Crown damage from freeze-thaw cycles
Why it happens here
Oread winters swing above and below freezing repeatedly. Water seeps into small cracks in the crown, freezes, and expands. Within a season or two, a hairline crack becomes a broken crown that leaks into the chimney chase.
Our approach
We replace damaged crowns with chimney crown mix or apply a flexible crown coating for minor cracks. Then we waterproof the brick to reduce water absorption. Most crown repairs are done in one day and stop the leak immediately.