Cracks in concrete can be a sign of structural damage, but it's not always easy to tell the difference between a harmless crack and one that requires attention. Fortunately, there are a few indicators that can help you determine the severity of a crack in concrete. If a crack is active and continues to widen, if it allows moisture penetration, retains dirt, or is located in a high-visibility area, it is likely to be a structural crack. Structural cracks can have an impact on the strength and durability of the concrete structure.
Structural cracks are usually easy to identify. They can take many shapes and sizes, such as horizontal, vertical, diagonal, or ladder-like in foundation blocks. Concrete is a strong material, but it has its limits. Placing too much weight on a concrete slab can cause cracking.
When you hear that a concrete mix has a strength of 2000, 3000, 4000 or more than 5000 PSI (pounds per square inch), it refers to the amount of pressure needed to crush the concrete slab. Structural cracks usually have some telltale signs. These cracks can be horizontal, vertical, diagonal or ladder-like. There may be cracks in the foundation wall, beams or foundation slabs.
Structural cracks often extend to the upper floors of the house. It's important to consult with a foundation repair expert to diagnose the situation, but structural cracks are generally more than three millimeters wide. A simple way to monitor for cracks is to mark the ends with a pencil and write down the date. Check periodically to see if the cracks have grown beyond the pencil marks - this could indicate a worsening structural problem. Proper site preparation, quality mixing and good concrete finishing practices can help minimize cracking and create a more aesthetically pleasing concrete project.
Crusting cracking usually occurs during the concrete stamping process - a way of adding texture or pattern to concrete surfaces. Since concrete cannot shrink around corners, stress will cause it to crack from that point.
