Why your concrete floor is cracking – 5 expert insights you must explore
Cracks in your concrete floor can be both unsightly and concerning. They affect the appearance of your flooring and also indicate underlying structural problems. This article highlights the five primary reasons your concrete floor may be cracking. Understanding these causes is the first step towards addressing the issue and ensuring the longevity of your flooring.
Excessive Water Content in the Concrete Mix
- Concrete doesn’t require a significant amount of water to achieve optimal strength. However, most of the concrete used in residential projects has excess water added to enhance the ease of installation. This significantly compromises the concrete’s strength and is one of the primary reasons for cracking.
As concrete cures and dries, it naturally undergoes a shrinkage process due to the evaporation of excess mixing water. The more water-saturated the concrete mixture, the greater the shrinkage is. Concrete slabs can contract by as much as 1/2 inch per 100 feet. This shrinkage exerts pressure that pulls the slab apart.
Quick Drying Causes Concrete Cracking
- Rapid drying of the concrete significantly increases the risk of cracks. The chemical process of transforming concrete from liquid to solid state requires water. This chemical reaction, known as hydration, continues to occur for days and even weeks after pouring the concrete. Proper curing of the slab is essential to prevent cracking in the concrete. Concrete cures gradually and takes about 28 days to set properly. Once the concrete is poured, the steps taken in the initial days determine its strength and crack-resistant surface.
Cement, the binding agent in concrete, retains moisture to gain its full strength. Occasionally, spraying water on the poured concrete during the first week strengthens it. If the water evaporates slowly, the chances of cracks reduce. In hot and dry weather, water should be sprayed more often as the rate of evaporation increases. If the temperature is expected to drop below 50 degrees Fahrenheit during the first seven days, the concrete should be covered with an insulating blanket to prevent cold from seeping into the concrete.
Improper Concrete Strength
- It’s essential to confirm the specific strength requirements for the concrete being used, as using the wrong strength can lead to cracking. It’s advisable to consult with the supplier to determine the right concrete strength for your project.
- Another culprit behind concrete cracks is the ever-changing climate. The fluctuations in air humidity and temperature cause expansion and contraction in concrete. Excessive fluctuations in climate conditions can exert significant stress on the concrete, ultimately leading to cracks. Even the properly cured large slabs are liable to cracking due to temperature changes.
Therefore, small weak spots are created in the slab. This makes the anticipated cracks occur in these weakest spots. The weak spots created intentionally are called control joints. There are the following ways to create these joints:
- A grooving tool can be used to form the joints in wet concrete
- A concrete blade is used to cut the joints one day after pouring the concrete.
- Concrete can be susceptible to cracking due to specific ground movements. For instance, heaving, often caused by the growth of tree roots, can exert pressure on the concrete, leading to cracks. Similarly, settling can result in concrete cracking, typically occurring when water damage causes the concrete to sink.
If you have noticed cracks in your foundation, call us at (877) 727-2259. Our experts from Crack-X will assess the damage and provide necessary repairs. Crack-X is a structural repair company located in Maine and New Hampshire.