Cold Weather Concreting – Protection Is Essential

concrete blanketWhen pouring concrete in cold weather, temperature protection is critical. Dropping temperatures and wet elements will lengthen the curing time of concrete and create costly delays while waiting for it to set. Delays virtually always lead to you losing money, so it’s imperative you find a solution to help your concrete set faster when the weather says otherwise. 

The American Concrete Institute defines cold weather concreting as:

“A period when for more than three successive days the average daily air temperature drops below 40° F and stays below 50° F for more than 21 hours.”

Low temperatures means concrete takes longer to set due to moisture being trapped in the concrete. This is because cold weather prevents evaporation of the water in the concrete mix. The faster the water evaporates, the faster the concrete hardens. The less water evaporates, the longer the concrete will sit there before curing completely.

How Long Does Concrete Take to Set?

The length of time concrete takes to set depends on if additives were mixed into the concrete, but generally it takes 28 days. At that point, concrete is considered fully set, but in reality concrete never stops curing. Concrete that hasn’t reached 28 days can still be walked on starting at 48 hours after pouring, and will reach 70% of compressive strength after 7 days.

What temperature is too cold to pour concrete?

In normal conditions, laying concrete in cold weather is best done when the air temperature is between 50-60°F. Try curing below that, and the water within the concrete will begin to freeze, weakening the overall strength of the concrete.

What happens to concrete if it freezes?

In addition to taking longer to set, water that freezes in the concrete will inevitably lead to cracking. Though all concrete is expected to crack over time, it can be controlled and guided when setting within the ideal temperature range for curing. Frozen concrete leads to uncontrollable cracking, and must be mitigated by providing heat to the concrete in the early stages of curing.

What Options are there for Cold Weather Concrete Curing?

There are a number of options out there when laying concrete in cold weather to help it cure when the temperature isn’t in your favor:

  • Chemical additives: additives in liquid or powdered form are added to the cement mix in order to better control hardening.
  • Concrete curing blankets: these blankets create a layer of heat above the concrete, allowing water within the concrete mixture to evaporate faster and increase curing time without compromising durability.
  • Hydronic heating systems: heated propylene glycol keeps curing concrete at stable, even temperatures.
  • Poly/tarp cover with forced air heat applied: insulated tarps cover the concrete to keep cold out, while an attached heating unit blows hot air across curing concrete.

Costly cold weather consequences

In some situations, there is the luxury of project postponement in favor of better climate temperatures. In most cases, however, schedules and deadlines make it necessary to place concrete in less than favorable conditions. Penalties and fines for not meeting defined schedules can be the difference between a profitable or unprofitable job. In these cases, all factors need to be taken into consideration. Ensuring proper concrete curing while sustaining concrete strength and durability is critical. 

How Can I Speed Up Concrete Curing?

Keeping concrete in the warm can be difficult when the temperature is below ideal for setting. However, cold weather can be mitigated if you are prepared to deal with it. The most important thing to remember is that the concrete temperature needs to be kept high in order for the water inside it to evaporate.

concrete curing blanket
Powerblanket’s concrete curing blanket is the choice solution for many winter concrete layers.

Powerblanket recommends the following tips to protect concrete from frost:

  • Use heaters or concrete blankets to thaw surfaces where concrete will be poured. Pouring concrete on frozen ground will quickly cool concrete well below ideal temperatures. Using a heater or blanket to prepare surfaces will prevent too-quick cooling or freezing and help keep the necessary reactions within the concrete going.
  • Mix cement using hot water to help increase the temperature of the concrete.
  • Store materials in a warm location, or use a portable hot box to maintain materials under a constant temperature.
  • Use quick-set cement during cold weather. It may set more slowly than the instructions indicate, but will still harden more quickly than traditional cement mix.
  • Mix in additives that accelerate curing time.
  • Use extra cement to make the reaction hotter and cause concrete to hydrate more rapidly.
  • Utilize squeegees or a vacuum to remove bleed water that has a difficult time evaporating during colder weather.

By utilizing these tips when pouring concrete in the winter, you can prevent damage as a result of freezing at an early stage of cure, maintain development of sufficient strengths in a timely fashion, ensure durability and long-term structural integrity, and keep your project on schedule.

For additional information about cold curing concrete procedures, check out this article about how temperatures impact concrete that is still curing in Nevada’s Hoover Dam.

Concrete curing solutions from Powerblanket

Don’t wait until the last minute to choose a proper heating solution. Concrete curing blankets from Powerblanket are proven to speed up curing time and keep concrete protected while curing. 


Cure your concrete faster and better in cold weather conditions with Powerblanket.

Curing Cold Concrete: Electric vs. Insulated Blankets

Electric concrete blankets versus insulated blankets. Which one is best and why is it Powerblanket?

Not All Concrete Insulated Blankets Are Created Equal

If you happen to read almost any do-it-yourself guide, you will likely see a sentence that says, “If temperatures are below 40°F, use insulated blankets or straw to keep your freshly-poured concrete from freezing.” Well, that sounds nice and easy, but simply keeping concrete from freezing isn’t enough.

Why Heat Concrete?

The optimum range for proper concrete curing is between 65° – 85° F. When concrete dips below that range, ice crystals can form, cure strength will be compromised, and several temperature based defects can occur. Concrete pouring is a critical stage in any construction project and problems derail progress when it needs to be repaired or re-poured. Solely insulating concrete during curing seems appealing and money-saving, but can lead to costly time delays and expensive re-works.

What is Thermal Insulation?

Simply put, thermal insulation reduces the transfer of heat between objects. There are a myriad of both natural and synthetic materials used to insulate objects in different industries. When thermal insulation is placed on something that is already warm, it will prevent heat from escaping.

The chemical reaction of concrete formation is exothermic and does create some heat. This heat can be trapped (to some degree) with the use of insulating blankets or straw. But if it’s cold enough outside, insulating blankets won’t keep the temperature at an ideal level for maximum curing.

Insulation + Heating

When pouring concrete in cold weather, providing thermal insulation is only half the battle. Most insulated blankets will not provide enough surface contact to effectively insulate your concrete on really cold days. Combining the protective power of insulation plus even heat distribution gives you an advantage over mother nature.

Electric concrete heating blankets provide the protective layer of insulation and an extra boost of heating power to keep your concrete between 65° and 85° F. Concrete blankets have 10x more surface contact than other blankets. They efficiently transfer heat down into your concrete while heavy-duty weather-proof insulation protects it from the elements and heat-loss.

Thaw Before Your Pour

No insulating blanket on its own will thaw frozen ground, and pouring concrete on frozen ground can have serious repercussions.

electric ground thawing blankets

Electric ground thawing blankets are the best way to ensure your concrete pour gets off on the right foot. Using an electric ground thawing blanket prepares the ground before you pour so ambient temperatures above and below your concrete are at ideal levels.

Concrete Curing BlanketsMany factors have an effect on concrete cure time, such as the type of mix used, the size and shape of the slab, and the ambient weather. Of all these factors, weather and temperature is the most unpredictable. The colder the temperature, the longer concrete will take to set and reach its proper strength. During cold weather, a conventional insulated blanket will cause the concrete to take longer to cure and will result in a weaker concrete.

For example, concrete kept at 70°F will set in approximately 6 hours, whereas concrete kept at 40°F will take 14 hours to set. Concrete maintained at 70° F will reach a compression strength of 2,700 psi in 3 days; concrete maintained at 40° F will only reach a strength of 1,200 psi in 3 days.

This disparity in strengths makes a huge difference in whether your construction project can proceed. If concrete takes too long to set, cure, and strengthen, your project can be significantly delayed. Some concrete manufacturers find it too problematic to operate during the winter, creating a costly off season.

Concrete Solutions From Powerblanket

With Powerblanket, there is no off season. The difference between conventional insulating concrete blankets and electric concrete curing blankets is clear, and our electric blankets are a cut above the rest. By combining heavy weatherproof insulation with electric heating components, Powerblanket can cure concrete 2.8 x faster than conventional insulated blankets.

Our ground thawing blankets melt ice and snow and prepare the ground before your concrete is even poured. Our concrete curing blankets then maintain the temperatures you need to more quickly cure your slab to a strong finish. Powerblanket can eliminate costly weather delays, ensure your project proceeds on schedule and that your concrete will be long-lasting and durable. Contact us to find the right concrete solution for your needs 855.440.0208 or [email protected].

Cure your concrete faster and better in cold weather conditions with Powerblanket.


Shelby Thompson

Shelby Thompson is the head of standard product sales for Powerblanket. He has a distinguished military career, having served in both Afghanistan and Iraq. In his time in the Marines, Shelby acquired an impressive skillset that he now uses in his current role. When he's not working, Shelby loves spending time outdoors with his wife, son, and daughter. He is also a semi-keen hunter, fair weather fisherman, and shooter. Unfortunately, Shelby also has something of an unlucky streak when it comes to Fantasy Football at the company.