“Cracks come to the job along with the concrete, riding in the same truck!”

It’s the keeper of your goods, your memory storage centre of the home, your vehicle’s haven, and your “indoor-outside”. Your garage has been through a lot, but it has never let you down, so why would you let it’s surface deteriorate. Concrete as a garage floor can be one of the strongest, most durable and long lasting materials you can use. But like anything made of concrete, including sidewalks and the rest of your foundation “Cracks come to the job along with the concrete, riding in the same truck”, and are going to happen, but that doesn’t mean you need to just leave them. You’ve got a cracked concrete garage floor, so let’s figure out how to fix it.

Evaluating the Crack in Your Garage Floor

The beginning step to concrete crack repair is as simple as evaluating the crack and determining what caused it. There’s no need to cut out the whole slab for replacement when a simple repair can take place, but you do need to have the know-how to make that call and opt for concrete crack filler.

3 types of cracks in concrete floors and slabs

There are many reasons why a garage floor may crack. There are multiple aspects to consider when evaluating the conditions that may have caused your crack. Crack forms, environmental and soil conditions, building history and movement patterns are only a few circumstances that may have been the cause, but by gauging these conditions relative to the crack it will assist in recognizing the type of crack you’re dealing with and the best way to tend to it.

  • Shrinkage cracks in a slab
  • Settlement cracks in a slab
  • Frost heaves or expansive soil damage

Steps to take in evaluating the crack

After you’ve diagnosed the crack type, there are several, smaller additional steps to take in determining the extent of the repairs to be done. These include but are not limited to:

  • The impact on the surrounding foundation
  • Whether or not the crack is cosmetic or structural (a structural crack is identified by two characteristics, an opening of 1/8 inch or more across, or the crack is “differential” meaning that one side of the crack raises above the other)
  • The probable cause (environmental conditions, or other circumstances as listed above)
  • And the amount of resources (time and money) you’re willing to put towards the concrete crack repair

Fixing concrete floor cracks

Once you’ve identified the crack, and evaluated the impacts, environment, and appropriate repair method, now you can begin the fix.

It is wisest to stick to an epoxy or polyurethane crack repair solution. Choosing a product that is sandable will allow your filler to harden and cure to become stronger than the concrete itself. This will help prevent water intrusion, and will allow you to paint or sand the material with the concrete.

Now it’s time to prepare the crack for the filler. By using a hammer and cold chisel you “chase the crack” by following it in length and breaking away any loose edges or access material. This will allow for the filler to adhere to the materials more effectively, and help rule out the chance of trapped air in the crack. After applying your epoxy or polyurethane filler into the crack, give it a few minutes to settle and allow for low spots to set in. At this point your crack may require a second visit from the filler for any areas that aren’t filled in level. Now you can apply sand to the top and allow the filler to cure and harden for about 20 mins. At this point you can begin scraping away any access from the top layer with a paint scraper or putty knife.


Cracks in your concrete are common and inevitable, and there are various resources for fixing concrete floor cracks and multiple variables to consider before attempting this fix yourself. As in any construction or home maintenance case, it’s important to consider your own abilities and when it is worth it to hire a professional concrete contractor to attend to your concrete repair. If properly handled, these repairs could potentially last for the lifetime of the garage floor.