A flue liner is the protective lining inside the flue, most often clay tile, stainless steel, or cast-in-place material, that contains heat and combustion byproducts and shields the surrounding brick and mortar.
Clay tile liners come in stacked sections with a mortar joint between each one, and over decades that mortar can crack or a tile can shift out of alignment. Metal liners get installed as a continuous sleeve, often when a chimney is being relined rather than rebuilt, and cast-in-place liners get poured or troweled in to fill out an irregular or oversized flue. Either way, the liner's job is the same: keep creosote, heat, and moisture away from direct contact with the chimney's structural brick.
A cracked or missing section of flue liner lets heat and moisture reach brick and mortar that were never built to take that kind of direct exposure, and a Blue Ridge winter makes that damage compound fast. A damaged liner can also let combustion gases leak into spaces around the chimney instead of venting cleanly outside, which is a safety concern on top of the structural one. We inspect the liner as part of any chimney repair before deciding whether a chimney needs relining, a rebuild, or just crown and mortar work.
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.
