Spalling is the term for concrete that is cracking, flaking, or breaking away from the surface it was poured to protect. It shows up on facades, balconies, parapets, and parking decks alike, and it almost always has the same root cause.

What Causes Concrete Spalling

• Corroding reinforcing steel that expands and pushes the surrounding concrete apart from the inside
• Freeze-thaw cycles that force water trapped in small cracks to expand repeatedly
• Water intrusion through failed sealant, coping, or flashing
• Chloride exposure from de-icing salts tracked in on parking decks and ramps

Why Spalling Spreads If Left Unaddressed

Once rebar starts corroding, the rust byproduct occupies more volume than the original steel. That expansion cracks the concrete cover, which lets in more water and air, which accelerates the corrosion further. Left alone, a small patch of spalling becomes a much larger repair within a few seasons.

How Professional Concrete Restoration Works

• Removing unsound and delaminated concrete back to solid material
• Cleaning and treating exposed reinforcing steel to stop active corrosion
• Patching with a bonding agent and structural repair mortar matched to the original profile
• Applying a protective coating or sealer to slow future water and chloride intrusion

When to Call a Contractor

Any exposed rebar, falling debris, or rapidly widening crack warrants an inspection right away. Smaller cracks and surface staining are worth documenting and addressing at the next scheduled maintenance visit before they become structural.