Concrete cancer and concrete spalling: the causes and method to repair

What is concrete cancer?

  • The concrete that has developed cracks and separated from the substrate.
  • Common signs: corrosion, flaking, cracking, disintegrated concrete, rust stains or roof and walls leaking.

The causes of concrete cancer and spalling

  • Chloride corrosion in saltwater.
  • Unusual weather.
  • Improper reinforcing steel preparation.
  • Concreting done incorrectly.
  • Failure of waterproofing: Concrete deterioration can begin when a waterproofing membrane breaks or when there are cracks surrounding the membrane.

Why are concrete spalling repairs necessary?

  • It is unattractive as the customers will presume that no proper maintenance has been done for the buildings which the value of the asset will diminish directly as the demand drops.
  • If the structure is in a location that is accessible to both the general public and employees, spalling could be dangerous due to falling debris or trip hazards.
  • The structure could become unstable.

How to repair concrete spalling?

There are 3 types of methods to repair concrete spalling, including: –
  1. Formwork Grouting Method.
  2. Patch Repair Method.
  3. If the integrity of the structure is threatened, structural strengthening has to be considered.
The steps are rationalized as follow: –
  1. Remove all the cancerous concrete.
  2. Follow the engineer’s provided scope of work.
  3. Ensure the integrity of the exposed reinforcement.
  4. Prepare and treat the existing concrete and steel reinforcement, and replace any steel that is too badly corroded or rusted.
  5. Put in place strategies to prevent the recurrence of the issue.
    • Examples include the installation of drains, new slabs, or stronger flashings.
    • To stop water ingress, apply waterproofing membranes or coatings.
    • The use of appropriate and authorized concrete restoration products.
    • Permit adequate time for the repairs to cure.
  6. Keep an organized record of all work done so that the engineer may access it.
  7. Make-good: Restoring the structure to its original (or better than original) condition.
    • The facade could be improved with new textures, paints, or protective coatings; or
    • Potentially restoring the facade to its prior condition.
  8. Document the precise location and information about the restored areas.
Water ingress into the concrete reacts with the steel causing steel corrosion in most of the cases of concrete cancer. As such, effective waterproofing is necessary to prevent the recurrence of the concrete spalling issue. Please visit our blog categories for the waterproofing system at visit our projects reference at

Key Takeaways

Concrete spalling must be fixed immediately once you have detected it as this problem is not a sudden event. Treating the visible signs (aesthetic) alone will not solve the problem; in fact, it will deteriorate the problem. We have seen too many cases which they applied a paint coating without fixing root cause.

Please do not hesitate to contact us if you require more information. Our team will be happy and glad to assist you.

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