Chimney crown repair deals with the concrete slab that caps the top of a masonry chimney. The crown should slope away from the flue on every side, overhang the brick by about two inches, and have a drip edge cut underneath so water falls clear of the chimney face.
Most crowns we see were never built that way. A lot of them are a thin layer of mortar troweled flat over the top course of brick. Mortar is not concrete. It shrinks, cracks, and lets water straight down into the chimney, where freeze-thaw cycles push the brick apart from the inside. That is often the source of a leak that homeowners blame on the flashing.
For hairline cracks we clean the crown and apply a flexible crown sealant made for masonry. For a crown that is broken, flat, or pulling away from the flue tile, our crew tears it off and forms a new one with a bagged crown mix, a proper slope and a bond break around the flue so the tile can expand without cracking the new slab.
A crown repair is a good time to add chimney cap installation and to look at the mortar below with chimney tuckpointing. Call (833) 583-1301 to book chimney leak repair from the top down.
