Cracked chimney crowns from freeze-thaw cycles
Why it happens here
North Shore gets repeated freeze-thaw cycles through the winter, and the crown is the most exposed part of the chimney. Water gets into small cracks, freezes, and expands, which makes the cracks bigger each season. After a few winters, the crown can fail completely.
Our approach
We rebuild crowns with chimney crown mix, slope them properly, and seal the edges. We also recommend waterproofing the brick at the same time. A properly built crown should last 15 to 20 years in this climate.