Freeze-Thaw Effect on Concrete
In several parts of the country this spring, temperatures will have dramatic swings. This freeze-thaw cycle can lead to significant concrete damage on exterior surfaces like sidewalks, curbs, and more.

Why Does Freeze-Thaw Affect Concrete Surfaces?
Concrete is a porous surface, meaning it absorbs water. Water sitting on concrete, like melted snow and ice, will fill the pores of the concrete. When the temperature drops, this water will freeze and expand. The frozen water within the concrete is roughly 9% greater than when it was absorbed as a liquid. This expansion causes pressure within the concrete, sometimes causing it to crack. In addition, the frozen water also causes the concrete pores to expand. This can lead to even more water coming in during the next thaw and the cycle continues to repeat.
What Types of Damage Can Freeze-Thaw Cause on Concrete?
Freeze-thaw damage is typically the cause of two types of concrete damage: cracking and spalling.
Cracking
As described above, the pressure from the water freezing and expanding will cause cracks within the concrete. These cracks can be below the surface, so they are not visible. As time passes and more freeze-thaw cycles occur, the cracks may start to travel up to the surface.
Spalling
Spalling occurs when water on the surface freezes and the external layer fractures and falls off. This exposes the underlying aggregate.
What Can I Do About Freeze-Thaw Damage?
While we can’t control the weather, there are steps to take to protect against concrete damage caused by freeze-thaw cycles.
- Limit water sitting on the concrete from rain, snow, or ice. Adjust drains, gutters or other rain control methods to run directly to the ground instead of the concrete surface. Brush standing water off concrete before the freeze occurs.
- Control groundwater. Make sure the earth is well drained and slopes away from the concrete surface.
- When damage is apparent, but the concrete sub-base is still viable, concrete resurfacing options are available. This will repair damage and add to the strength of the existing concrete without tearing it up to replace it. Most concrete resurfacing solutions have additional protective layers to prevent future freeze-thaw damage.