I was a residential cribbed for 12 years and know what your talking about... cleaning up a blowout is alot of fun...lolI could see building in the 1200 range with plywood, but only if it is shallow. While concrete is heavier when wet... I have had to pour some crazy stuff with concrete and boy does it ever bend the heck out if plywood forms. I could see long term plywood tanks having issues if not built well.
Oh boy.... sure is... hahahahaa that makes for a VERY long dayI was a residential cribbed for 12 years and know what your talking about... cleaning up a blowout is alot of fun...lol