How Long Does Concrete Take to Dry?
Concrete is perhaps the most important building material that is used in a whole host of domestic and commercial projects. Once it has been laid or installed, it can offer a whole host of benefits including strength, durability and excellent versatility.
Often, concrete is used to construct floors, roads, pavements or other structures that will experience heavy footfall from people and vehicles. With this in mind, it’s important that you give it enough time to dry before it starts being used. If not, the mix can be easily ruined.
One of the most important processes to observe is drying, or curing, concrete. This will see the concrete harden, meaning it can then be used for its intended purpose. If the concrete surface is used before this has properly taken place, it is likely all your hard work will be ruined and you will need to do the work again.
At Concrete Supply UK, we’re vastly experienced in constructing all kinds of concrete applications. This means our team is also extremely knowledgeable when it comes to the question ‘how long does it take for concrete to dry.’
In this article, we’ll take a look at how long it takes for concrete to dry, discuss curing concrete and explain how you can properly treat your concrete mix.
Read on to find out more.
How Long Does Concrete Take To Dry?
The concrete drying process is an absolutely fundamental part of every construction job, and it’s essential that you wait for the mix to dry fully before proceeding to the next stage of the project.
Drying times can vary depending on the type of mix you’re using, but on average it will take between 24 hours- 48 hours for the concrete to dry to a level where it can be walked or driven on.
It’s worth noting that concrete is always continuously drying. Even when it has dried to a suitable level that further work can be done on the surface, the drying process will still be going on in the layers below. You should be aware of this as it can impact the type of work you can and cannot do.
What Is Curing?
Going hand in hand with drying is concrete curing.
While drying refers to the evaporation of moisture, curing concrete is the process that makes the concrete harden. Curing gives the concrete its physical properties including being hard, durable and resistant to abrasion.
There are different curing methods that we will discuss later in this blog, but it’s important to distinguish between curing and drying.
How Long Does It Take Concrete To Cure?
Just like with drying, concrete continues to cure and harden throughout its lifespan. Each day the concrete will harden more and more, as the cement in the concrete bonds with water molecules. Tiny bubbles of water will continuously be present within the concrete, so even when the curing process has been finalised and an appropriate hardness level has been reached, it will continue to harden further.
However, in terms of usability, there is a timeline you can follow:
- 24-48 hours – After the concrete has been initially poured, you should wait between 24 to 48 hours before walking on it.
- Seven days – After a week has passed, heavy traffic from vehicles and equipment can be used on the surface.
- 28 days – After 28 days, or a month, has passed, you can assume the concrete has fully hardened and you can perform all types of tasks on the surface.
How Does Concrete Harden?
If you’re wondering how concrete actually hardens, it’s important to consider what is going on inside the mix.
When cement and water are mixed together, crystals will form. These crystals are extremely hard and provide the concrete with its strength. Assuming the concrete stays at a suitable temperature, these crystals will help the concrete to harden over time. However, if the concrete becomes too cold the crystal process will cease – meaning the concrete will become weak and cracks can occur.
As soon as the concrete begins to be poured, it will instantly begin hardening. However, this does not mean you can proceed to the next step of construction. Instead, you need to wait the appropriate time as outlined in the sections above.
Different Curing Methods
There are a variety of different curing methods that are frequently used during construction, and these include:
- Water cure – This is regarded as the most effective concrete curing method that is used, and will see the mix be flooded, ponded or mist sprayed. This will prevent evaporation and see the concrete harden efficiently.
- Water retaining curing – Coverings like sand, canvas and straw that are kept wet can also be used when curing. It’s vital that the material used is kept damp if this method is selected as it will help the mix retain water which is important for hardening.
- Waterproof plastic or plastic film seals – A seal can be applied to the concrete mix after it has been poured in order to resist any surface damage. While this is an effective curing technique, it can cause discolouration to occur on the surface of the concrete. With this in mind, we wouldn’t recommend this method if the concrete is needed for aesthetic purposes.
- Chemical membranes – A chemical membrane can be applied to the concrete to assist with the curing process. This can impact future adherence if you intend on placing flooring materials on the concrete after curing, so it’s always best to check with a professional before selecting this method.
Factors That Impact Concrete Drying
Different conditions and the properties of your specific mix can sometimes impact the drying process, including timescales. With this in mind, it’s important to consider your individual situation beforehand.
The main factors that should be considered are as follows:
Water is an essential element of the curing process, and without its presence, the required chemical reactions that create the important crystals cannot take place. However, it’s important to get the moisture level correct.
Too much moisture can seriously disrupt curing and cause the concrete to flake, shrink and crack. In contrast, not enough water will result in the concrete not being structurally strong or resilient.
With this in mind, we’d always advise not pouring concrete during rainy weather. Puddles and excessive water can cause your concrete to become unbalanced and may result in a sub-standard end product.
You can’t always control the weather, especially when it is as unpredictable as it can be in the UK, but it’s worth checking the forecast ahead of time. If rain begins to fall around six-eight hours after you’ve poured, you should be safe but mixes prior to this may be at risk. Alternatively, you can use covers to prevent the mix from getting wet, but it’s better to avoid pouring altogether in wet conditions.
Likewise, do not paint or apply any other wet substances to the concrete until you’re sure it has dried and cured correctly.
Temperature is another important element to consider.
Curing tends to perform better during warmer weather, but it should not be excessively hot. Extreme humidity can also impact moisture levels which, as we’ve already discussed, can be detrimental. With this in mind, it’s better to plan your projects around warmer weather if possible.
Colder weather is preferable to wet weather, but if the mercury dips below four degrees Celsius, specialist pouring techniques will be needed. Furthermore, in wintertime you should always monitor how cold it is. If it reaches -6 degrees Celsius or below, you should not pour concrete.
Types Of Mix
Depending on the type of concrete mix being used, some batches will cure faster than others. Some ‘quick drying’ products will need to be mixed and poured in a specific way, and they also do not always guarantee the same levels of durability as conventional products.
Sometimes, people will also apply accelerants to mixes but you should be wary with these products. While they can be used for smaller projects, they usually are not suitable for large-scale applications.
Leading Concrete Suppliers
At Concrete Supply UK, we’ve spent many years providing leading concrete mixes to customers nationwide.
We understand that no two projects are the same, and we always take a bespoke approach to all of our clients. This involves getting to know you and your needs, before formulating a customised mix that achieves what you need.
As well as ensuring you have the right type of mix for the job at hand, we’ll also make sure you always have the correct quantity. We’ll only pour the amount you need, so you’ll never order too much, which can be wasteful, or too little, which can slow down the project and be frustrating.
We also offer delivery options that will see us bring your mix directly to your site, and leading concrete pump hire solutions that can help you transport the batch wherever it needs to be.
To discuss your concrete needs with our friendly and knowledgeable team or to place an order, get in touch with Concrete Supply UK today.