Does Concrete Flooring Crack?

Concrete is an incredibly tough and durably material. Increasingly, building structures are a combination of concrete and steel, adding weight and robustness to a towering building.

Quick, simple and easy to use, concrete is not a difficult material to work with. And yet, get it wrong, it can become weakened by cracks, not something you want to see creeping across your newly laid concrete floor.

Understanding why and how concrete cracks will help you understand the conditions that contribute to concrete not performing the way that it should.

Does concrete flooring crack? It can do and here are reasons why this happens…

#1 Excessive water in the mix

Concrete consists of a handful of materials all mixed together, with water providing the catalyst for fusing all these materials together. Whilst water is essential, too much of it will sap the final concrete structure of its strength.

Water makes the product easier to work with. It can be moulded into shape, pushed into smaller areas and either be angular or rounded. This is why in a domestic or industrial setting, water is added.

The reason why too much water causes cracks is because as the concrete hardens or cures, it shrinks. The process of drying is when water evaporates out of the concrete, thus shrinking it. The wetter or soupier this concrete mix is, the greater this shrinkage will be. Concrete slabs can shrink as much as half an inch per 100 foot. This shrinkage causes forces in the concrete to literally, pull the slab of concrete apart. The cracks are the end result of these forces.

In essence, a professional and reputable concrete flooring company will attempt to use as least amount of water as possible to the cement ratio.

In some ways, a company with little knowledge of concrete will only send a couple of operatives to a large concreting job. This could mean a wetter, sloppier mixture because if there are only two working with the mixture, the wetter it is, the easier it is to handle. Thus, you are looking for a company that supply many people to work on the job, using the stiffest concrete mix they can.

#2 Too-rapid drying of concrete

Trying to dry the concrete too quickly will also increase the possibility of cracking.

Within the mixture, there is a chemical reaction that turns it from its liquid state to a solid state – and this reaction requires water. This chemical reaction or hydration continues over a number of days and weeks following the concrete being poured.

There are various ways to cure concrete so that it reacts in the right way in the right situations.

#3 The wrong strength of concrete is used

If you are a baker, you will know that there are different kinds of sponge mixes. A basic sponge, containing two eggs, will be light, fluffy and soft and will not perform well as the base layer of a 10 tier cake.

Altering this mixture to include more eggs as well as other additions to the mix, create a denser cake after it has been baked, meaning it can take the compression formed by the ten tiers above it.

Although a rather simplified example, this is how concrete is too. Concrete is available in differing strength mixes all of which suit various applications. Lighter-touch concrete is perfect for when the compressive forces above and below it is not very high, such as under a garden shed or summerhouse.

Interior concrete floors will offer be part of the overall structure, and with the weight of use as well as furniture and so on, on it, a lower-strength mix may not be able to cope, leading to cracks and possibly shifting.

#4 Lack of control or expansion joints

Concrete does expand and contract, more so in situations where the concrete is outside and subject to a wide variation in temperature. In the home, this may not be so. A reputable contractor will understand how to build in the smallest of expansion or control joints into a floor so that as a complete unit it can move and ‘breathe’ without cracking.

Preventing cracking

Concrete is a mixture that takes some know-how to create and use in the right way. People often think that it is just a case of mixing various ingredients together, and throwing it down on the floor.

This is only a part of the overall equation; making sure it has a chance to naturally cure or dry, as well as using the right strength will all make for an impeccable finish on a concrete floor.