i dont know whho cares
Most concrete foundations are buried 4' to get below the frost line which is around 3'.
42" per adopted code
48inches
4 feet
The frost depth level below area's usually not less than 800 mm .
The frost line depth for the Ottawa-Montreal area ranges from 1.4m to 1.5m below surface elevation.
Frost line depth is measured from grade (or lowest surface soil level pursuant to the foundation).
12 inches
32"
The frost line in the city of Chicago is thought to be 36 inches. The average Chicago winter does not exceed the 36 inch frost line, but extremely cold winters can.
no Frost
In western Pennsylvania the frost line falls at 36", when installing underground waterlines 42" is perfered.
no Frost
frost line in pa is 42 inches
The frost line in Salt lake city is 30 in. I would assume that that is average for most of the state.
24in
42 inches
one metre
42"
3ft