How Does Soil Settlement and Sinking Cause Concrete Floor Cracks?

When you first notice concrete floor cracks, you might wonder how soil settlement and sinking could possibly cause problems with your concrete. There are many ways this can happen, but there are two main elements of concrete that tend to create this response to soil settlement.  

• Concrete Doesn’t Bend  

The first thing to remember is that concrete just doesn’t bend. Whenever concrete appears to be bending, what’s really happening is that there are many little cracks opening along the surface of the concrete. These little cracks may make it look like the concrete is bending, but because concrete is such a rigid material, it’s actually just cracking.  

Whenever concrete is in a situation where there’s an uneven amount of pressure on one side of the concrete, you’re likely to start seeing cracking problems. Over a long period of time or when the concrete starts having to handle a significant amount of weight, you’re going to see more obvious cracks in the concrete.  

• Concrete Is Very Heavy  

It’s also important to remember that on average, concrete is extremely heavy. A solid slab of concrete will weigh 150 pounds per cubic foot, which is a gigantic amount of weight. Your concrete almost certainly isn’t going to be a foot deep, but that means a four-inch slab across three feet will still weigh 150 pounds, and your concrete probably weighs even more than that.  

The heaviness of the concrete adds to the issues that can arise when concrete tries to bend. If the concrete were lighter, it might not end up with cracks so easily, but because of the weight of the concrete, it weighs on itself, causing it to crack a bit more easily. When the soil starts settling, especially if it starts settling unevenly, that weight is going to inevitably end up causing cracks.