The Caissons are rolling along

Our engineer called for 18" caissons for our porch supports, so I hire a drilling rig for an hour to bore 9 holes.  The 18" diameter is a bit overkill for porch caissons - 12" would certainly be just fine.  There aren't too many alternatives to getting a big drilling rig when the holes are so wide.  We drill down below frost line and the rig makes nice, clean, perfectly vertical holes.

I pickup some cardboard tubes to cut and place over the tops of the holes.  This will create forms for the concrete above grade.

Some string lines help locate and level the cardboard forms.  I tie #4 (1/2 inch) rebar into long rectangles to place in the holes.

Everything is set for the concrete delivery the next morning . . .