Winter storms arrive on their own schedule, and a commercial building has a lot more to protect than a house does. There is the roof, the parking lot, the loading dock, the sprinkler lines, the tenants, the stock and the people who walk through the front door every morning. When a storm hits, every one of those pieces gets tested at once. The good news is that most winter damage follows predictable patterns. Clogged drains, tired seams, frozen pipes and unplanned snow removal cause a large share of the problems…