How to Pour Concrete in Hot Weather
For many of us, the summer months are the best time of the year.
From barbecues to beer gardens, the hope of warmer weather offers a whole host of possibilities.
But for those working in the construction industry, soaring temperatures can provide their own issues.
In recent years, British summers have been getting hotter and hotter.
In fact, on the list of top five hottest days in UK history, four have taken place since 2019 and 2022 even saw the first ever 40°C day.
With this in mind, tasks like pouring concrete can be made more difficult.
Ahead of the summer months, the team here at South Coast Concrete has put together a handy guide outlining how to pour concrete in hot weather.
Does hot weather affect concrete?
Yes, extremely high temperatures can negatively affect concrete in a number of ways.
Firstly, it can ruin your mixes’ consistency which is usually identifiable by a reduced slump. Some people will add more water in an attempt to counteract this, but this may reduce its overall durability and strength.
As well as this, it can cause concrete to set quicker. This is a problem because it means there is less time for compacting and finishing which could undermine the integrity of your mix.
Finally, as the heat speeds up the loss of moisture in concrete, it can make it more prone to cracking.
How to pour concrete in hot weather
If you need to pour concrete during a heatwave or particularly hot weather, there are several precautions you can take to avoid the negative effects listed above.
Prepare your site
You should pour concrete as soon as it arrives at your site in order to avoid it getting hotter during the day. With this in mind, it’s important to prepare your site beforehand. This includes creating some makeshift shade in the area where it’ll be poured, clearing routes to allow delivery vehicles easy access, ensuring all other necessary work has been completed and more.
Dampen the sub-base
It may also be worthwhile to slightly dampen your sub-base prior to pouring your concrete mix. Use a small amount of water on the sub-base and timber formwork as this will help to cool the area down which will be useful for the hydration process.
Opt for ready-mix concrete
Ready-mix concrete is perhaps the best type to use when working in extremely hot weather. This is because no mixing is required and it can be poured straight away.
For additional protection, you could also use a concrete pump to shield the mix from the heat.
Take precautions against the heat
There are also a few additional precautions you can take against the heat. Firstly, try and schedule your pouring for the coolest part of the day. Usually, this will be before noon and after 3pm. You can check the weather forecast to be sure of the most suitable time on any given day.
It’s also worthwhile keeping any tools you will be using in the shade to prevent touching your concrete mix with hot equipment.
Also, remember to look after yourself and your staff when working in these hot temperatures. Regular drink breaks are recommended and suncream should always be applied.
At South Coast Concrete, we’re expert concrete suppliers for both domestic and commercial projects in Portsmouth, Southampton and Chichester. As well as being able to help you with professional advice on pouring concrete in hot weather, we can also provide your next project with customised mixes and leading concrete services to enhance your work. For more information, contact our team today.