How Does It Take for a Concrete Floor to Dry?

If you have opted for a concrete floor, whether that is in your home, business or in another building, you will no doubt be excited about seeing the finished product. But laying a concrete floor requires patience as the drying or curing process does not happen overnight.

With this in mind, we look at the mixing, laying and drying process of concrete.

How is concrete made?

A concrete mix consists of only a few ingredients and when water is added, there is a chemical reaction. This continues to react during the laying process but concrete can ‘go off’ quickly, become sticker and more difficult to work with.

Many people assume that because of this quickness in changing from liquid to sludge, that it only takes a matter of hours for the concrete floor to dry. However, this is not quite the case.

The water needs to evaporate slowly out of the concrete, leaving a tough, robust and durable floor surface that can now be treated, sealed and buffed. Rushing this drying process by attempting to artificially dry the concrete out or using too thick a moisture can lead to the floor being compromised. In other words, your concrete floor will crack.

Getting the right mix is just as important as allowing the floor to dry naturally;

The mix was too wet

Excessive water in the concrete mix can cause the floor to crack as it dries out. In fact, concrete doesn’t need a lot of water in order for it to reach its maximum strength.

The reason why some installers or builders will add more water to a concrete mix is to make it more pliable. This makes it easier to handle and lay on the floor but this excess water zaps the floor its strength.

Just like other components or materials that contain water, as it dries and the water evaporates, the concrete shrinks. The wetter the concrete mix, the greater this shrinkage will be. And so the number one issue in what affects the drying time and quality of the final product is excess water in the mix.

Drying it too rapidly

With the excitement and desire to have the floor finally finish can mean we can be too impatient and attempt to dry the concrete floor too quickly.

We see concrete being mixed all the time and assume that once laid and the top layer looks dry, that the rest of the structure is hard enough to start sealing and treating. The chemical process that happens in the concrete between the water and the mix is a process that occurs for hours or even days if the floor is a vast expanse, after the concrete has been laid.

But if you try to dry out the floor out too quickly, it means this chemical reaction doesn’t get to complete the full cycle, possibly leaving parts of the floor vulnerable.

What can also slow drying time to a snail’s pace is when the weather is cold. Clearly, an ambient heat of a warm summer’s day is far more favourable for drying a concrete floor than placing heaters or humidifiers near a newly laid floor.

Not using the right strength concrete

There are other reasons why it can take longer for the concrete floor to dry and why this can spell disaster for you.

Using the wrong strength mix, for example, can mean that even with the correct drying process, the floor will crack and move.

Lack of control joints

It is also important to note that over vast expanses of floor, the contractor will look to create control joints. This allows the drying process to occur without cracking and when this does need to happen, the concrete is able to breathe at the control joints, meaning no cracks become visible on the main floor.

Letting the concrete dry ‘naturally’

It may seem like a slow and painful process and one that you want to hurry up! But to get the right finish, you need to ensuring that the concrete is allowed to dry as naturally and slowly as possible.

As well as the water content affecting the drying time, the thickness of the concrete will be affected too. Internal concrete floors might not be as thick or as deep as you think and when this is the case, your concrete floor could be fully serviceable and ready to use in as little as 28 days.

Are you considering a concrete floor? Ask us about drying times!