So I am pouring some footings for a deck I am building and my current plan is to dig a hole that is 18" wide and 18" deep. I'm then going to suspend a sonotube about 6 inches above the bottom (using a scrap wood frame).
My idea is to pour concrete in through the sonotube and have it splay out at the bottom, but once the concrete fills the bottom of the hole up to the sonotube, that it stop filling the hole.
I'm not sure if that was confusing or not, so I drew a crude picture. The blue line is as high as I want the concrete to go in the hole. The red "X"s should be empty space in the hole and the sonotube in the center should be filled with concrete.
My question: If i take this approach will the concrete fill in as I have drawn in the picture, or will the concrete in the sonotube keep pouring out and fill the hole all the way to the top?