Water is easily the biggest threat for chimneys of all types, whether they’re used often, rarely, or not at all. Year after year, your chimney is bombarded by wind and weather – including rain, sleet, and, depending on where you live, even snow.
All that moisture can wear down masonry and metal chimneys over time, especially if they’re not properly protected against the elements.
So, what can you do to provide a line of defense for your chimney?
Have your crown checked for proper slope, drip edge, material, and thickness. You’ll need to have your crown inspected annually, and if any cracks appear, make sure they’re repaired while they’re still small.
-CSIA.org