The ring beam drawings specify the size, number and spacing of the reinforcing bars and ligatures to be used as well as the MPA rating for the concrete. Ring beams should be as level as possible and have no more than +/- 1/16” over any 5’0” (+/- 2mm over any 2m) of the circumference at the tank wall position and +/- 1/8” (+/- 4mm) over the entire ring beam. A survey chart will need to be completed and returned to your local installer for approval before the construction is started.