I'm getting ready to start a self-contracted pool build. I've done my homework and understand the gunite shell and basic pool plumbing. Most bond beams are 12" x 12" with 4 x 1/2 rebar rods and the shell is usually minimum 6" thick with 3/8" rebar on max 9" centers. I do notice though, from time to time, that people mention having thicker (taller) bond beams, say 18" on pools that are flush with the surround, not raised.

Is there an advantage to beefing up the bond beam a bit? Say 12" thick by 18" tall? Any disadvantages? I will basically be able to dictate to the rebar/gunite crew what I want, and with the extra money I'm saving by skipping the PB, a few upgrades or mods don't hurt the budget much.