CHIMNEY LINER & RELINING IN DALLAS, TX
The liner is the continuous surface inside your flue. It contains heat and combustion gases so they never reach the surrounding masonry and framing, gives the flue the correct diameter for the appliance so it drafts properly, and protects the brick from the acidic byproducts of combustion.
In Dallas the relining question is usually about sizing rather than decay. Gas is the default fuel here — a huge share of Highland Park, Lakewood, and Preston Hollow fireplaces were converted from wood at some point, and a flue built for a wood-burning firebox is far wider than a gas appliance needs. An oversized flue lets exhaust cool and condense instead of drafting, which shows up as odour, poor performance, and corrosion. The other local driver is storms: lightning strikes and structural movement crack clay tile. Material is a code requirement — 316L stainless for anything wood-burning, aluminium acceptable for gas — installed per NFPA 211 with top plate, cap, connector, and thimble. A camera evaluation comes first; see what that costs on the inspection cost calculator.