The concrete or mortar "lid" atop the chimney is highly susceptible to impact. Hail-induced cracks in the crown allow water to seep into the internal masonry, which, during the freeze-thaw cycles common after spring hail storms, can lead to the chimney literally crumbling from the inside out.
This is the first line of defense. Hail can easily warp or crack these components, allowing moisture and debris to enter the flue. The concrete or mortar "lid" atop the chimney
Ignoring hail damage on an exterior flue in an urban setting carries significant risks. A cracked flue liner, damaged by the vibration of heavy hail or subsequent water intrusion, can leak carbon monoxide into living spaces or allow heat to escape to nearby combustible building materials. Furthermore, in high-density areas, a structurally compromised chimney poses a "falling object" risk to pedestrians and neighboring properties, creating immense liability for the owner. Conclusion Hail can easily warp or crack these components,