Warning: stopped guessing deck footings with a post hole digger last spring
Used to just dig down about 2 feet and dump a bag of concrete in, which is why my first 12x16 deck at the house sagged 3 inches by fall. Now I rent an auger for $80 a day and go down to my local frost line, so what depth do you all dig to in cold country?
Digging down about 2 feet and dumping a bag of concrete is exactly how I did my first shed pad too, and it heaved so bad the door wouldn't shut by spring. I'm in Minnesota so our frost line runs about 42 inches, which means renting that auger and going down 4 feet is just the price of doing it right. A buddy of mine swears 36 inches is plenty but I watched his fence posts pop right out of the ground after one hard winter. What part of the country are you in?