Cracks in Your Garage Floor? Here’s What to Do

By Sarah Etler - 3/15/23, 9:26 AM
Garage floor with large cracks running across

While it can be very intimidating to notice that your garage floor has developed cracks, it’s actually a very common problem that many homeowners deal with.

At the first sight of cracking, you may be concerned about foundation movement or a serious underlying problem, but a lot of the time, the cracks that form are harmless, even if they do seem scary on the surface.

Here at A-1 Concrete Leveling, we’ve been repairing and preserving our customers’ garage floors for over 30 years, and in this time we’ve gotten familiar with garage floor cracks and how to fix them.

In this article, we’ll walk you through why garage floors crack, how to determine if they’re serious, ways you can prevent them from happening in the first place, and the repair options available to you if you find yourself with garage floor cracks.

Why Garage Floors Crack

Garage floors usually crack due to the following reasons: a lack of proper joints, and the sub-surface shifting which causes the floor slabs to settle or move.

Inadequate Joints

Concrete expands and contracts with fluctuations in temperature, but if there’s no room for this movement, the concrete can crack. 

The intentionally-placed gaps and lines running through your concrete are special joints that allow the concrete to move properly and minimize cracking (expansion joints), or the appearance of cracks if they form (control joints). 

If your garage floor does not have expansion and control joints, there aren’t enough of them, or they’re improperly placed, your garage floor is likely to crack over time due to natural expansion and contraction.


Over time, the slabs that make up your garage floor can begin to sink and become unlevel. During this process, the movement can cause your garage floor to develop cracks.

Settling is caused by many different factors, like soil erosion, improper compaction of the base materials when the concrete was installed, voids under the slabs, and poor water drainage. 

The issues that come with settling can be alleviated by using concrete leveling to fill voids and lift the slabs back up to a level position. Doing this as soon as possible after noticing the slabs are settling can help prevent cracks from forming.

Determining if the Garage Floor Cracks Are Serious

No one wants to find cracks in their garage floor, but if you do, it’s important to determine whether or not they will get worse so that you can repair them before they do.

If you’ve found minor hairline cracks in your garage floor, chances are they aren’t a huge problem. As long as they’re not exposed to any water, they likely won’t widen or worsen.

However, if you notice that a crack is getting wider, you should caulk it. It may be getting wider due to expansion and contraction causing the two opposing concrete pieces to rub against each other. It may also be worsening due to settling.

Monitoring the cracks regularly for any movement or additional damage will tell you if they’re serious and require attention. Seeking the help of a professional can also be helpful in determining why the cracks have formed and what you can do to prevent them from worsening.

Repairing Garage Floor Cracks

Concrete garage floors are different from the standard concrete you find in outdoor driveways, sidewalks, patios, etc. Because garage floors are not usually exposed to water, they have different repair needs than their exterior counterparts.

Garage floors also have a smooth finish, and getting the crack repair to match is difficult for this reason. To repair your garage floor cracks, you will need to decide between using an epoxy material or polymer concrete caulk.

Consulting an expert is the best way to find out which repair method makes the most sense for your particular garage floor cracks.


Using an epoxy crack filler on your garage floor is a sandable option that can help reinforce the crack rather than only seal it up. There are some DIY epoxy products available, but the best option when using epoxy to fix garage cracks is to get it done professionally.

Filling garage floor cracks with epoxy can be labor-intensive and requires specialized equipment to do properly. Prepping the breaks by widening and cleaning them, along with filling any weeping points before the application, is necessary for good adhesion. In addition, a good finished product relies on knowing when to properly shave down the excess epoxy.

Professionals will have access to construction-quality epoxy, plus the tools and know-how to get the garage floor cracks sealed up right.

Concrete Caulk

If you’re not worried as much about strength and would rather just make sure the cracks are sealed up, applying a regular polymer concrete caulk will do the trick.

It’s important to keep in mind that this alternative is not sandable and paint might not stick to its surface, so if you plan on painting over your garage floor in the future, epoxy might be a better choice.

Preventing Garage Floor Cracking in the First Place

The best way to deal with garage floor cracks is to prevent them from happening at all. 

If you are planning on building a new home or adding an additional garage to your existing house, ensuring that the garage floor is installed with the proper control and expansion joints is crucial.

This will allow for proper movement between the floor slabs with the expansion joints and will coax the cracking into the hidden valleys of the control joints.

It’s also crucial to repair sinking slabs at the first sign of settling. If you wait until they have settled too far, the slabs will likely crack before you can get them lifted into the proper place.

Your Next Steps

After learning all about garage floor cracks, you’re ready to decide if they need to be repaired, how you can go about it, and what to do to help prevent new cracks from forming in the future.

A-1 Concrete Leveling has worked with countless homeowners across the country to repair their garages and prevent future damage. If you’d like to see what A-1’s concrete repair services can do for your garage, click the link below for a free onsite estimate!

Want to know more about concrete repair and maintenance? Check out some of these related topics from our online resource library called Concrete Academy:


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Matthew Mueller - Mixer
Matthew has been with A-1 Cincinnati since 2020.
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I ran into an issue with my refi and needed foundation inspection before the bank would let me close. You guys called be back late in the afternoon on Friday and were super accommodating getting me set up with an appointment. Andrew Grey stopped out to provide the inspection and letter. His turn over time on that was perfect. He also gave me some rough bids on a few concrete repair jobs that I was interested in. He was very knowledgeable and helpful. I would certainly recommend you guys to anyone who needs some concrete work! Thank you!

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A-1 Concrete Leveling, Inc.
(888) 675-3835
388 S. Main St. Suite 402b,
Akron, OH 44311