where can i find min frost depth information for tn
 

where can i find min frost depth information for tn?
for foundation design...and for that matter, a map of frost depths all over the us would be nice...does anyone know of anywhere i can find this? thx

it's old and unofficial, but "foundation engineering handbook" by winterkorn and fang has a map of selected cities' frost depth on page 489.
the values in tennessee are about 15 to 18 inches.