What a liner does and why it fails

The liner keeps heat and combustion gases inside the flue and away from the framing. When it cracks, both start reaching the wood, and that is a fire and carbon monoxide risk.

Most older LA chimneys are lined with clay tile. Clay is brittle. It splits from the heat of a chimney fire and from ground movement, and the 1994 Northridge quake cracked liners across the basin.

Once a tile is cracked, the flue leaks. Gases find the gap, heat reaches the masonry and the wood behind it, and creosote collects in the break. A cracked liner is the reason we tell people to stop using a fireplace until it is fixed.

Some homes have no liner at all, just bare brick. Those were never safe to burn in and need lining before they are used.

304 or 316, and why it matters

304 stainless suits an open wood fireplace. 316 is the alloy for gas and high efficiency appliances, because their exhaust is more corrosive.

We run a flexible or rigid stainless liner the full length of the flue, sized to the appliance it serves. Too big and it will not draw, too small and it chokes. NFPA 211 sets the sizing and the clearances, and we build to it.

A stainless liner insulated and installed right lasts decades and usually carries a lifetime warranty. It also brings an old chimney back to a safe, code standard without rebuilding the masonry.

A Level II camera inspection shows the liner condition.

How a reline goes

1. Camera the flue

   We run a camera the full length to confirm the tile is cracked and to measure for the new liner.

2. Size the liner

   The liner is sized to the fireplace or appliance and the alloy chosen for wood or gas, following NFPA 211.

3. Run and insulate

   The stainless liner goes down the flue and is insulated, so it holds temperature and draws cleanly.

4. Top and connect

   A new top plate and cap seal the liner at the crown, and it is connected properly to the appliance below.

Relining an old LA chimney

Relining brings a hundred year old flue up to a safe standard without tearing the chimney down.

The masonry on many older homes is still sound. It is the clay tile inside that has failed. A stainless liner solves the safety problem while leaving the brick and the look of the chimney alone.

It also matters when you switch a fireplace to gas, or add a stove or insert. The new appliance needs a correctly sized liner, and dropping one into an unlined or oversized flue is a common mistake we get called to fix.