Causes of Craze Cracking

Hotline Problem

What causes the fine random cracks that show up on a flatwork surface, especially after if gets wet?

Troubleshooting Response

They're called craze cracks or crazing. Usually the cracks develop at an early age and are no more than 1/8-inch deep. They don't affect strength and rarely affect durability or wear resistance but they are unsightly. There are many possible causes:

  • Using concrete that's too wet
  • Excessive use of a jitterbug
  • Overfloating the Concrete
  • Finishing while there's bleedwater on the surface
  • Sprinkling cement or a cement-sand mixture on the surface to blot up bleedwater
  • Intermittent wetting and drying during the curing period
  • Early drying of the surface before curing begins

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