Spalling Concrete: Causes, Prevention, and Long-Term Repair Solutions

Spalling Concrete: Causes, Prevention, and Long-Term Repair Solutions

Is your concrete driveway, patio, or wall flaking and chipping like old paint?
This unsightly issue is called spalling concrete, and it’s one of the most common forms of surface damage homeowners and property managers face.

In this guide, we’ll explain:

  • What causes concrete spalling
  • How to prevent it
  • Step-by-step methods for repairing spalled concrete
  • How SEMCO's  X-Bond and Waterproofing Systems can restore your surface long-term

What Is Spalling Concrete?

Spalling occurs when the top layer of concrete begins to flake, chip, or peel away, exposing the rough aggregate underneath. This happens due to chemical reactions and moisture infiltration inside the concrete.

Common symptoms of spalling concrete include:

  • Flaking or chipping surface
  • Pitting or holes
  • Exposed rebar
  • Crumbling edges or uneven finish

Why Does Concrete Spall?

Concrete spalling is caused by internal stress from moisture, temperature changes, or chemical reactions. Here are the top causes:

1. Rebar Corrosion

When water seeps through unsealed concrete, it reaches the reinforcing steel (rebar). The rebar rusts, expands, and creates pressure that cracks and spalls the surface.

2. Freeze-Thaw Damage

In colder climates, water trapped in concrete freezes and expands, breaking apart the surface over repeated cycles.

3. Alkali-Silica Reaction (ASR)

This chemical reaction between reactive silica and alkaline cement causes internal swelling and cracking.

How to Prevent Concrete Spalling

The best defense is keeping water out of your concrete.

Top Spalling Prevention Tips

  • Apply a concrete waterproof sealant like Semco’s Waterproofing Membrane or Microcement Kits.
  • Use a penetrating sealer to block moisture while maintaining breathability.
  • Ensure proper curing and mix design during concrete installation.
  • Reapply sealer every few years for lasting protection.

How to Repair Spalling Concrete

If your concrete is already damaged, you can repair it and prevent it from returning.

Step-by-Step: Repairing Spalled Concrete with Semco’s Xbond System

  1. Remove loose and flaking material using a grinder or wire brush.
  2. Apply X-Bond Liquid Primer to improve adhesion.
  3. Create a Scratch Coat: Mix 1 part Xbond Liquid with 2 parts X-Bond Stone and apply evenly.
  4. Build Thickness (if needed): For deeper areas, mix 1 part X-Bond Liquid, 1 part Brown Coat Additive, and 3 parts Xbond Stone.
  5. Finish Coat: Apply a 1:2.5 ratio of Xbond Liquid to X-Bond Stone for a smooth surface.
  6. Seal and Protect: Use Semco’s Titan Shield or Natural Shield for a durable, water-resistant finish.

Concrete Wall Spalling Repair

Repairing vertical surfaces such as basement or retaining walls requires careful prep:

  • Cut around the damaged area (approx. ⅜ inch deep).
  • Remove broken concrete and clean rust from the rebar.
  • Apply anti-rust paint to the exposed steel.
  • Refill the cavity with new mortar or repair mix.
  • Smooth and seal to protect from future moisture damage.

Fixing Spalling on Driveways & Sidewalks

Horizontal concrete surfaces like driveways and walkways are especially prone to spalling due to weather and wear.

Resurfacing: The Best Fix for Driveways

Instead of removing the entire slab, resurface it using SEMCO’s X-Bond Microcement system. This microcement coating bonds to the existing concrete, fills cracks, and creates a fresh, durable surface.

For added protection, apply a penetrating sealer such as RexPro’s Concrete Sealer to block water absorption and extend surface life.

Why Choose Concrete Resurfacing?

Concrete resurfacing not only fixes spalling but enhances the surface:

  • Restores aesthetics and strength
  • Prevents moisture intrusion
  • Reduces maintenance costs
  • Offers decorative or textured finishes

Whether you’re repairing a small area or revitalizing an entire driveway, resurfacing provides a long-term, cost-effective solution.

Final Thoughts

Spalling concrete may start as a cosmetic issue, but it can quickly lead to structural problems if ignored. Fortunately, with SEMCO's X-BOND Microcement system and waterproofing sealants, you can:

  • Repair existing damage
  • Prevent future spalling
  • Enhance your concrete’s appearance and durability

💡 Ready to restore your concrete?
Order your concrete repair and waterproofing products today from SEMCO SPACES and protect your investment for years to come.

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