September 10, 2026

Is a Chimney Liner Required in New York

In New York, a chimney liner is required any time a flue carries combustion gases, and a damaged or missing liner is a safety defect even in an older home. Codes follow NFPA 211 and the model residential code, and both expect a continuous, intact liner sized for the appliance connected to it.

Damaged chimney flue liner needing replacement

When a Liner Is Required or Strongly Recommended

A new gas, oil or wood-burning appliance is connected to an old flue
A wood stove or insert is installed in a fireplace
You converted from oil to gas, which changes flue gas temperature and moisture
An inspection finds cracked tiles, missing mortar joints or gaps
The existing flue is unlined, common in older New York homes

Types of Chimney Liners

Stainless Steel

The standard for relining. Flexible or rigid stainless steel is insulated and rated for all fuels, often with a lifetime warranty.

Clay Tile

Traditional in masonry chimneys. Durable but brittle, and thermal shock can crack individual tiles.

Cast-in-Place

A cement-like material poured around a form to create a seamless liner, used when the flue is badly deteriorated.

What a Liner Does

It contains heat and gases, protects the masonry from corrosive condensation, and prevents carbon monoxide from leaking through cracks into living spaces. It also gives the flue the right diameter, which improves draft.

Cost and Timing

Relining costs vary with flue height, shape and liner type. Most installs take a day, and a camera inspection beforehand gives you a firm quote instead of a guess.

Not sure what your chimney has Ask a certified technician to run a camera through it. A Level 2 inspection gives you a recorded view of every foot of the flue.

Code and Standards Behind Liner Requirements

Chimney liner rules come from national fire codes adopted into New York building practice. NFPA 211 expects flues to be lined, continuous and free of gaps, and appliance manufacturers add their own venting requirements. When a mortgage lender, insurer or home inspector sees an unlined flue, they typically ask for a repair or a relining quote.

How to Know Whether Your Chimney Has a Liner

Look up the flue with a flashlight: clay tiles appear as square or round sections about two feet long
Stainless steel liners look like a smooth metal tube or a ribbed flexible pipe
Older homes built before the mid twentieth century may have brick only, with no liner at all
A camera inspection confirms the type and condition

Common Liner Problems

Cracked or spalled clay tiles from thermal shock
Missing mortar between tiles
Corrosion in metal liners that were not rated for the fuel
Wrong size for the appliance, causing poor draft
Collapsed sections after a chimney fire

Matching Liner to Fuel

Gas appliances need a liner sized for low-temperature, moisture-heavy exhaust, while wood stoves need a liner rated for high heat and insulated to reduce creosote. High efficiency furnaces often need special venting. Always choose a liner that matches the appliance manual.