Concrete Sealing in Cold Weather

As fall turns to winter, temperature plays a critical role in sealing concrete. In fact, temperature is the number two cause of concrete sealing problems, second only to moisture. That means taking extra precautions to make sure concrete sealing is done right in cold weather.

When it comes to properly concrete sealing, both air and surface temperature play a role in proper sealing. Why? Once applied, sealers create a chemical reaction and the outside temperature decides how fast that reaction occurs—or if it happens at all. Most manufacturers recommend 50 to 90 degrees as the ideal temperature range for applying concrete sealer.

So what happens if you apply concrete sealer outside of that 40-degree range? Extreme temperatures will cause the sealer to apply too fast or too slow. Sealer reaction can also be affected by humidity, wind chill factor, and even time of day sealer is applied.

High temperatures cause sealer reactivity to increase. That means the hotter it is, the faster you’ll have to work to get the concrete sealer applied. High temperatures can result in “spider webs” when the solvent flashes before the sealer can form a film, or bubbles when the solvent flashes too fast and traps air.

Alternately, if the temperature is below 50 degrees, the chemical reaction slows and the time needed to properly seal concrete increases. Every concrete sealer has a minimum film-forming temperature (MFFT). This is the minimum temperature needed for the sealer to form a film, cure, and harden. If too much time passes, due to a too-cold surface temperature, you’ll end up with a weak sealer. If the temperature is significantly below the MFFT, curing stops completely, and a white residue will be left behind on the concrete surface. This is why it’s important to seal concrete properly before cold weather sets in.

As we transition from fall to winter and temperatures continue to drop, consider using concrete curing blankets to make sure concrete is properly cured and sealed. Remember, the colder the temperature, the longer it takes to cure and seal concrete. Proper curing and sealing of any concrete surface is critical to the projects long-term durability.

Click here to learn about different concrete sealers, or visit Intermountain Concrete Specialties for expert tips and the best concrete sealers in the industry.