Minnesota's freeze-thaw cycles are one of the biggest enemies of concrete surfaces. When water seeps into tiny pores and cracks in concrete, it expands as it freezes — by up to 9 percent. This expansion creates enormous pressure that can crack, chip, and crumble even the strongest concrete over time. Understanding how to protect your concrete can save you thousands in repairs.
The most important step you can take is sealing your concrete. A high-quality penetrating sealer fills the pores of the concrete and prevents water from getting inside. We recommend applying a sealer within the first year of installation and reapplying every two to three years. This is especially important for driveways, sidewalks, and steps that are exposed to rain, snow, and ice.
Proper drainage is another critical factor. Water that pools on or near your concrete surfaces is a recipe for freeze-thaw damage. Make sure your concrete is graded to direct water away from the surface, and keep gutters and downspouts clear so water doesn't collect near your foundation, steps, or walkways.
Be careful with deicing chemicals. Rock salt (sodium chloride) is one of the most common deicers, but it can be harmful to concrete — especially new concrete that hasn't fully cured. Calcium chloride and magnesium chloride are generally safer options. Better yet, use sand for traction without any chemical damage. Never use ammonium nitrate or ammonium sulfate on concrete surfaces.
Expansion joints are your concrete's built-in defense system. These gaps between sections of concrete allow the material to expand and contract with temperature changes without cracking. Make sure these joints are kept clean and filled with a flexible sealant. If you notice missing or deteriorated joint material, have it replaced before winter.
Finally, address cracks early. Even small cracks can let water in, and once water gets inside and freezes, those cracks will only get bigger. Fill minor cracks with a concrete crack filler as soon as you notice them. For larger cracks or structural issues, call a professional to assess whether repair or replacement is the best option.
At John & Jerry, we build every concrete project with Minnesota winters in mind. From the right concrete mix to proper joint placement and drainage planning, we set your concrete up to last. Give us a call if you have questions about protecting your existing concrete or planning a new project.