Chimney liners & relining in Philadelphia

What a liner does

HomeGuide describes a liner as a clay, ceramic, cement or metal conduit inside the chimney that channels gas, smoke and combustion products outside, and protects the masonry from heat and corrosion. It also notes that a liner “prevents carbon monoxide from entering the home.”

Signs you may need relining

• An inspection finds cracked or missing clay tiles, or corrosion in a metal liner
• Broken clay pieces in the firebox or at the base of the flue
• Condensation, drafting, soot or creosote problems, or an unusual smell
• You’re replacing a furnace, boiler or water heater and the new appliance needs a different liner

That list follows HomeGuide’s signs of a failing liner. Only an inspection, usually Level II with a camera, can tell you the liner’s actual condition.

Liner types

• Stainless steel is the most common choice. HomeGuide says it works with all fuel types and lasts 15–20 years if well maintained; Angi says 15–20 years.
• Aluminum is cheaper but only suitable for medium-heat gas appliances, and HomeGuide says it rusts more easily and lasts around 5 years.
• Clay tile and cast-in-place liners can last up to about 50 years, but clay is labor-intensive to replace and cast-in-place is the priciest option.

Permits

Philadelphia issues Mechanical Permits for work regulated by the Mechanical and Fuel Gas Codes, and says a licensed contractor must do the work. Ask your contractor whether your specific job needs one and who pulls it. For one- and two-family homes, L&I lists $69 per heating apparatus connected to a flue or chimney and a $100 filing fee that is credited toward the final permit fee. More on the rules.

Watch out for

HomeGuide warns about inspectors who claim a chimney is dangerous and needs full relining when it may not. If you’re told you need a new liner, ask to see the camera footage and get a second quote.