Just because the temperatures drop and grounds (and our extremities) freeze, doesn’t mean your projects and workload stop. If anything, now is a great time to get ahead before the rush of spring slab pour and internal floor scheduling.
But while the lower temperatures don’t stop the work, it does impact it, especially when pouring concrete in the cold.
A cold snap means slower curing of any concrete poured and the risk of frost reducing strength of the concrete. In this article, we share some tips of the trade that you could try to minimise these risks, so your work quality and productivity don’t dip like the temperatures do.
Concrete Curing in Cold Weather
Those that work with concrete day in and day out have shared several tricks they use when pouring concrete in the cold. These aim to protect concrete from frost, and reduce the risks that come with working in the cold weather.
Don’t pour concrete on frozen ground
While it might seem tempting at times to pour concrete onto frozen ground, especially when timeframes are tight, this will likely cause disaster later down the line.
Frozen ground expands as it defrosts, as it thaws it can settle unevenly. This means if you pour concrete on a frozen base, you risk:
- Cracking
- Loss of support
- Slab movement or failure
If you want to save yourself time, money and stress, you are better off waiting for the ground to defrost before pouring even the smallest amount of concrete.
Use insulated protection and temporary enclosures
Concrete curing in cold weather can be tricky. The process requires some heat to cure efficiently and to the desired strength. But when temperatures are consistently low, the material’s core temperature drops quickly, before the process finishes.
Many tradies use insulated protection. They provide a way of covering the freshly placed concrete with materials that retain heat generated by cement hydration.
These include:
- Insulating curing blankets,
- Straw or hay covered with plastic sheeting
- Rigid foam insulation boards
- Thermal tarps or mats
Using one of the above can protect the concrete against early-age freezing, which can permanently reduce strength.
An alternative to insulated protection is using a temporary enclosure. These temporary structures are built around the work area to create a controlled environment.
It might look dramatic to build these structures, but are a great way to protect concrete from frost because they shield concrete from wind, snow, and freezing air, allow use of heaters to maintain consistent temperatures and prevent rapid moisture loss due to wind.
This helps promote even concrete curing, building up strength and durability rather than losing it.
Consider accelerators and winter mix designs
Another way you could protect your concrete from frost is by adding chemical admixtures. These are often added into the concrete design mix to speed up setting time and early strength gain.
By adding either calcium chloride or non-chloride accelerators (such as calcium nitrate, calcium nitrite), you can offset slow hydration caused by low temperatures, help concrete reach critical early strength before freezing and reduce finishing and formwork delays.
The benefits of adding these accelerators to a winter concrete mix design mean the concrete should develop early strength faster which will lower the chance of freezing damaging its overall strength and durability.
Aggregate Storage in Winter
We know that it is one thing being told to keep your aggregates dry and warm, but it is a completely different thing making it a reality. So here are a few more tips and tricks from the trade that you can follow.
Store aggregates on a well-drained, hard-standing surface
This prevents contact with frozen or saturated ground, that would reduce the temperature or even wetten the aggregate.
Use covered stockpiles (tarps, sheds, or bins)
Covers offer protection to aggregates from snow, rain, and ice buildup.
Build stockpiles with a steep slope
Keeping stockpiles on a slope encourages water runoff and reduces ice accumulation, so the aggregates don’t sit in a pool of water or ice soaking through.
Avoid placing aggregates directly on the ground
You should use raised bins or barriers where possible, to keep materials off direct ground.
Remove snow and ice from stockpiles
It is important that you take any ice or snow out of stock piles before loading. Don’t do it during batching, because this will be too late.
Rotate stockpiles regularly
Consistent movement can prevent long-term freezing in the pile core, so the batch as a whole stays dry and warm, ready to use when you need it.
Consider heated aggregate bins
If you are working in a particular cold spell that is sticking around, it might be worth investing in a heated aggregate bin or steam thawing.
This reduces the likelihood that the stockpiles cool down and stops ice forming on any of the piles.
Monitor aggregate temperature and moisture content
Constant monitoring of your aggregates should be a part of your quality control process.
Make sure you are keeping an eye on the temperature of a stockpile and how wet it is.
Winter Site Working
Of course, the impact of winter hits more than pouring concrete and storing aggregates. It also affects how and when you work.
When pouring concrete in the cold, many tradespeople who frequently work with concrete say you should be planning to do it earlier in the day. This allows sufficient setting time and protection before night-time temperature drops.
Plus, when leaving it to cure overnight, you should take a few extra precautions to protect concrete from frost. Think about:
- Covering freshly placed concrete with insulated blankets or protective sheeting
- Ensuring protection is secure against wind, frost, snow, and rain
- Maintaining required curing temperatures overnight with additional heaters to prevent freeze damage
And don’t forget to amend your health and safety processes throughout winter to take into account the increase in risks on site. Steps you can take include:
- Brief operatives on winter-specific hazards (ice, reduced visibility, cold stress)
- Keep access routes, walkways, and working areas clear of ice and snow
- Ensure appropriate PPE is worn, including thermal and waterproof gear
- Review and update Risk Assessments and Method Statements (RAMS) to reflect winter working conditions.
Why bother with the above?
Planning and protecting concrete in winter provides clear commercial advantages: reduced delays, smoother finishes, and improved programme reliability.
By taking the right precautions, such as insulated protection, temporary enclosures, winter mix designs, and proper material storage, projects stay on schedule and maintain the high-quality standards clients expect.
AMS is your trusted partner for being winter ready, providing solutions and expertise that keep your projects moving safely and efficiently, no matter how cold it gets.
Buy the bagged or loose aggregates you need and enquire about ready-mix concrete collection or concrete delivery online today to keep your project on track and ready for a spring handover.