Crown cracks leading to chimney leaks
Why it happens here
The crown is the concrete top of the chimney and it takes the full force of rain, snow and freeze-thaw. In Fernwood, the older crowns were often thin and poorly sloped, so water pools on them and finds the cracks. Once water gets in, it runs down the brick.
Our approach
We remove the failed crown, pour a new one with the correct slope away from the flue, and seal the joint where it meets the brick. Then we waterproof the stack so the next winter does not start the cycle again.