What Causes an Uneven Driveway?

An uneven driveway that is cracked or even sinking can be caused by a number of issues. The most common problems, however, are in the soil or in the concrete itself. Issues like erosion, washout, and soil movement, for example, can lead to damage to even the strongest of concrete surfaces, but those which are already damaged or flawed are, of course, the most vulnerable.  

Soil Washout and Erosion   

Soil washout and erosion are incredibly damaging and can cause problems for the main structure of your home as well as more exposed areas like your driveway. This issue primarily affects homes that sit on weak or unhealthy soil, however. Sandy and loamy soils, for example, are very light and can be prone to washout and erosion in extreme weather.  

As the soil washes or blows away, it gets progressively less healthy and therefore erodes at an accelerated rate. This undermines the structure and stability of your soil by leaving gaps between the underside of the concrete and the soil. Over time, this will cause the surface to crack and sink into the void left behind. As a result, you will be left with an uneven driveway. This can also cause settlement and subsidence in your foundation, however, or even lead to your property’s foundation shifting.  

Poorly Mixed Concrete  

Concrete is a durable substance that can be tailored to suit any situation. This means that it is versatile, but it can also cause issues when the people mixing the concrete make errors. The presence of certain minerals, for example, can cause staining, while too much or too little water can make it weak and prone to cosmetic damage. Issues like spalling, flaking, pitting, and staining may seem benign, but they can be signs of deeper problems, or even devolve into larger issues with time and exposure to the elements. Of course, if the concrete is defective, the issues will be much worse. 

In the most extreme cases, using the wrong aggregate can make concrete weak, crumbly, or even prevent it from curing properly. Likewise, the use of improper laying methods can cause many issues for a property by undermining the strength of the structure as a whole. Hard troweling (the process of troweling the concrete to compact it after it has begun to set) may cause real issues. The same holds true for improper or inadequate curing. Whatever the defect, however, it all ends the same way: with damage and instability. This can manifest as cracking, sinking, or general deterioration.