I am pouring concrete for deck footings. I need an 18in diameter footing to carry the weight, and I will also use a 8 in diameter pier to bring it to an inch above ground. The footing must be 30 in below ground and 8 in thick. I am going to use a soil form for the footing (the hole I dig) and a sono tube for the pier.
Should I pour the footing and the concrete in one pour? I worry that the concrete in the sonotube will sink down and fill the 18 in hole while it sets, or is concrete thick enough to not worry about this? Or should I pour the footing, and then once set pour the pier. If I go this route I'll set one L shaped rebar in the footing to give support to the pier. Will an overnight set be enough?
If it matters I'll be mixing the concrete myself in an electric mixer.