning signs:

• Gaps Under Concrete Slabs: Gaps around concrete surfaces are a clear indication of soil displacement caused by erosion or washout. This is one of the primary causes of sinking concrete and should not be ignored.

• Visible Soil Displacement: If you notice soil shifting or washing away after heavy rain or strong winds, take action quickly. Soil displacement weakens the support beneath concrete, increasing the risk of sinking and cracking.

• Unevenness and Movement: Concrete that tilts, sinks, or becomes uneven points to underlying soil instability. These movements often lead to cracks, spalling, and crumbling, requiring immediate attention to prevent further damage.

• Spreading Cracks: While minor cracks are common as a home settles, spreading cracks are a red flag. They signal ongoing stress and strain, which could worsen concrete settlement issues over time.

Repairing Cracked, Sinking Concrete

When it comes to repairing cracked sinking concrete, polyurethane foam lifting, like the PolyRenewal system, is the best solution for restoring damaged slabs. Unlike traditional methods, PolyRenewal addresses the causes of sinking concrete while providing long-lasting results.

Here’s why polyurethane foam is the superior choice:

• Quick and Efficient: The foam is injected beneath the concrete, expanding to fill voids and lift the slab back into place within minutes.
• Lightweight and Durable: Unlike heavy mudjacking materials, polyurethane foam won’t add stress to the soil, reducing the risk of further concrete settlement issues.
• Minimally Invasive: The process requires only small injection holes, so there’s no need for disruptive, messy work.
• Water Resistant: Polyurethane foam doesn’t absorb moisture, helping prevent future concrete cracks and sinking caused by erosion or washout.

By lifting and stabilizing the slab, PolyRenewal eliminates cracks and uneven surfaces, providing a smooth, secure solution to damaged concrete while addressing the root problem.

Contact Innovative Basement Authority for Help with Your Concrete 

At Innovative Basement Authority, we specialize in repairing cracked and sinking concrete using advanced solutions like polyurethane foam lifting.

Our team understands the unique challenges caused by concrete settlement issues and offers long-lasting, minimally invasive repairs that restore the safety and appearance of your concrete surfaces. Don’t wait for small cracks or uneven slabs to become bigger problems.

Contact us today to schedule a free inspection and let our experts provide you with a customized solution to keep your home protected and your concrete strong for years to come.

Leah Leitow

Content Writer

Leah is a Content Writer for Groundworks with more than ten years of experience working in the foundation repair industry. Her experience ranges from working with homeowners to find the right solution to training inspectors and staff. In her background as a Michigan journalist, she gained invaluable insight into people's lives throughout our state. Leah lives in metro Detroit with her husband and two sons.

_{Disclaimer: “Concrete leveling” means the process by which cracked, uneven concrete is stabilized, and in many cases lifted, by means of PolyRenewal™ polyurethane foam. Innovative Basement Authority does not guarantee that PolyRenewal™ can make your concrete perfectly level.}