My uncle swore by using a 3-inch auger for all post holes, even in clay
He said it was faster and the concrete would hold fine, so I tried it on a job in Springfield last month. Two weeks later, a whole section of the fence was leaning after a heavy rain because the posts just didn't have enough grip. What size do you guys actually use for clay soil?
Ever try to save time and go shallow? My fence posts last year looked like a drunk guy put them in after a 4-inch hole in wet clay. Whole section leaned like it was trying to escape.