Crown damage from freeze-thaw cycles
Why it happens here
Old West Lawrence winters drop below freezing for weeks, and water sitting on a flat or cracked crown expands as it freezes. That opens the crack wider each year until water runs straight into the flue. Most of the leak calls we get in the Historic District start here.
Our approach
We pour a new crown mix with a proper slope and overhang so water sheds instead of pooling. We also add a bond break between the crown and the brick so the two can move independently. Then we seal the top courses with waterproofing sealant.