How to Fix Cracked Concrete Floor in Your Garage

Do you have an unsightly crack that’s taking over your garage?  If you aren’t familiar with concrete repair, then you might think this to be the end of the world.  You imagine hundreds of dollars of repairs and fighting to get a professional in there to fix the damage.



Even for a homeowner with little experience in working with concrete repairs will be able to do this job because the skills required to repair cracks are only moderate in their complexity. Concrete is a temperamental material, but under the right conditions, it can perform with durability and longevity.  There are a few varying factors that cause cracking in concrete like sideways expansion, lack of proper drainage conditions, extreme temperatures, or the settling and shifting of soil beneath the concrete.

The Right Conditions

The general rule for repairing a concrete crack on your own is that you can fix it yourself if the concrete is the same height surrounding both sides of the crack.  If the concrete is uneven on either side of the division, then it could be an indication of an underlying problem that could require an expert to analyze it. Considering the underlying cause of the concrete crack will save you time, effort, and money in the future.  However, the causes behind a crack are not always obvious, but there are a few cases like the roots of a tree displacing the concrete, or the sure signs of standing water in the area of the crack that will certainly freeze and contribute to the concrete’s breakage. You don’t want to be out in your garage a month or so later doing the same job once again.

Getting Started

Your first step will be cleaning the area in question before you make any actual repairs.  Sweep the garage to see the layout of the crack, and it is even advisable to get out your power-washer and hose off the area, squeegeeing away any excess moisture. You might want to have your shop vacuum nearby to clear away any of the smaller pieces of concrete later when you get to work on the crack. Your garage floor may be stained with the typical substances common to spilling on garage floors like oil and grease.  If this is the case for your garage floor, especially near the area of the crack, then grab some Trisodium Phosphate (TSP), a product that can be purchased at your hardware store, to get out these tough stains. This all may seem like extra work, but your concrete filler will be able to settle nicely with the removal of all contaminates. When it comes to concrete repair, it gets worse before it gets better.  In most situations, you'll have to enlarge the crack before you fill it. This will help you clear out the debris inside of the crack in order to put down fresh filler. Make sure you remove any big chunks of concrete that may have come loose or have broken off, and you should be sure to use a wire brush to sweep away any of the finer particles. Is your cracked concrete on your garage floor deep and wide?  There’s no need to worry because you can actually fix deep and large cracks yourself, too, but it just may take a few extra tools to do the job.  For these types of cracks, use a circular saw fitted with a diamond blade. Make deep grooves on each side of the crack so the filler can be easily added into the channel.  You will have to wear a respirator for safety and have a fan going to control the amount of dust in the garage, pushing it outside.  Use a maul and chisel to work our any other chipped or cracked pieces.

Filling in the Groove

Now that you have thoroughly cleaned and swept up the area free of any remaining debris, dirt, and grime, it's time to put your concrete filler to work.  You should have a fresh surface for the filler to bond successfully. At this point, you'll want to buy concrete filler, and if you want your repair job to last, pick up some concrete sealing product as well.  Some people also buy a latex modifier to mix with their concrete filler and together, add both products into the crack. For many concrete filler products, you'll need to cut the application nozzle off of the bottle, then slowly and carefully fill the cracks.  Follow the instructions on the product’s label for proper application and mixing of your concrete filler.  Once you have poured some of the filler into the crack, wait a few minutes for the product to settle.  You might need to add more to ensure you are creating a tight seal. Patience is key at this part of the process.  Whatever filler you are using, regardless of what the concrete product is mixed with, you are going to have to wait for it to cure for a few hours, preferably overnight.  Check the instructions on the labeling on your products for the appropriate dry time.

Applying a Sealant

Concrete is a known absorber of stains and will soak up anything that’s spilled on its surface.  Grease and oil are frequently used inside garages and you'll want to use a concrete sealant to protect your new application from becoming stained by these stubborn substances. You also don't want your new repair to suffer a crack again, and by applying a sealant or resurfacing agent to the new filler can help protect it.  Your garage floor is being exposed to heavyweight from cars and equipment and also high foot traffic, and in combination with shifts in the temperatures can cause cracking. A heavy-duty water-based polyurethane sealant should do the trick in situations such as these, and the best part is that this product dries quickly so you can add multiple coats for effectiveness. If your garage floor is rough, apply your sealant with a broom or anything with substantial bristles to really work the sealant into the surface’s grooves and pockets. Then, smooth the sealant with a roller or a squeegee.  Your second coat of sealant, depending on what the instructions tell you, can probably be applied within a few hours.  If your crack is in an area that's prone to a high volume of traffic, you might want to consider applying three or even four coats of sealant.

Repairing a Cracked Concrete Floor

Most of the times, those smaller cracks in your garage floor can be easily repaired.  For bigger cracks, yes, you can repair them, but you might want to do a little investigating as to why they occurred initially.  Ask yourself if your garage has any previous drainage problems and check into this issue after a good rainstorm. If you have any concern about the underlying causes of your garage floor cracks, then you should consult a professional.  A consultation will be worth the small expense in order to solve the root issue of the cracking.  As for the actual repairs of the concrete cracks, it can be as easy as adding in a little concrete filler and applying some sealant. At Danley's, your new detached garage will be built from the ground up.  Our professionals handle concrete, construction, and electricity.  With plenty of styles and options to choose from, speak with a specialist and get a free quote today.  Since 1959, we’ve constructed over 100,000 detached garages and we’ve always delivered on quality no matter how big the project is.