Frost Line

Building codes require footings to sit below the frost line for a simple reason: soil that freezes above a footing doesn't move the footing, but soil that freezes underneath or beside a shallow one can lift it as the water in the ground turns to ice and expands. A footing poured above the frost line is sitting in the exact layer of ground that moves every winter, which is why frost depth is one of the first things a mason checks before digging.

Frost depth isn't the same everywhere, it shifts with local climate, elevation, and soil type, and it can vary from one site to another across Carroll, Grayson, and the surrounding counties. Given how hard the freeze-thaw cycle runs in the foothills all winter, we check local frost depth requirements before pouring any footing rather than guessing at a standard number.