Wind damage is usually caused by winds that are over 50 to 60 mph. But keep in mind that these winds can be much, much greater. Wind damage stems from tornadoes and tropical events like hurricanes, but can also occur as the result of random, everyday weather events.
Wind damage may be any damage that is caused by heavy winds, including loss of shingles or siding, roof damage, blown-out windows, fallen trees on your commercial building, and so forth. Every insurance company - and policy - will vary so it is best to review your coverage for a thorough understanding.