How to Fix Cracks in Garage Floors

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Garage floor cracks are pretty common, especially if you don’t have a basement or deeper foundation under your garage. Despite your best efforts to lay out the garage flooring, you’ll eventually end up with a few cracks.

However, filling large cracks in garage floor concrete is relatively easy as well. Therefore, we’re going to walk you through how to fix cracks in garage floors most simply, as you should be able to handle the cracks yourself and repair the damage.

Sometimes, you’ll have to rely on professional help to fix cracks in your garage floor.

how to fix cracks in garage floor

Regardless of the crack’s size, you should start fixing it as soon as possible rather than ignore it and let dirt collect inside the crack. Moreover, it’s not all that hard to repair the crack, so, there’s no reason you shouldn’t do it almost immediately.

Are Cracks in Garage Floors Normal?

Cracks in garage floors are very common, but not all cracks are normal. Cracks that form as the result of settling or shifting soil can be easily repaired.

However, if your garage floor is cracking due to water damage, you need to take immediate action to prevent further damage and costly repairs.

Cracks Due to Structural Issues – 3 Signs to Look Out For

The signs of cracks from structural issues include:

  1. If the crack on your garage floor bulges out, you can chalk it up to your foundation shifting or contracting a bit, thereby pushing up the bulging area and creating a crack.
  2. Floor erosion is another structural issue you’ll have to pay attention to when trying to identify the crack type.
  3. If the crack is uneven, the concrete on one side is higher or lower than the other side, indicating that the ground underneath is shifting due to a structural problem.

It can take many years and several season changes for these cracks to go from an eyesore to a dangerous structural problem.

However, you should always try and hire a professional to sort things out. As it’s not urgent, you can look around and hire the best contractor you can find for the job.

If you want to make sure the crack isn’t getting worse, you can take some pictures over a few months and compare the cracks.

Why Do Garage Floors Crack?

Garage floors crack because they’re not made from ductile material. Therefore, with weather and temperature changes, the material in your garage floor will not bend or stretch without breaking first. Thus, when the material shrinks or expands, it ends up cracking.

Apart from contraction and expansion, garage floors crack due to pressure from the settling earth underneath or curing issues with the floor.

Cracks in a garage floor are often caused by moisture damage. If the concrete wasn’t properly prepared before it was poured, or if water leaks into the foundation while it’s still wet, the material can start to break down. In addition to causing cracks, water damage can also lead to other problems like mold and mildew growth.

Another common cause of cracks in garage floors is poor drainage around the foundation. Standing water near your garage door can lead to moisture buildup and soft spots underneath the concrete. This may also weaken the material over time, causing it to break down and crack.

However, these cases are rare, and usually, cracks on your floor are cosmetic rather than a result of a significant structural problem with your garage floor. And so, often, you’ll be able to get away with a DIY fix for your garage floor.

How to Fix Cracks in Garage Floors – DIY Steps to Fill Large Cracks in a Concrete Garage Floor

If you decide to handle the crack yourself, and it’s not bad enough that you need to hire professionals, here’s what you need to do to fix the cracks in your garage floor –

Step 1 – Clean the crack and the area around it. You have to remove any dust or debris in the crack without fail. You can use a heavy-duty vacuum cleaner along with a wire brush to get rid of all the debris.  

The goal here is to remove everything cracking and loose and start fixing the crack on a sturdy foundation. And so, this step is how you fix cracks in the garage floor before applying epoxy or other fillings.

Step 2 – Next up is filling up the crack. Here, if you’re dealing with a small crack, you can rely on a self-mixing filler. However, if the crack is substantial, you should instead mix the filler yourself and use it to fill the crack.

Here, you’ll need to pay attention to your local climate and choose a filler mix accordingly. Depending on the type of filler you choose, you’ll have to carefully read the application process before you start to make sure you fill the crack up correctly.

If you want an instant epoxy fix, you can use Gorilla Epoxy for filing small garage cracks.

Step 3 – Ensure you allow enough time for the filler to dry and cure. Usually, you’ll have to expose the filter to special UV lights or sunlight, depending on the mix you use.

Repairing Garage Floor Cracks – Frequently Asked Questions

1.      Should you replace your garage floor or opt for a repair?

If you’re dealing with a significant structural problem on your garage floor, you should opt for a complete floor replacement through professional help.

2.      How should you deal with cracks due to structural issues?

There are cosmetics cracks that you can deal with on your own. And then, some cracks appear due to structural issues. In the case of structural problems, you’ll have to hire professionals to survey your garage and find the root cause of the crack, as they’re indicative of something much worse.

3.      What are the cracks that pop up in the garage floor within the first few months of a new home?

The cracks that appear include –u003cbr/u003eu003cbr/u003ea. u003cstrongu003eShrinkage cracksu003c/strongu003eu003cbr/u003eb. u003cstrongu003eCracks from the home settlingu003c/strongu003eu003cbr/u003ec. u003cstrongu003eCracks during constructionu003c/strongu003eu003cbr/u003ed. u003cstrongu003eCrazing cracksu003c/strongu003eu003cbr/u003ee. u003cstrongu003eCracks due to poor compaction of the sub-gradeu003c/strongu003e

4.      How do you prevent cracks from appearing on the garage floor?

To prevent cracks in your garage floor –

a. Add rebar reinforcement
2. Use post-tension slabs
3. Use a wire mesh for reinforcement

A concrete slab without reinforcement will almost definitely crack. Therefore, your best bet towards preventing cracks is to add support to the concrete slabs.


Fixing the crack in your garage floor is as simple as getting a filler mix, applying it, smoothing it out, and allowing it to cure. Therefore, if there isn’t an underlying structural issue in your home, you should be able to fix a crack on your own.

However, if you pick up on one of the signs there is a deeper structural issue, go ahead and call-in professional help.

Hi, I am Brent Hartman. I am a DIY enthusiast and love to improve and organize the garage in the most innovative way. I created this website out of my passion for helping people organize their garages.

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