Centering the column

I used deck screws as shown to center the column in the bollard formwork. It should work. Whatever is used as a spacer stays embedded in the concrete, so choice of material matters. Anything thin or narrow is good because it allows easier passing of the wet concrete. It also has to be firm enough to stay in place during tamping or vibrating. The attachment point to formwork is where it will get exposed. I figure for my screws I could grind down the tips... then maybe dab some paint on it.

An interesting followup on the footing excavation -- there were no roots from the adjacent boxwood shrubs! Go figure! Now I'm confident I won't have to replace that boxwood.