How cold is too cold to pour concrete? And what should you do if it’s swelteringly hot, but you need to make a concrete repair? While you can pour concrete in cold and hot weather, it’s necessary to take certain precautions to ensure the concrete sets properly.
Your pavement repairs will not always conveniently fall at the times of the best temperatures for pouring concrete. For this reason, our team at UNIQUE Paving Materials compiled tips and information to help you achieve the best outcome on your project. Learn more about how to pour concrete in hot weather and cold weather from our informational guide today.
What You Need to Consider for Concrete Projects
First, it’s not only important to consider ambient temperature but also how you will keep the concrete at the correct temperature while it cures. When pouring concrete in cold weather, many people use heated enclosures or insulated blankets to prevent the concrete from freezing. Alternatively, windbreaks, sunshades, evaporative retarders, and sufficient manpower are necessary for proper curing when pouring concrete in hot weather.
Learn more about hot and cold weather concrete pouring procedures, concrete curing temperature ranges, and tips for curing below.
Temperatures for Pouring Concrete
Elements like volume changes, cracking, humidity, wind speed, and temperature all should be accounted for when pouring concrete. Experts agree that the best temperature for pouring concrete is between 40 °F and 60 °F.
The Issue with Pouring Concrete in Cold Weather
When temperatures dip below 40 °F, the chemical reactions that strengthen concrete slow down and can lead to weaker concrete. If concrete curing temperatures are below freezing, the water inside the concrete can freeze and expand, resulting in cracks in your surface.
So, it is important to note that when you pour concrete in cold weather, you are also following the same cold-weather procedures all the way to when the concrete is done curing.
Problems That Occur When You Pour Concrete in Hot Weather
According to the American Concrete Institute, hot weather is more than just air temperature. Hot weather is defined as ambient temperatures above 90 °F, including low humidity and high wind speeds. In conditions hotter than 77 °F, the water used to hydrate and cure the cement can evaporate, increasing the concrete’s temperature and presenting problems such as weakness, shrinkage, and cracking.
However, proper precautions help you successfully pour concrete during hot or cold weather. Here are some tips to ensure your concrete project is done the right way, even if you’re working outside that ideal 40 °F to 60 °F window.
Tips for Pouring Concrete in Cold Weather
When you pour concrete in cold weather, maintaining the correct temperatures for the curing process is extremely important. Concrete must be completely set before it is exposed to freezing temperatures. You can overcome cold weather challenges by following the tips below:
- Store concrete materials in a warm, dry place
- Thaw frozen ground, snow, or ice with heaters
- Use cold-weather products designed to cure fast
- Use hot water to mix your concrete
- Create a hotter reaction by using extra cement (e.g., 100 lb per cubic yard)
- Use squeegees or a vacuum to quickly remove bleed water
- Do not remove frameworks until the concrete has cured
Tips for Pouring Concrete in Hot Weather
On the other hand, if you’re pouring concrete in hot weather that exceeds 77 °F, it’s important to plan ahead. Offset detrimental effects from heat, humidity, and wind with the following tips:
- Avoid pouring during the hottest parts of the day
- Use sunshades or windbreaks for protection
- Store bags of concrete in the shade, garage, or other cool areas before using
- Dampen the subgrade before pouring your concrete slab
- Add ice to your concrete water mix to help cool down temperatures
- Once water is added to the mix, reduce the mixing time
- Make sure you have help, from managing the pouring to overseeing the curing process
Pouring Concrete Frequently Asked Questions
Along with the ins and outs of pouring concrete in hot weather and cold weather, our team has included some of our most frequently asked questions with helpful answers.
When is the best season to pour concrete?
Dependent on where you live, the different seasons can host various temperatures that could be considered ideal for pouring concrete. You should not be pouring concrete in hot weather or pouring concrete in cold weather unless you are fully prepared with the right materials, practices, and placements. Failing to do so can result in weak pavement that will not last.
If you are still curious about the best season or temperature to pour your concrete, check out some of the seasonal pouring tips based on your region.
Can I use chemical deicers or salt on concrete in the winter?
You can technically use salt and deicers on your pavement, but they will affect the overall integrity of your foundation. Deicers can contain not only salt but other harmful chemicals, such as ammonium sulfate and ammonium nitrate, that rapidly degenerate concrete. So even if you have followed all of the measures to correctly pour concrete in cold weather, you can have adverse effects from placing harmful chemicals on your pavement.
If you are wanting to properly thaw your pavement and reduce the risk of damage now or in the future, our team recommends using either sand or some form of heat on your concrete for the best results.
Additionally, some of our pavement preservation products, such as our KOLD-FLO® Pourable Crack Filler or our RAVEL SEAL® Pavement Preservation Emulsion, can help prevent problems from the start and stop future issues from emerging.
How do I prevent cracks from forming on my concrete?
Based on your specific case, there are plenty of different ways to prevent cracking in your pavement, as well as ways to restore cracks that have already occurred. To learn more about some of the various cases, as well as effective UNIQUE solutions, here are some of the recent blogs that we would recommend:
- What Is Fatigue Cracking in Pavement?
- How to Prepare a Concrete Surface for Treatment
- Protect Concrete from Freeze/Thaw Damage with UNIQUE Paving Materials
- UNIQUE Paving Material Provides Products for Polished Concrete Floor Repair
Can I pour concrete myself?
With UNIQUE’s expansive product line, you can certainly pour by yourself. We supply a diverse array of premium concrete repair and pavement preservation products for those looking to get the job done the right way. So, whether you are pouring concrete in hot weather, pouring concrete in cold weather, or anywhere in between, consider using our products on your next project!
Have any additional questions regarding how to pour concrete in cold weather, hot weather, or in general? Luckily for you, our team of experts is here to help. Contact us directly with any questions you may have!
Can You Successfully Pour Concrete in Cold Weather or Hot Weather?
Pouring concrete in hot or cold weather is possible when you take the right steps and work quickly. Keep in mind, set times will vary depending on temperature, no matter the time of year.
For professionals and homeowners alike, pouring concrete can be a nerve-wracking experience, but it doesn’t have to be. With careful planning, you can achieve satisfying results in less-than-ideal temperatures.
Here are some frequently asked questions we see about temperature extremes and concrete that should help clarify certain aspects.
Will concrete set in cold weather?
Yes! Concrete will set in cold weather, but the process is slower and involves special considerations, and the rate of setting will depend on the actual temperature outside. When temperatures drop below 40 degrees Fahrenheit, the hydration reaction that causes concrete to set and harden slows down significantly.
More importantly, you need to protect this concrete. If it freezes before it can set completely, you might notice that it has decreased in strength and durability.
How cold is too cold to pour concrete?
The ideal range for pouring concrete generally falls between 50 to 85 degrees Fahrenheit. Pouring concrete at or below freezing temperatures generally is not recommended. As we stated above, anything below 40 degrees Fahrenheit can impact the hydration process.
If you absolutely need to pour concrete during this time, be sure to use concrete mixes with added accelerators and ensure that you are extra careful with curing measures. This might involve the use of insulation blankets, heated enclosures, or temperature-controlled water to encourage proper curing.
What temperature is too hot to pour concrete?
Concrete can be poured in hot weather, but extreme heat will deliver a new set of challenges. Temperatures above 90 degrees Fahrenheit are considered too high for concrete pouring. This is because water in the concrete mix can evaporate faster, which results in shrinkage cracks and less strength than concrete that cures under normal conditions.
Additionally, direct sunlight on a hot day can cause the surface to dry too quickly which results in surface cracking. For these reasons, we recommend waiting for the temperature to cool down to at least 85 degrees Fahrenheit before starting your next concrete project.
Does concrete dry faster in hot weather?
Concrete does not actually dry; it cures through a chemical reaction called hydration. The reaction occurs between water and cement particles, which results in a crystalline structure that gives concrete strength and durability.
While higher temperatures speed up the initial curing process, temperatures that are too high can negatively impact the curing process by making the concrete surface more prone to cracking.
What happens when concrete gets too hot?
Hot concrete is less workable which makes it harder to place. This could result in a rough surface finish and defects, which decreases the safety of the surface. It may also result in thermal cracking which happens when there is a significant temperature difference between the interior and surface of the concrete.
Discover How Products by UNIQUE Paving Materials Can Help
Now that you have the proper knowledge of pouring concrete of hot and cold weather, it is time to pick up the products needed for your project. Learn more about UNIQUE’s concrete repair products for patching, resurfacing, anchoring, vertical repairs, and more.
Contact us today or request a sample to start your next concrete project!