Concrete slabs are a great foundation for garages: they can bear a lot of weight and provide a flat surface that’s great for parking. However, garage floors can crack, which might lead you to wonder when you should be concerned about the foundation under your garage—or the rest of your home. Concrete floor crack are common, but some cracks suggest bigger problems than others.

Causes of Concrete Slab Cracks

Concrete can crack, leading it to become uneven. What causes foundations to become uneven in almost all cases is water. No matter how well your home is built, the presence or absence of water will end up affecting your foundation eventually. Too much water from heavy rainfall or melting snow can lead to saturated soil that puts pressure on your home’s foundation, and too little water can cause the soil to shrink and become unable to support the foundation. Water problems can lead to upheaval or settlement, which are common causes of cracks in garage floors.

What Do My Cracks Mean?

Some cracks are more cause for concern than others. In general, if there are a large number of cracks, the cracks are wider than 1/16 of an inch, or a crack has one side that’s higher than the other, it’s worth checking for soil and foundation movement. Cracks that run across your garage floor and continue up the garage wall could also be a sign of problems. Keep an eye out for these cracks and the concrete slab foundation problems they could indicate.

Cold joints look like cracks but pose no threat to your home’s structure. A contractor put them in when the concrete was poured. After one section of concrete is poured and hardened, another section is poured next to it. Control joints are also placed by contractors: cracking concrete is inevitable, but control joints in slabs make it possible to control where the cracks happen to an extent. Cracks along control joints will be straight lines.

Hairline cracks are thin but could be deeper than they look. Concrete settling while it cures generally causes them. If they’re deep, they can lead to wider cracks over time.

Plastic shrinkage happens when concrete is cured incorrectly. These cracks are short, random, and reach about halfway through the concrete. This is normal and generally not anything to worry about.

Settlement cracks are common in new and aging garages as a result of pressure put on the floor. If they get wide enough and continue to grow, they can lead to bigger problems. Look for them underneath where your tires rest and in the corners of the garage.

Crazing is a result of uneven drying while concrete cures. It leads to shallower hairline cracks in random or hexagonal patterns, and the damage is generally not serious.

Scaling is the result of concrete and air pockets near its surface absorbing water and expanding when temperatures drop, which can cause blisters and potentially cracks the slab foundation.

Spalling is a deeper crack caused by rusting and deteriorating rebar inside concrete that can potentially lead to exposed metal.

Offset cracking causes differences in the height of concrete on either side of the crack and is generally caused by a slab sitting on the ground unevenly.

How to Repair Concrete Slab Foundation Problems

The best methods for repairing cracks in garage floors involve keeping moisture from getting into the crack and widening it. Epoxy or polyurethane resin injections are common and good for keeping out water. Another option for home repair of small cracks involves mixing patch powder with latex and applying it to cracks. Some cracks require more than a DIY home repair, though, which is when homeowners benefit from calling in a foundation expert.

Acculevel has a few options for concrete slab foundation problems. Slab jacking can be used to lift concrete into its original position through an injection of stabilizing foam material under the slab. This material is safe, effective, and more refined and cleaner than other techniques like mudjacking. A foundation repair expert can also help you assess other areas in your home that might have become damaged as a result of foundation problems.

Concrete Slab Foundation Problems Solved by Acculevel

Midwestern homeowners face a lot of foundation challenges that need to be addressed before they cause serious damage. Your garage floor isn’t the only thing that gets impacted by foundation issues: it’s better to address problems as soon as possible to make sure that your entire home is stable and in good repair for years to come. Acculevel can do a variety of concrete slab and basement foundation repairs based on what problems you’re experiencing and what works best for your home. For a free home inspection, contact us today.