Sorry to hear about your buddy, we loose good gearheads all too often!
Believe it or not...all the 2 post companies I talked to told me 4...yes 4...inches of high pressure concrete. I went 6...
They punch all the way through with a drill, and have expanding spider like anchors that grab. If u have it installed...they probably wont want u to do 12. The bolts are like all thread, with the anchors. Not deck lags. I was pretty surprised also!
