Why Does Concrete Crack?

There may be varying reasons as to why concrete is beginning to show cracks in various area’s. We will list some possible reasons as to why you are noticing cracks, however, it is important to understand that cracks in concrete surfaces does not automatically mean the surface or structure is beginning to decay or crumble. There are varying reasons as to why such things happen to concrete, just know it is not unheard of to even see cracks in concrete hours after it has been poured.

One of the many thoughts floating through the mind of someone who has a concrete surface that is beginning to crack is, “Who installed this? They did a horrible job!” Trust me when I tell you, just because you are experiencing those cracks does not necessarily mean it was the contractors fault when they installed the concrete.

So let’s take a look at some of the more common and possible reasons as to why concrete cracks.

Reason #1…There is excess water in the concrete mix.

Concrete does not require a lot of water in order for it to reach its maximum strength. However, the more water you add to the mix the easier it becomes to install. As the concrete hardens and the water evaporates, the concrete begins to shrink (this is the normal process) and thus, cracks can begin to form as the concrete dries and settles.

Reason #2… Rapid drying.

Rapid drying can be another cause for concrete beginning to show cracks. This can be caused because of a lack in water that the concrete needs during the process of drying. Adequately curing the slab will greatly help decrease the possibility of cracking during the drying phase.

Reason #3… Improper strength used for the job.

Concrete is available in a variety of strengths and should be checked prior to pouring that the correct strength is being used for the job.

Reason #4… Lack of control joints.

Control joints help you control where the concrete will crack. A lack of control joints means you’ll have cracking in places you didn’t expect or want.

So those are some of the possible reasons as to why concrete may be cracking and they are all reasons and potential issues with how the concrete was mixed, poured, and set. Just know, those are four of a wide range of possibilities.

The honest truth is that when concrete begins to crack the customer ALWAYS wants to blame the contractor. However, know that your contractor has your best in mind when they are building and creating anything you’ve hired them for.

Remember Reason #4 above? Control joints are used to ensure the finished product is strong, effective, and that it will stand the test of time. Control joints are used to help the concrete remain strong and to hold up to harsh conditions. The control joints work to ensure that cracks happen. That’s right, you want your concrete to crack! However, you want to make sure your concrete cracks in the right places at the control joints! And any contractor worth their weight in gold will know how to accurately and cost-effectively install your concrete making sure it cracks in the right places.