Cracked chimney crown leaking into the attic
Why it happens here
The crown is a thin concrete cap on top of the chimney, and it takes the full force of freeze-thaw cycles. Water sits in a hairline crack, freezes overnight, and widens it. By the end of winter, the crack runs through the crown and water drips straight down the flue.
Our approach
We chip out the failed crown mix, rebuild the crown with a proper slope and an overhang, and seal it. Then we waterproof the brick below it. A rebuilt crown lasts 15 to 20 years in this climate.