Frost line depth in Ketchikan Gateway Borough, AK

How deep the ground freezes in Ketchikan Gateway Borough, AK

12 in. Dig to 12 in, the 12 in code minimum. Nearest NOAA station: Beaver Falls, 24 mi.

Your building department sets the legal frost line depth (IRC Table R301.2(1)); footings must go below it (R403.1.4.1). Call them before you dig.

12 in minimum · Method