What Does Different Weather Do To Concrete?

Bad weather can wreak havoc with your concrete when you’re trying to get a consistent pour and only have a specific window to allow for curing. The conditions in which you pour your concrete can have a bearing on the consistency you need for your mixture, along with the various results in the finished product — especially when it’s extreme weather you’re working against. 

While weathering of concrete itself once it’s been cured into place is one issue – erosion from water for example – an even more important factor to consider first is whether you can pour concrete in adverse weather conditions. Whether it affects the cement and the curing time or just makes it difficult to get the job done, it’s worth some consideration on each individual project you tackle to get the best results.

At EasyMix Concrete, we’re experienced concrete experts for Hertfordshire, Bedfordshire and beyond, and we wanted to share our rough tips on pouring concrete in the Great British weather! 

Can you pour concrete in the rain?

Will your concrete set in the rain? Can you even pour concrete if it’s raining? These will be the kinds of questions you’re asking yourself if you’ve got a job to do and a forecast that shows back-to-back rainy days.

Ideally, you want to avoid rain, so try to arrange your pour for the day forecast for the least rain possible. However, it’s hard to avoid those grey skies here in the UK, so yes, you can pour your concrete while it’s chucking it down, you just need to be prepared. Rainwater getting into your concrete mix can add too much liquid or pollutants and could wash out some of your cement, so you should do your best to avoid letting rainwater into your concrete if you’re mixing on site.

Once poured, you should immediately cover it with a tarp to allow it to cure. Even if it’s not raining as you pour, it might do so later, so it’s better to be safe than sorry.

Can you pour concrete in a heatwave?

While the climate here in the UK is generally mild, we do get the odd hot week. Heatwaves are defined by periods of long, hot and dry weather, which can pose a few unique challenges to pouring concrete. 

The biggest issue for concrete during a heatwave is the impact it has on the curing process. That’s because concrete uses hydration as part of the curing stage. In simple terms, this is a chemical reaction that makes the cement and water set. With that in mind, if the heat in the air is speeding up a loss of water from your mixture, you can probably expect it to impact the strength of the cured concrete. 

If your mixture loses too much water, it can shrink, crack or even flake. But yes, you can pour concrete in a heatwave. Here are some things you can do to help get the job done and avoid the issues mentioned: 

1. you should try to pour early or late in the day during a period of hot weather, as it should be cooler
2. you can also combat heat by keeping everything in the shade as much as possible and by wetting down any forms to lower the temperature

Can you pour concrete when it’s snowing?

Snow is quite rare in the UK, but it does happen. Thankfully, this won’t stop you from pouring concrete, as long as you keep the pour site clear of snow. You should never lay concrete on a frozen surface or one covered in snow, so it’s worth using tarps to protect the site before and after.

Extreme cold can impact your finished product, so we’ll touch on laying concrete in cold temperatures later in this piece.

Can you pour concrete on a windy day?

High winds can make life uncomfortable for you and any team you have, and it’s pretty inconvenient having things blown across your site. However, it doesn’t prohibit you from pouring concrete if you prepare properly. 

The only issue you need to be wary of is that it can cause your top layer of concrete to cure faster through evaporation, which can lead to cracking or flaking in the finished product. You can remove this worry by erecting windbreakers around your pour site to help you with steady pouring or pumping and to limit the amount of shrinkage.

When is it too cold to pour concrete?

We’ve already mentioned that pouring concrete in the snow can be done, but it requires extra effort and planning. What you also need to consider, however, is what temperature concrete can be poured in. It needs to be at least three degrees centigrade at the time of pouring, both in the air and for your surface, because you don’t want any ice to form in your concrete mix.

If ice does form in your mixture due to low air or ground temperatures, you won’t get the required strength. One way to try and circumvent this issue is to have some heaters nearby, but this may only work in an enclosed space and will no doubt cost you extra money to run. 

Here at EasyMix Concrete, we’re used to the ever-changing weather conditions that we get across the year, so if you need more advice and guidance on concrete pouring in Hertfordshire and Bedfordshire and the surrounding areas, simply contact us today. You can also call us to schedule your volumetric concrete or ready mix concrete delivery at a time that suits you, helping you negotiate any tricky weather conditions.