Chimney Liner Repair & Installation

Types of Chimney Liners

• Clay tile liners — the traditional liner found in most older Portland-area homes, made of individual fired-clay sections stacked inside the chimney. Durable but rigid, and prone to cracking from thermal shock or a chimney fire.
• Stainless steel liners — flexible or rigid metal liner, commonly installed when relining an existing masonry chimney, switching fuel types, or correcting an oversized flue. Well-suited to wood, gas, and oil appliances alike, and the most common choice for repair work.
• Cast-in-place liners — a cementitious liner material poured or pumped into the chimney to form a new smooth-walled liner. Often used when a clay liner has failed extensively and both structural reinforcement and relining are needed at once.

Signs Your Liner Needs Attention

• Pieces of tile liner (small ceramic-looking chunks) found in the firebox or on the smoke shelf
• Visible cracks or gaps during a Level 2 video-scan inspection
• White staining (efflorescence) on exterior brick, indicating moisture is passing through the chimney structure
• Higher-than-expected heating bills, which can indicate heat escaping through gaps rather than venting properly
• Visible daylight or gaps between liner sections

Why a Damaged Liner Is a Real Fire Risk

The liner's job is to contain heat and combustion byproducts and vent them safely above the roofline, keeping both at a safe distance from the wood framing and other combustible materials that make up the rest of the chimney chase and surrounding structure. A cracked or gapped liner lets heat transfer directly to those combustibles, and it's one of the mechanisms by which a contained chimney fire can spread into the house structure itself. An unlined or severely damaged flue is not something to defer — we'll flag it as a priority repair, not a someday item.

Sizing Matters as Much as Material

An oversized flue (common when relining after switching from wood to a smaller gas appliance without resizing) drafts poorly and lets flue gases cool too quickly, increasing creosote condensation and moisture problems. We size liners to the appliance actually connected, following manufacturer and code specifications, not just to whatever was there before.