Fixing Spalled Concrete: How to Save Your Crumbling Steps

It looks like a skin disease for your concrete. The smooth top surface starts to pop off in little flakes. Then the flakes become pits. Before long, your driveway or front steps look like the surface of the moon—rough, rocky, and ugly.

This is called spalling (or scaling). It is one of the most common concrete issues in Charlotte, and it drives homeowners crazy. It makes a relatively new driveway look 50 years old.

The good news? You don't have to live with it, and you don't have to replace the concrete. Spalling is almost always a surface issue, not a structural one. We can resurface spalled concrete to look brand new, providing a durable "wear layer" that is actually stronger than the original surface.

Why Does Concrete Spall? (The Science)

Concrete is like a sponge; it absorbs water. In Charlotte, we have a freeze-thaw cycle in the winter. Water soaks into the top layer of your driveway during the day. At night, it freezes. When water freezes, it expands by 9%. This expansion creates microscopic pressure inside the concrete pore.

Eventually, the pressure pops the top layer of concrete off, just like the cap off a bottle.

The Salt Factor: Using rock salt (sodium chloride) on your concrete accelerates this process 10x. Salt attracts water and lowers the freezing point, causing the water to freeze and thaw dozens of times in a single night. It also chemically attacks the "glue" in the cement paste.

The Fix: Polymer-Modified Resurfacing

You cannot just patch spalling with regular cement from Home Depot. Standard concrete cannot be poured thin (less than 2 inches); it will crack and flake off immediately because it doesn't bond well to old concrete.

We use Polymer-Modified Concrete Overlays. These are high-tech cement mixes fortified with latex or acrylic polymers. The polymers do two critical things:

1. Chemical Bonding: They act like superglue, allowing the new layer to stick permanently to the old slab.
2. Flexibility: They allow the thin layer to expand and contract with the temperature without cracking.

Our Resurfacing Process

Step 1: Aggressive Prep. We use a 3,000 PSI pressure washer with a turbo nozzle (or sometimes a concrete grinder) to blast away all loose, weak concrete. We want a clean, rough surface.

Step 2: Slurry Coat. We scrub a liquid bonding agent into the pores of the old concrete. This ensures the new layer grabs on tight.

Step 3: The Overlay. We trowel down the polymer cement mixture. Depending on the depth of the spalling, this might be 1/4 inch to 1/2 inch thick. We feather the edges so it transitions smoothly to your garage floor or sidewalk.

Step 4: Texturing. While the material is wet, we apply a broom finish. This is critical. Smooth concrete is dangerous when wet. The broom finish provides the non-slip traction you need for a driveway or steps.

Step 5: Sealing. Once cured (usually 24 hours), we apply a penetrating siloxane sealer. This waterproofs the new surface, preventing water from soaking in and starting the freeze-thaw cycle all over again.

Prevention: How to Protect Your New Surface

Once we restore your concrete, you want to keep it that way.

• NEVER use Rock Salt. Use magnesium chloride or calcium chloride de-icers instead, or just use sand for traction.
• Seal it every 3 years. A good penetrating sealer keeps the water out.
• Keep it clean. Wash off road slush (which contains salt) from your car and driveway promptly.

Conclusion

Spalled concrete makes your home look neglected, but underneath that rough skin is usually a healthy slab. Don't pay $10,000 to replace a driveway just because the top 1/8th inch is flaky. Let Charlotte Concrete Repair resurface it for a fraction of the cost. We give you a brand new, salt-resistant "wear layer" that looks great and lasts for decades.