The plastic sheeting is only for winter wear..and it lasts all winter long and beyond. Some is being used for the second winter. Snow load, I'm not sure...we don't get more than 3-5 ft of snow here and that is now pretty rare. Used to be we'd get that every winter and some areas of the state still get that and more each winter. The arched design would tend to withstand a heavy burden more than a flatter roof, with most of the snow falling off the sides and only a minimal cap remaining on top, which could be easily knocked off, I'm thinking. The cattle panels have good tensile strength and would no doubt hold more than PVC arches would.
For an 8x10 coop, the cost is so minimal compared to other forms of construction and the prices of traditional coops. It also has the advantage of being easily disassembled or easily moved as is to a new location, it has the open air design that is desirable for our warming climates and it has expansion capabilities.
