The weather has finally broken and NC is finally back to seasonal temperatures. We survived roughly 20 straight days with high temperatures in the Triangle area below the seasonal norm (55 on Dec. 27 was the last time we pushed above normal). The lows were in the teens for many of those long cold nights. Our official recommendation is to winterize your rain barrels just to be on the safe side. See the FAQ page at RainWaterSolutions for specifics. We do not warrant against freezing since it was not one of our design criteria when Moby came into being. It was designed as a cone shape so it would stack inside one another for ease of storage and shipping. We have learned though that a conical shape (cone like) will survive freeze/thaw cycles better than a traditional barrel shape that is fatter in the middle than on each end. When water freezes it expands – in a traditional barrel shape the pressure from the expanding ice pushes out horizontally – a stress the barrel is not designed to endure. The ending result is typically a split barrel. Being cone shaped allows the expanding ice to push upward, vertically, not pushing against the side-walls of the barrel.
We have several units in different climate zones that we torture test to ensure Moby will last for many, many years. We never winterize these test barrels to push them to the limit. I am happy to report we have never had a split barrel as a result of freezing damage. We strive to provide the best barrel on the market. Period.