Reline or Rebuild After a Fire?

Three Roads After a Damaging Fire

Once the inspection after a chimney fire is done, most owners face one of three choices. Reline the flue and keep the chimney. Rebuild part or all of the chimney. Or stop burning wood and switch to gas, in the same firebox or a new one. Each has its place, and the inspection report usually makes the right one clear. This post explains how.

What the Liner Does, and Why Fires Crack It

The liner is the inside wall of the flue. In most older chimneys in Sherman Oaks and the rest of the Valley it is clay tile, stacked in sections with mortar joints. Clay works well at normal temperatures but cracks when it heats fast and unevenly, which is exactly what a creosote fire does. The result is vertical cracks in one or more tiles, pieces broken out, and joints that opened.

A cracked liner is not safe, because it lets heat and gases reach the brick around it and, in older houses, the wood framing that sits close to the chimney. NFPA 211 treats the liner as essential, and a chimney with a failed liner should not be used until it is repaired or replaced.

When Relining Is the Right Answer

Relining fits when the damage stops at the liner. The camera shows cracked tiles or open joints, but the brick shell is sound, the chimney is straight, and the crown can be repaired.

The usual reline after a fire is a stainless steel liner run from the top of the chimney down to the smoke chamber, sized to the fireplace or to the insert you plan to use, and insulated where clearances call for it. Stainless handles heat far better than clay and holds up better in an earthquake. Relining is quoted in writing after the camera run, because the height, the flue size and the shape of the smoke chamber all change the price.

Signs relining will do: the cracks are inside only, there is no smoke coming through the outside brick during a fire, and the stack shows no lean or cracks at the roofline.

When a Rebuild Is the Right Answer

A rebuild fits when the damage went past the liner. The brick shell cracked from the inside, smoke leaked through the mortar during the fire, the crown and top courses broke apart, or the chimney was already weak from an old quake and the fire finished the job.

A partial rebuild takes the chimney down to sound masonry, often at or near the roofline, and builds it back with reinforcement and a new liner, crown and cap. A full rebuild goes to the firebox. Work below the roof is usually permitted by the city. A rebuild is always quoted in writing after inspection.

Signs a rebuild is likely: cracks visible on the outside of the chimney after the fire, bricks loose at the top, a lean, or a camera run that shows the brick behind the tile cracked.

When Switching to Gas Makes Sense

Some owners do not want to burn wood again after a fire. Two options keep a working fireplace without the creosote that fed the fire.

• - A gas insert goes into the existing firebox with its own liner. It runs $2,800 to $5,650 installed in an existing fireplace and puts real heat into the room. The flue still needs to be sound enough to hold the liner, but it no longer carries the fire.
• Gas logs sit in the existing firebox for the look of a fire. Vented logs need a sound flue and an open damper.

A third option avoids the old chimney entirely: a direct-vent gas fireplace in the same wall or a new spot, venting straight out through the wall or roof. It runs $4,500 to $9,050 and suits a chimney that would need a rebuild before any fire could go into it again.

What Decides Which Road Is Yours

Four things decide it: how far the damage reached, the age and build of the chimney, what you want to burn next, and the budget. A sound chimney with a cracked liner is a reline. A chimney cracked through is a rebuild or a switch to direct-vent gas. A sound chimney and an owner done with wood is an insert.

The camera run settles the first two. You settle the last two. Send us photos of the chimney and the firebox through our quote form, say what you would like to burn next, and we will tell you which inspection to book and which roads are open, before the visit.

How Long Each Road Takes

Timing matters when winter is coming. A reline is usually done in a day or two once the liner is in hand, and the fireplace can be used as soon as it is finished and photographed. A gas insert is about the same, plus the time for a gas permit and inspection where the city requires one. A partial rebuild above the roof takes several days on site, waits for dry weather so the mortar cures, and may need a permit. A full rebuild or a new direct-vent fireplace takes longest, from permit to final sign-off. We give you the expected timeline in writing with the quote, so you can plan around it.

Questions Worth Asking Any Contractor

• - Did you see the full flue on camera before quoting?
• Is the liner sized for what I plan to burn?
• Does the quote separate fire damage from upgrades?
• Who handles the permit, if one is needed?
• What do I get at the end: photos, a sign-off, a note on the first fire?

The Next Step

If your chimney had a fire and you are weighing a liner against a rebuild, start with the inspection, then choose. Owners in Sherman Oaks can call us to book a Level 2 and get the options laid out in writing.