Jul 28, 2018
The frost line is simply the deepest point in the ground to which ground water will freeze. It’s also referred to as the frost depth.
If you are doing any building or gardening, one thing to be mindful about the land is the frost line or frost depth. I was just reading up on geothermal tech, and you’ve got to put those pipes well below whatever your local frost line is to get the thermal benefit.
When water changes from liquid to solid, it expands 9% in volume. This resulted frost heave can be detrimental to footings and foundations. That’s why building codes specify structural footings be placed below the frost line.
Additionally, water and sewer pipes need to be buried below the frost depth.