What should be the depth of the bottom of the deck footing in relation to the frost line?

The bottom of the deck footing should be located below the frost line to prevent damage caused by freeze-thaw cycles. When footings are placed above the frost line, they are at risk of heaving due to the expansion of soil when it freezes. This can lead to structural issues for the deck as the footing shifts or settles over time. By installing the footing below the frost line, builders ensure that the soil remains stable and unaffected by freezing temperatures, providing a solid base for the deck that maintains its integrity over the seasons. This is a crucial consideration in regions where frost is a factor, making the correct depth essential for long-term durability and safety of the structure.