What Temperature is Too Cold to Pour Concrete?

Sometimes things on your to do list need to get done – even in the depths of winter. If you’re managing a concrete parking lot or structure that’s past due on repairs or replacement, it’s important to knock those issues out before they create hazards for your tenants or visitors – but what about when it’s cold out?

Temperature plays a big part in concrete’s curing time and sometimes temperature can prevent you from doing any concrete work at all, but what’s the limit? What if you need to repair potholes in December? Let’s learn more about temperature and concrete and find out limits on what temperature is too cold to pour concrete in. You might not be able to do everything in Winter, but you’ll be surprised at what you can accomplish.

What Temperature is Too Cold to Pour Concrete?

Concrete Drying vs Curing

To avoid confusion let’s make something clear, concrete doesn’t dry – it cures. Drying is a physical reaction while curing is a chemical reaction. When water is introduced to the cement portion of concrete the chemical reaction begins. Because curing is a chemical process and not a physical one, concrete doesn’t require conditions you’d imagine.

Concrete doesn’t need warm temperatures or sunlight to cure and can set in the rain. Concrete’s curing properties are so strong that concrete can theoretically cure underwater. At the correct temperatures most concrete is cured enough for foot and vehicle traffic within 2-3 days of installation though the actual curing process will go indefinitely.

Does Temperature Affect Concrete Curing?

Though it cures as opposed to dries, temperature plays a large role in concrete installation and can greatly affect curing. Too cold and the curing will take too long. Slow curing means brittle concrete that’ll never set properly. Concrete that sets in below freezing temperatures without any insulation will need to be dug up and repoured.

Too hot and the moisture in the concrete will evaporate too quickly, causing weakness and crack-inducing shrinking. If it’s too hot when the concrete is poured it might have to be replaced. Repouring concrete will cost time and labor so never attempt to pour in temperature extremes.

What Temperature is Best for Pouring Concrete?

As we learned above temperature does affect concrete curing but what temperature is too cold to pour concrete? What about too hot?

The ideal temperature range for pouring concrete is 40 to 60 degrees over a 24-hour period. Between 40 and 60 allows the water to slowly evaporate from the concrete but is not cold enough to slow down the chemical process of curing. While it’s feasible to install concrete above 60 degrees, it’s normally not a good idea to install in temperatures below 40.

Tips and Tricks for Winter Concrete Installation

  • Thawing the Ground – Sometimes you can’t wait for perfect 40 to 60-degree temperatures for concrete installation but that’s okay if you thaw the ground prior to installation.  You can thaw the ground with a combination of physical earth removal, heating systems, and insulating blankets. Concrete contractors that frequently install during the colder months will use these tools for the best pour possible.

  • Warming Blankets – Imagine this situation: You’ve just poured a fresh concrete lot on a balmy 55-degree day and are cleaning up. You check the weather report and there’s been a dramatic change – it’s going to dip below freezing! No worries, you can tuck your concrete in for naptime. Concrete contractors can use large-scale industrial warming ‘blankets,’ that are placed on curing concrete during freezing temperatures. The blankets keep concrete at ideal temperature for approximately 24-48 hours until it’s set and ready for traffic.

  • Hot Water Mixing – Ideally you or your concrete contractor will use hot water for the concrete mix. Hot water helps the curing reaction work its magic when it’s a bit cold outside. Concrete should be 65 degrees or above when poured on your parking lot.

Choosing a Great Concrete Contractor for Winter Installation

Ultimately your concrete contractor will determine the best day for install by using a combination of forecasts and local knowledge. Your concrete contractor wants happy customers and doesn’t want to take the financial hit of re-doing your job, A reputable contractor will only schedule installations during viable winter days.

In Colorado temperatures regularly go past 40 degrees in the winter, making year-round Colorado concrete installation viable no matter what the calendar says. If you need to replace your Colorado parking lot now, don’t wait until spring, call Colorado Pavement Solutions to explore our options today.

Get Your Winter Concrete Questions Answered

Colorado Pavement Solutions has been helping Colorado customers pour concrete for years, including the colder months of December through February. We have the people, skills, and tools to plan a winter install and give you an excellent job every time. Give us a call today to get your concrete project started, even if it’s a little chilly out.