Concrete is strong and long-lasting, but even the best slabs eventually crack. Whether it’s your driveway, sidewalk, patio, or foundation, cracks can be unsightly and may even signal deeper structural problems. So, how do you know when it’s time to repair or replace?
This guide will help you understand the types of cracks, their causes, and how to determine whether to repair or replace them completely.
Why Concrete Cracks
Cracks form for several reasons, and knowing the cause can help you choose the right solution. One of the most common reasons is shrinkage during the curing and drying process. As concrete loses moisture, it naturally contracts, which can cause minor surface cracks.
Temperature swings can also cause expansion and contraction. In areas like New York, where the weather changes fast, this stress builds up and often leads to cracking. Heavy vehicles or dropped objects can cause impact damage. Poor installation and missing control joints also play a role. Sometimes the ground underneath moves or settles, leading the slab to shift and crack.
Not all cracks are serious, but they can grow worse if ignored. Some are just cosmetic, while others hint at serious structural concerns.
Different Types of Concrete Cracks
Small cracks that are less than 1/16 inch wide usually appear as hairline fractures. These typically happen because of shrinkage or temperature shifts. They don’t pose much risk and can often be sealed or filled to restore the surface.
Some cracks only affect the top layer of the concrete. These surface cracks might appear in a web-like pattern, often referred to as “crazing.” While they don’t weaken the slab, they can make it look worn. A resurfacing treatment usually takes care of this issue.
Vertical or diagonal cracks, especially in walls or foundations, often suggest a settling issue. Depending on how deep they are or whether they continue to grow, you may need a full replacement.
When slabs start to lift, become uneven, or heave, the problem usually comes from tree roots, frost, or soil movement underneath. These cracks become trip hazards and usually require the entire slab to be replaced.
If you notice cracks that keep widening, especially if they let in water, that’s often a warning sign. These might indicate deeper structural failure and are usually better solved with replacement rather than repair.

When It’s Better to Repair
You can repair cracks that are narrow and stable. If the concrete hasn’t shifted up or down and the structure remains strong, a repair will often fix the problem. This approach also makes sense if you want a quicker, more affordable solution.
Typical repair methods include using caulking or epoxy to fill small cracks. For worn surfaces, professionals can resurface the slab with a fresh layer of concrete. If part of the slab has sunk slightly, a technique called mudjacking or slabjacking can lift it back into place. Overlays are also an option when you want to refresh the appearance without starting from scratch.
You’ll usually get good results from repair work if you’re dealing with a light crack in your driveway, a few flaws on your patio, or minor foundation issues that aren’t causing leaks or instability.
When You Should Replace the Concrete
If your cracks are wide, deep, or getting worse, it’s often best to replace the concrete. The same goes for situations where one side of the crack is higher than the other, making the surface uneven. Sinking or shifting slabs also call for replacement, especially if the base beneath the concrete has failed.
Concrete that has already been repaired several times may no longer hold up well. In that case, a full replacement ensures you won’t face constant patch jobs or worsening problems.
Driveways or walkways with large missing chunks or major cracks usually can’t be saved with repair methods. If you see that kind of damage on your patio or pool deck, replacement gives you a better long-term result. And when it comes to foundation damage, you should always speak to a concrete expert first. Structural problems require careful assessment and, in many cases, a full replacement.
How to Prevent Cracks in the Future
While no concrete is fully crack-proof, you can lower the chances with the right preparation and care. Always make sure your contractor uses control joints to manage where cracks form. The soil underneath should be compacted and graded properly to avoid settling.
Sealing the surface regularly keeps water out and protects against freeze-thaw cycles. Adding steel reinforcement like rebar or mesh improves strength. Avoid placing heavy loads on unsupported areas, especially near edges.
Still Not Sure? Ask a Professional
If you’re looking at cracks in your concrete and don’t know what to do next, it’s best to get a professional opinion. A trained eye can quickly tell whether a repair will do or if you need something more.
At NYPaver, we help New York homeowners assess their concrete surfaces and find the right fix. Whether you need a fast repair or a full slab replacement, we’ll make sure your property stays safe, strong, and great-looking.
Call now for a free on-site evaluation or book online to get started.