Garage Floor Repair: Fix Cracks, Pitting, and Oil Stains Without Replacing

Your garage floor is probably the most abused concrete surface in your home. Every day, it endures the weight of 4,000-pound vehicles, oil drips, gasoline spills, road salt dragged in from your tires, and extreme temperature swings from hot summer days to freezing winter nights. Yet most homeowners never think about their garage floor until it becomes an eyesore—or worse, a safety hazard.

If your garage floor is cracked, pitted, stained, or flaking, you might assume you need to jackhammer it out and pour a new one. In most cases, this is completely unnecessary. Garage floor repair and resurfacing can restore your floor to like-new condition—or even better—for a fraction of the replacement cost.

The 4 Most Common Garage Floor Problems

1. Surface Pitting and Spalling

What it looks like: Small pockmarks or larger areas where the surface is flaking off, leaving rough, exposed aggregate.

The Cause: This is almost always freeze-thaw damage accelerated by road salt. Your tires bring in snow mixed with sodium chloride. The salty water soaks into the concrete pores. When temperatures drop at night, the water freezes and expands, popping off the surface layer. This cycle repeats dozens of times each winter.

The Fix: We grind away the loose, damaged surface layer and apply a polymer-modified concrete overlay. This new "wear layer" is denser and more chemical-resistant than the original concrete. We can apply it as thin as 1/8 inch or as thick as 1/2 inch depending on the damage depth.

2. Cracks (Shrinkage and Settlement)

What it looks like: Linear cracks running across the floor, sometimes with one side higher than the other.

The Cause: Garage floors are typically poured directly on the ground after the house is built. The "backfill" around the foundation is often poorly compacted. Over years, this soil settles, leaving voids beneath the slab. The heavy, unsupported concrete eventually cracks.

The Fix: We treat these depending on severity. Hairline cracks get filled with flexible polyurea or epoxy fillers. Settlement cracks (where one side has dropped) require foam lifting first to stabilize the slab, then crack filling. Major structural cracks may require sectional replacement of a portion of the floor.

3. Oil and Chemical Stains

What it looks like: Dark spots or discoloration, often near where you park.

The Cause: Oil, transmission fluid, brake fluid, and gasoline are petroleum-based and soak deep into concrete pores. They don't just sit on the surface; they penetrate.

The Fix: We use industrial degreasers and poultice treatments to draw out as much oil as possible. For stubborn stains, we grind the affected area to remove the contaminated layer. The key is proper prep—if you coat over oil, the coating will peel. Once clean, a high-build epoxy or polyaspartic coating will cover the stain permanently and prevent future penetration.

4. Dusting (Chalky Surface)

What it looks like: A powdery white residue that appears on your shoes, car tires, or anything that touches the floor.

The Cause: "Dusting" occurs when the surface of the concrete was improperly finished or cured. The top layer never fully hardened and is slowly turning back into powder.

The Fix: We apply a penetrating concrete densifier (a chemical that reacts with the cement to harden it), followed by a sealer or coating. This transforms a weak, dusty surface into a hard, cleanable one.

The Coating Options: From Basic to Showroom

Once we've repaired the structural issues, you have choices for the final surface:

DIY vs. Professional: Why Most Home Kits Fail

Home improvement stores sell garage floor epoxy kits for a few hundred dollars. They look appealing. But we repair more failed DIY epoxy jobs than almost any other garage floor problem. Here's why they fail:

• Prep Failure: The kit instructions say "clean the floor." But concrete needs more than mopping. Professional jobs involve diamond grinding or acid etching to open the pores. Without this, epoxy peels off like a sticker.
• Moisture Issues: If your slab doesn't have a vapor barrier beneath it (most older homes don't), moisture pushes up from the ground and lifts the coating. Professionals test for this and use moisture-mitigating primers.
• Thin Coverage: DIY kits spread thin—often 3-5 mils. Professional coatings are 10-20+ mils thick. Thin coatings wear through quickly, especially under car tires.

Cost Comparison

Conclusion

Your garage floor doesn't have to be an embarrassment. Whether it's pitted from salt, cracked from settling, or just dull and stained, professional repair and coating can transform it into a durable, attractive surface you're proud to show off.

At Charlotte Concrete Repair, we specialize in garage floor restoration. We fix the problems first, then protect the surface so those problems don't come back. Stop covering your garage floor with rubber mats and hoping no one notices. Call us for a free assessment.