Negative soil sloping or grading is a condition which occurs when you have water flowing toward your house, instead of away from it. This by itself will cause your foundation to fail prematurely. Even brand new homes will suffer from this issue if it is not resolved. The increased water funneling toward your house will increase the hydrostatic pressure on the foundation walls which will cause them to leak, crack, shear, and even decompose over long periods of time. Flooding will also become an issue which will lead to conditions for mold and mildew and rotting to take place.
What is the cause of a negative soil grade or slope? Simply put, the soil around your foundation was not properly graded and engineered during construction. It more than likely was poorly compacted as well. Depending on the amount of clay, sand, and organic matter in your soil, it’s unique geologic composition can present a variety of problematic reactions to an extended period of wet, dry, hot or cold conditions. When soil stays too dry, it shrinks and creates voids where a foundation will settle. When soil stays too wet, it gets soft and cannot bear the heavy loads and a foundation will sink. When soil freezes, it will expand and heave the foundation upwards. All of these soil conditions put pressure on a foundation which then causes damage to it and the structure above.