The concrete worked! By this time last year we were repairing the first wall collapse of the season. The rain, snow, and general wet of winter had caused the tires to weaken and collapse. Not just once but twice. It took us until halfway through he summer to be back to where we were before the winter hit. It was a terrible setback.
This year the only issues we had was some settling of the tires that made parts of the loft sink and two sections of the loft wall fell. It took us two days to put it all back together. We even added framing for a door to the loft so we can build an upper deck that is just for us (and also so we can bring our furniture in). We are very excited!! Let the building begin!!!