Why Are My Concrete Slabs Stained and Flaking?

Concrete is a fairly durable material, but that does not make it infallible. There are a few things that can cause staining, discoloration, and general cosmetic damage to concrete surfaces around your home. This cosmetic damage can also be a sign of more serious problems on the way, but this is not always the case. 

Defects 

Defects in the concrete itself cause a huge number of issues for any structure. They can also originate in many places. In fact, issues with the fundamental makeup of the concrete can go all the way back to the cement mixing process. After all, concrete is really just a mix of water, sand, and aggregate. Having too much water, sand, or even a certain kind of mineral in the aggregate can cause cosmetic issues to form. Likewise, concrete that is disturbed after it has started to set or that is improperly cured is far weaker. 

This can lead to many cosmetic defects and issues, but the most common are spalling, flaking, pitting, and staining. Spalling is a process by which large, ovular chunks of concrete break away from the rest of the surface. It’s also the issue most likely to cause structural damage in the long run. By and large, however, these issues are unlikely to result in more serious problems, like sinking. 

Climate 

The weather and climate around your home are very important and can have a huge impact on the health of concrete surfaces. In areas like Missouri, where the summers can be humid but the winters are fairly harsh, concrete will start to suffer fairly quickly, especially when there is a particularly hard winter or a changeable spring season. 

Repeated freeze/thaw cycles are by far the most damaging influence on a concrete slab. This is largely because of the porous nature of concrete. It absorbs water that expands during a sudden cold snap and shrinks when it thaws. Most concrete can cope with this happening once or twice, but when it happens a few times in rapid succession, the chances of damage increase dramatically.