Can You Pour Concrete in the Winter?
Summer is the most popular time for concrete work. The days are long, temperatures are warm, and homeowners are ready to knock out summer projects.
While summer is the most popular time of year for concrete work, your concrete’s condition might not always be in line with the seasons. What happens if you get a huge crack down your driveway in January? What if your parking lot badly needs to be repaired in December? Can you pour concrete in the Winter?
Let’s learn how concrete works, how cooler temperatures can affect concrete’s performance, and tips on pouring concrete during the cooler months.
How Concrete Works
Yes, you can pour concrete in the winter, thanks to how concrete works. Concrete doesn’t harden by drying but curing. When water mixes with the cement and aggregate it creates a chemical reaction to bond everything together. Unlike physical reactions, chemical reactions aren’t affected as much by moisture and temperature – that’s why you can pour concrete underwater and in colder weather.
What is Considered Cold Weather When it Comes to Concrete?
Concrete isn’t perfect and there are some limits on when you can pour it. For concrete purposes, the American Concrete Institute (ACI) defines cold weather as “anytime the air temperature has fallen to, or is expected to fall below, 40°F.”
When concrete is poured below the cold weather limit it can have problems curing, leading to premature aging, cracking, and a greatly shortened lifespan. You can pour concrete in the winter but you’ll have to take extra precautions if the temperature is below 40.
You should never pour concrete in freezing temperatures. Concrete poured at freezing or below will not cure properly and will need to be replaced.
Benefits of Pouring Concrete in Winter
Easier Scheduling – Winter is the slowest time of year for concrete contractors so it’s easier to contact staff, schedule your job, and get the job knocked out in a timely manner. In winter the contractor can likely get you on the schedule within a few days compared to weeks or months.
Can be Optimal – Very cold is never optimal for concrete installation but kind of cold is. According to the ACI, concrete that is properly poured and cared for in colder temperatures will have more strength than the same installation in warmer weather.
Tips for Pouring Concrete in the Winter
Watch the Weather – Winter in the country can see temperatures anywhere from -40 to 100 degrees during the winter, but most areas average winter temperatures from 20 to 60 degrees. You’ll want to watch the weather forecast and look for prolonged periods of above 40 degrees, even if that includes minor precipitation. Ideally you’ll find 2-3 days where the temperature exceeds 40 around the clock.
Choose the Right Mix – A concrete mix that’s been amended for colder temperatures has a much better chance at giving you the perfect pour. Namely, you need it to be a strong mix. Concrete crafted for durability will do better at handling any freezing and thawing cycles without cracking or becoming damaged. Colder weather concrete is also known as air-entrained concrete.
Note: Concrete in cooler weather requires much more cement in the mix to bond everything together. The contractor might pass the expense to you or be happy to take the work during the winter season without passing the buck.
Prepare the Site – Proper site preparation is one of the most crucial steps to pouring concrete in the winter. Any forms like wooden panels need to be preheated to at least above freezing, all water mixed into concrete mixes should be at least 140 degrees while any aggregate should be preheated to at least 180 degrees.
Preparing the site also involves removing any snow, ice, or standing water that could mix into your concrete and ruin the pour.
Lastly the ground needs to be warm enough for a pour. Concrete contractors use electric blankets, torches, and friction to warm the ground before the pour.
Watch the Temperature – If you follow the earlier steps you’ll have a few days of great weather for your pour but concrete poured in colder weather needs to be closely monitored. You want the driveway to cure at a moderate pace but cold temperatures can affect proper timing. Contractors use electric blankets and infrared thermometers to monitor concrete’s temperature during curing.
Learning More About Pouring Concrete in Winter
You can pour concrete in winter if you choose the right days, the right materials, and the right techniques for the job. For more help with winter concrete installation contact the experts at Colorado Pavement Solutions. CPS has the people, knowledge, and tools to do your concrete driveway the right way – even during the winter.