Quite true. One windy day in Maryland, I came home from work to find the deck umbrella in the front yard. The wind had lifted it up like a sail, removed it from its stand and sent it flying over my roof.
One of my product lines is umbrellas…market style to the large cantilever types. I sell mostly the commercial grade. Even so, people do not realise that the awning grade fabric on their umbrella acts just like a sail on a boat! People put up a 10 foot by 10 foot or larger shade and walk away…never monitoring wind throughout the day. In gusty high wind, If they install with a fixed mount the only thing damaged is the umbrella. If they opted for freestanding weighting the umbrella with bases… anything can happen. Liability falls to the end user.
Surprised at how many will not listen to me and fix mount these shades.