The frost line in Indiana is the depth that groundwater in the soil freezes during the winter. The frost line depth in Indiana ranges from 30 to 60 inches, with 30 inches being the frost line depth in the southern part of the state and 60 inches in the north.
Depending on the local agency, the frost line might go under the names frost depth or freezing depth. It is important for homeowners, contractors and other service professionals to know the frost line. This is due to the fact that water lines, decking supports and much more need to extend below the frost line to be up to code.
This is especially important for water lines. When the ground freezes, water lines will freeze too. Since the ice expands, the water line could break or crack, causing a headache for home and business owners.
In Indiana, the frost line varies depending on location and elevation. This is why it is important to have a frost line map available, which shows the depth of the frost line across the state. The northern half of the state has a frost depth of 60 inches, with a small portion of that area having a 48 to 54-inch depth. In the southern part of Indiana, there is a much wider dispersal of depths ranging from 30 inches at the very southern borders to 54 inches near the center of the state.