esshup, You bring up a good point. Contractors have told me that a clay bottom would support such a structure if the stanchions are down deep enough to reach the compressed clay. I have seen some very hard blue clay come out of the pond when it was being dug. I could opt for PT 6"x6" but that would be more difficult to get more depth. or I might be able to drive in another set of four for additional support but im still concerned about the proper depth to resist ice lift. Maybe 8 4"x4", Who knows?
