Fixing Large Cracks in Concrete Slab Garage Flooring

While concrete slab garage floors can last far longer and are far more durable than alternatives such as asphalt or concrete pavers, occasional concrete repairs are necessary. Cracks in concrete garage flooring are inevitable but it is always best to take care of cracks immediately before they become large cracks which are more difficult to repair. When large cracks do occur, it is important to fix them correctly to avoid more permanent damage.

What Causes Cracks in Garage Flooring

Cracks are an inevitable part of owning concrete slab flooring and do not always mean it has not been taken care of properly. Concrete has very low ductility so once it is set it cannot expand or contact without cracking. This can occur due to normal temperature fluctuations throughout the year. Properly poured concrete slabs will have contraction joints built into their base to account and minimize cracking. 

In addition to cracks developing as a result of temperature fluctuations, cracks can also occur due to the settling of the earth or other base beneath the slab. Both of these things are factors that are beyond anyone’s control. What can be controlled is how they are repaired when they occur. 

Cracks can be divided into 3 categories:

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

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.

When Does A Small Crack Becomes a Large Crack

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.

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

Executing Concrete Repair on Your Garage Floor

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.

When Should You Bring in a Professional

Cracks in your concrete slab floor are common and inevitable, and there are various resources for fixing concrete floor cracks and multiple variables to consider before attempting this fix yourself. Restore All concrete contractors have many years of experience and will ensure your project is completed professionally, and with the highest degree of quality. Whether you’re looking to add a porch, patio, pool, or precast steps to your backyard, Restore All can help you create the oasis you deserve. Contact us today to talk about your next project.