We had to replace some of the columns in our building because old roof leaks had damaged them. But we had to replace them with stronger ones, because our new super-insulated building will lose less heat through the roof. This means the snow will not melt as quickly and will be deeper and heavier than before, so our roof needs to be able to handle that load. We also want to make sure that when we add solar panels in the future, our roof can support those too.
The old cement filled columns have been successfully removed, and shiny new columns have taken their place. Each column weighed about 2 tons and in addition to being cement filled, also contained another column within.
The new columns are hollow, but very durable steel. Although they will soon blend into the landscape once the store is filled with racking and products, their presence is symbolic of how quickly the interior of the building is progressing as construction continues.
Article source: http://restoreonline.org/expansion/?p=489