A chimney crown is the sloped concrete or mortar cap poured across the very top of a masonry chimney that sheds rainwater away from the flue and the brick stack below.
The crown covers the entire top of the chimney except the flue opening itself, and a properly built one slopes away from the flue with a drip edge that overhangs the brick by an inch or two. That overhang keeps water running off the crown from washing straight down the face of the chimney. Crowns are usually poured separately from the flue liner so the two materials can expand and contract independently without cracking each other apart.
Because the crown sits fully exposed at the top of the stack, it takes the worst of the weather up here. Water finds any hairline crack, soaks in, freezes overnight, and expands, and that freeze-thaw cycle turns a small crack into a chunk of missing crown in a season or two. Once the crown fails, water gets straight into the brick and flue liner underneath, which is why we check crown condition on every chimney repair call.
More masonry vocabulary from the glossary.
The services where this term comes up.
Chelo's Brick & Stone serves Hillsville, Galax, Wytheville, Fancy Gap, and Independence, VA. Call for a straight answer and a free on-site estimate.
