Howdy. We are in the process of putting sona tubes and a new beam under our front porch as it is rotting its way right off our house. The outer edge of the deck has sunk 2.5" over the many decades it has been around and there is a distinct drop in the second story floor. I want to pour sona tubes, place a new beam and slowly and evenly elevate the deck that 2.5" it has dropped. Is there an adjustable 6x6 plate I can place in the sona tube when we pour that will allow for this much upward adjustment? Or, can I just partly bury a telepost in the sona tube? Any ideas and names of products would be greatly appreciated.