Concrete slabs for your garage floor are sturdy and can bear a lot of weight – great for parking a car or two. Unfortunately, they will eventually develop cracks. You might not notice the cracks right away, but they will appear over time, some barely noticeable while others are a bit concerning.
Here’s the thing. Cracks on concrete floors are pretty common. But some cracks can cause bigger problems when left alone. If you discover cracks on your garage floor, it’s always smart to know how to tell when to worry and how to fix cracks in the garage floor before they become a serious issue.
Is It Normal to Have Cracks in the Garage Floor? Should I Be Concerned?
No matter how well and carefully made your garage floor is, cracks may start appearing eventually. It’s quite normal, and usually, you don’t have to worry about them. Cracks in the garage floor appear over time for many reasons, and unless they are an indication of serious structural issues, you’re all good.
Still, fixing these cracks is ideal as they aren’t the prettiest to look at. Plus, dust and debris can gather in the cracks, and not to mention slush and ice during winter.
Why Are There Cracks on the Garage Floor?
All concrete floors crack. That is simply the way it is. Two main reasons cause cracks to appear on the garage floor.
- The concrete contracts when the temperature is cold.
- It expands when the temperature is warm.
Continued contraction and expansion whenever the temperature changes then cause cracks in the garage floor.
What Do the Cracks in Garage Floor Mean?
Fixing small cracks on the garage floor is pretty doable. But first things first, you have to understand what those cracks mean. Keep an eye on what those cracks look like, how long they are, and understand what problems they could indicate to repair them correctly.
- Hairline Cracks
These types are thin, like a strand of hair, but they can be deeper cracks than they look. They usually appear because the concrete settles while it’s still curing. Typically, they are not a cause of concern, but if hairline cracks are deep, they can lead to wider cracks over time.
- Cold Joints
These look like cracks but were intentionally placed there when pouring the concrete. It’s one of the types that often get confused with cracks in the garage floor. You might see these cracks/control joints in straight lines.
- Shrinkage Cracks
Shrinkage cracks appear on concrete floors because they cured incorrectly after pouring. You can see these as short and random cracks in the slab. Typically, it’s pretty normal and isn’t a cause of concern.
- Settlement Cracks
These cracks usually appear in both new and aging garages. They are a result of applied pressure on the floor. Look out for them around the corners of your garage or where you park your cars. Settlement cracks are a cause of concern as they can continue to grow and get wide enough over time.
- Crazing Cracks
Crazing cracks happen when the concrete dries unevenly during its curing period. It often leads to shallow hairline cracks that appear in hexagonal or random patterns. They don’t appear very pretty, but the damage is usually not serious.
- Offset Cracking
This cracking happens when the concrete floor sits on the ground unevenly, causing a significant height difference between the two sides of the cracked concrete.
Cracks in the garage floor can be thin and minor. Other times, they can go more than an inch wide and spans the entire length of the garage floor.
Tip: Look out more than just the cracks in the garage floor. If you see some of these signs, it’s a good indication that the cracks relate to more serious foundation issues.
- Are the garage doors and windows inoperable or difficult to open or close?
- Are there cracks in the garage walls or siding?
- Does the crack in your garage floor continue to the walls?
- Does your garage roof sag?
- Is the garage floor sloping?
Note: So long as the cracks are cosmetic, it’s pretty simple to fix. Should the cracks in the garage floor have rust stains, run extended lengths, or getting worse or wider, it’s best to consult a professional.
How to Fix Small Cracks in the Garage Floor?
Alright, so you decided to repair or fix the cracks in your garage floor. Here’s the best way to do it – prepare and clean the cracked area, then fill it. But this only applies to small cracks or cosmetic cracks that aren’t serious but makes your garage floor look bad.
1. Prep the Cracked Garage Floor Area
Fixing small cracks in the garage floor is easy enough, but always start by preparing the area. There may be some dust and dirt inside those cracks, and you want to get rid of them before filling them.
Take the time to vacuum whatever’s stuck in those cracks. You might even consider running a bristle brush in there to make sure you removed any debris or chipped concrete. Pressure washing the cracks and their surrounding area is also smart, but make sure you give it enough time to dry before continuing to the next step.
If you’re dealing with longer cracks, get ab angle grinder with an attached crack chasing masonry wheel. It will help you create a smooth grove, tiny up everything to save you a lot of time.
The main goal for this step is to get rid of anything that shouldn’t be there, including loose or crumbled concrete that may fall off even after you fill the cracks. Making sure that there is no crumbling foundation left will ensure that your repair lasts very long.
2. Fill in the Cracked Garage Floor
For smaller cracks or those not wider than ½-inch, use a self-mixing crack filler. They are easy to use since they won’t require you to mix batches of fillers. Crack fillers are waterproof and will dry in a milky clear color with a concrete-like finish.
A tube of self-mixing crack filler works with a standard caulking gun. Different products will come with their own instructions but applying crack fillers using the caulking gun is pretty straightforward.
- Run a bead of the crack filler down the cracks in your garage floor.
- Work the filler into the cracks using a small trowel and allow it to settle.
- Consider applying additional filler if some areas look a little thin and uneven.
Once done, allow at least 24 hours for the crack filler to completely dry before walking over it or using the treated floor space. If you live in a moist climate, a longer drying time may be necessary.
How to Fix Large Cracks in the Garage Floor?
If your garage floor has larger cracks, anything wider than ½-inch, further steps are necessary to fix them. Fixing large cracks on concrete will also depend on their lengths and depth.
1. Further Prep Large Cracks
Clean the cracks on the garage floor and its surrounding area the same way you’d clean smaller cracks as mentioned above – use a vacuum, bristle brush, and a crack chaser.
In addition, get yourself a cold chisel to undercut the cracks in the garage floor to a minimum depth of 1-inch. Undercutting the cracks will help hold the filler or patch and limit any further damage on your garage floor. Remember to wear proper protective gear during this step.
Once you thoroughly undercut the cracks, clean the area again. Pressure washing may be necessary to take out any dust and chipped concrete from your undercutting, then allow the surface to dry.
2. Fill in the Cracks
For filling bigger cracks, you have two options: an epoxy concrete patch or a polymerized concrete mixture.
An epoxy patch kit usually has two parts: epoxy and sand. You’ll have to mix these two parts on a piece of board, then use the mixture to fill the cracks in your floor.
Note: When using an epoxy patch kit, avoid overmixing the two parts to prevent premature curing before you apply the mixture to the cracks. Mixing in batches or as needed is ideal to avoid having cured mixture that will be unusable later on.
The next option is the polymerized concrete, which is much easier to apply than epoxy. You only need to mix it with water to form a smooth paste you can use to fill the cracks with it – just like any concrete mixture. The downside is it’s not as strong as epoxy, but it dries medium gray, almost the same color as bare concrete. It will closely match your garage floor once it hardens if that’s a priority.
It is normal to see cracks on the garage floor. So, don’t worry if you start seeing a bunch of smaller cracks, whether it’s after the concrete flooring is cured or as it ages. Plus, cracks in the garage floor are easy to rectify.
However, there may be times where larger cracks may appear, and it’s important to check a few other things in the garage to determine the seriousness of the issue.