A Homeowner’s Guide to the Common Types of Cracks in Concrete

Has that crack always been there? Are you looking at a new crack in your home’s concrete foundation? Sometimes it seems like every concrete surface has at least one crack, and it’s easy to overlook or ignore it. 

Concrete is strong, right? It’s one of the most common building materials because it can withstand a crack without leading to a significant structural problem in most buildings. However, sometimes a concrete crack is more than a small cosmetic issue.

How can you tell if a crack indicates a severe problem? Keep reading to learn more about the types of cracks in concrete and when to fix them.

Hairline Cracks

Hairline cracks are difficult to see due to their small size and the thin gap in the otherwise smooth surface of your concrete. Since they aren’t big and don’t look dangerous, it’s easy to dismiss these cracks as a non-issue. However, while hairline cracks won’t often affect the stability of a building’s foundation, they can allow water to seep in and create water leakage issues.

They’re one of the most common concrete cracks and typically develop as concrete cures. If the concrete mixing happened too quickly, you’ll see hairline cracks start to form shortly after it cures. 

Don’t ignore these small breaks in your foundation. Fill the cracks with a patch kit before they grow into a more significant issue.

Temperature Shrinkage and Expansion Cracks

Concrete expands in the heat and contracts in low temperatures. If your home is in an area with high and low temperatures, your foundation and patio concrete areas continuously expand and shrink as the temperatures change.

While you won’t see your foundation grow larger or become smaller, you might see the effects of shrinkage and expansion as horizontal, jagged cracks in the concrete’s surface. When these cracks appear, pay attention. The more your foundation or patio adjusts to changing temperatures, the current cracks can get bigger, and additional cracks can form. 

Shrinkage and expansion cracks need immediate attention. They’ll continue to grow and damage more extensive areas of concrete. A professional foundation repair company can insert expansion joints and other repairs to minimize the structural impact of large concrete cracks. 

Plastic Shrinkage Cracks

While concrete is still in its plastic stage before full hardening, it contains water. As the water evaporates, it leaves behind hardened spaces that can collapse. This collapse sometimes causes stress on the surface, and cracks form before the concrete cures completely. 

You’ll find these cracks around posts and corners in your concrete slab. They can be hard to notice on the surface, but they aren’t confined to the surface. If you see them, chances are there are more plastic shrinkage cracks throughout the slab underneath the surface. 

Using the appropriate amount of water in the concrete mix helps prevent plastic shrinkage cracks. If you see too many cracks, the mixture was too wet to cure correctly. However, in most cases, these cracks won’t affect the structural integrity of your concrete. 

Settling Cracks

The concrete mix or curing isn’t the leading cause of settling cracks. This type of crack appears when the underlying ground and support surrounding the concrete slab becomes unstable or shifts. 

When the ground shifts, this activity creates a void around the concrete slab. This creates space and opportunity for the concrete to buckle under the unexpected stress of space. When the concrete shifts, a crack forms. 

Settlement cracks usually appear as deep cracks that travel downward. In severe cases, the crack can separate into an offset gap or lip, creating a hazard in a sidewalk or along the edge of a building. 

Not all settlement cracks are severe. However, these cracks are symptoms of foundation shifts that can also cause doorways to shift and floors to slope. If you see these cracks and struggle to close doors in your home, it might be time for foundation repair. 

Premature Drying Cracks

Did you know that concrete could be so temperamental? If the mix is too wet, you get the plastic shrinkage cracks we mentioned. If the mixture loses moisture too quickly, this can also lead to premature drying cracks. 

These are small, spider-web-like cracks that don’t often cause significant damage. However, if you hoped for a pristine concrete surface with no cracks, these tiny cracks can ruin that effect for you. 

Cracks Caused By Overloading

Concrete is strong and can handle plenty of weight, but even the best-laid slabs can crack under too much pressure. Laying a concrete foundation or patio slab requires more than filling a hole that’s the right size to support the plans for a house. A successful concrete pour and cure requires an accurate mixture, depth, dimension, and structural support for success.

Builders also have to factor in the weight of the materials required to build the structure on top of the cured concrete slab. Too much weight can cause stress cracks in the foundation as the pressure increases on the ground beneath the slab. As the ground shifts to handle the concrete slab’s weight and the building’s structure, the concrete cracks. 

If you’re building a patio or other type of structure, pay attention to your concrete mixture’s PSI strength to avoid an overload problem later. 

Can You Minimize Cracks?

Concrete is one of the most common materials for building and patio construction, and it’s possible to minimize the potential for cracks. A good mixture and the right curing conditions help prevent gaps in a slab. Choosing an option like a stamped concrete patio gives you an affordable and unique flooring option that’s less likely to show cracks. 

Watch For These Types of Cracks In Concrete

Not all concrete cracks require repair, but it’s a smart idea to keep an eye on these types of cracks in concrete. Whether you learn to live with them or repair cracks before they can cause significant issues, knowing what to look for can help protect your home. 

We hope you found this information helpful! Be sure to browse more of our informative articles.