What is the term for the greatest depth to which the ground may be expected to freeze?

The term "frost line" refers to the maximum depth at which the ground is expected to freeze during the coldest part of the year. Understanding the frost line is crucial in construction and masonry because it influences the depth at which foundations and footings must be placed to prevent damage due to freezing and thawing cycles. If the footings are not placed below this line, the ground's expansion during freezing can lead to structural issues, such as cracked foundations or shifted structures. Ensuring that building components are properly situated below the frost line is a standard practice in masonry to maintain the integrity and longevity of structures.

Other terms like "freezing depth," "ground frost limit," and "permafrost zone" do not specifically refer to the depth at which freezing ground conditions affect construction practices in the same way as the frost line does. Each of these terms has different contextual implications; for instance, the permafrost zone refers to areas of the ground that remain permanently frozen, which is a different concept altogether.