How Do I Fix Cracks On a Concrete Garage Floor?

Concrete garage floors are prone to cracks. The good news is that you can fix cracks on a concrete garage floor without any complex tools and materials. It is important to identify the cracks as early as possible and fix them before they get worse. The deeper the cracks, the more difficult it becomes to fix them. Cracks in the concrete floor can be dangerous because they can make the floor to start sinking. These cracks can also accumulate moisture and cause mold in the garage.

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How to fix cracks on a concrete garage floor

1. Start by Identifying the cause of the cracks

The first step is to identify the cause of cracks. Concrete garage floor cracks are common and sometimes normal. Since cracks are likely to happen at some point, identifying the cause of the cracks can help you to deal with the issue and avoid further damage. Here are some causes of cracks on concrete garage floors:

Natural shrinkage after installation

It is not uncommon to see shrinkage after concrete installation. If you installed concrete flooring in the last few months or weeks, it is normal to notice some cracks. These cracks occur because of the natural shrinking process of concrete. Cracks that are caused by natural shrinkage are nothing to worry about, and they can be easily fixed. These cracks are not dangerous, and they cannot affect the integrity of the building.

concrete cracks small

Settlement cracks

Apart from shrinkage cracks, we also have settlement cracks. These are cracks that happen due to the natural movement of the soil. The soil under your garage will move over the years, and it is normal to see some cracks on the concrete floor. Compared to shrinkage cracks, settlement cracks are a bit serious. However, with a good repair technique, it is easy to fix them. You can fix these cracks by using concrete sealers before they become worse.

Poorly installed floor

If your concrete floor was not properly installed, you are likely to see cracks. The cracks might happen because of using the wrong mixing ratio. This is why it is advisable to get the services of a professional when it comes to garage floor installation. In extreme cases, fixing the cracks might not solve the problem; you might be required to get a new garage floor altogether.

Flooding and water damage

Sometimes cracks on your concrete floor can be caused by garage flooding and water damage. Stagnant water on your concrete floor will start penetrating the floor and cause damage. It is advisable to think about garage drainage and avoid water flooding in the garage. Keeping the garage floor dry can be helpful in preventing cracks.

2. Inspect the crack

The first step should be an inspection of the crack. Inspecting the crack is a good way to know the course of action. You need to inspect the crack to determine how wide it is and also the location of the crack. Sometimes the cracks are too big for DIY, and you might be required to get the services of a professional. However, small cracks are easy to repair and do not need much work.

3. Clean the concrete crack

Cleaning the crack is always a good idea before you do any work. It is important to clean the crack so that you can remove any debris and dust particles. Cleaning the space will also give you an idea of the size of the crack. Sometimes the crack is always bigger than how it looks because of the accumulation of dust particles.

Proper cleaning will also allow the concrete filler to last on the crack. The best way to clean up a concrete crack is by using a wire brush. A stiff wire brush will go to all the parts of the crack removing sand and concrete particles. You can also use a leaf blower to blow away all the particles that will be left on the crack.

Repairing small garage floor concrete cracks

Repairing small garage floor concrete cracks is the easiest. You do not need to hire any professional to help you. It is possible to seal the cracks using some of the readily available materials on the market. Using a garage floor concrete filler tube is the easiest way to small cracks. For cracks that are less than 0.5 inches wide, using a tube concrete filler is the best.

Items required

  • Crack filler tube – DAP 37584 Crack Filler
  • Wire brush for cleaning


  • Clean the crack to remove all the debris with a wire brush
  • Inject the concrete crack filler tube to fill up the crack.
  • Level up the area to get rid of the excess filler

Advantages of using DAP 37584 Tube Crack Filler

  • Comes already mixed and helps you to save time
  • Dries up fast – you can use the space in less than an hour.
  • Easy to use and less messy

Repairing medium-sized cracks on a concrete garage floor

Medium-sized garage floor cracks are also easy to repair. You need to get the right type of concrete filler depending on the extent of the crack and also your preference. Using epoxy concrete filler is the best way to fill most of the medium-sized cracks. Epoxy 3 parts concrete filler can be used for cracks that are as big as one inch. This epoxy filler binds well on concrete, and it is as good as concrete.

Items required

  • Epoxy filler three parts – FDC 3 part epoxy patching system
  • Mixing can
  • Wire brush
  • Finishing trowel


  • Mix the three parts of the epoxy patching system together. The three parts contain resin, hardener, and aggregate. You can always check the instruction on the packaging on how to mix the epoxy system. However, make sure that you do not mix for too long.
  • Pour the epoxy system into the cracks. You need to make sure that you fill-up the cracks are well so that you do not leave any spaces.
  • Flatten the areas with a finishing trowel.

Repairing wide cracks on a concrete garage floor

Repairing wide concrete garage floor cracks can be a little tricky. It is important to make sure that the integrity of your garage is still intact before you think about doing concrete cracks repairs. If your garage structural integrity is highly compromised, it will be better to address the problem from the source. However, repairing wide garage floor concrete cracks is still possible.

concrete cracks

Items required

  • Concrete patch –
  • Circular saw
  • Hammer
  • Mixing container
  • Trowels


  • Chisel the concrete crack – the first step should be to chisel the concrete crack. You need to make sure that you chisel the crack with a circular saw to define the crack. It is a good way to know how deep the crack as gone. In case you do not have a circular saw, a hammer will work out just fine to chisel the concrete crack.
  • Clean up the crack – cleaning up the concrete crack is the next step after chiseling the crack. You need to make sure that the space is clean so that the concrete patch can stick. Clean the area with a wire brush and also use a blower.
  • Fill the space – once the crack is clean and dry, use a concrete patch to fill the space. Make sure that you adequately feel the space without any space.
  • Flatten out the concrete – the last step should be to flatten out the concrete with a trowel.
  • Wait for it to dry – you will need to wait at least a day for the concrete to dry up.

When should you replace your garage floor?

Repairing a concrete garage floor is always a viable solution to seal cracks. Small and medium-sized cracks of the garage floor can be easily repaired. However, there are cases when replacing the entire floor is necessary. Here are some instances when you should replace your garage floor:

The garage floor is older than 15 years

If your garage floor is more than 15 years, it is time to consider getting a new one. Replacing your garage floor with a new one is always an idea because old floors can be problematic. The cracks tend to increase over time, and they become difficult to fix.

Significantly big cracks

It is very important to observe cracks and determine to determine the size and the location. Cracks near the walls need more attention, and you might be required to replace the entire floor.

Replace concrete floor with a durable floor

A time comes when you need to replace your concrete floor with more durable flooring. Concrete is usually not the best option for garage flooring. It is always advisable to get better flooring like epoxy of floor tiles.

You can check these garage floor ideas available for your floor.

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