The crown of a masonry chimney is the upper horizontal surface covering the termination of the chimney body as the flue extends past a few inches. The purpose of the crown is to keep water out of the chimney. In the south, crowns are typically constructed with common mortar, which usually shrinks & cracks within the first few days and worsens with time. The “100-year” crown is formed and crafted with concrete, which will last a lifetime.
Sometimes all you need is a top down damper replacement to repair your chimney.