By Johnathan Mason, Ace Chimney Service.
When a flue needs relining there is more than one way to do it, and the right answer depends on the chimney, the appliance, and the condition of the masonry around it. Here is an honest comparison rather than a sales pitch for whichever one we happen to be holding. Useful background for any Cary homeowner who has just been told their liner has failed.
What the liner is doing
Three jobs. It contains combustion products so they go outside rather than into the structure. It protects the surrounding masonry from heat and from acidic condensate. And it is sized to the appliance so the system drafts properly. A chimney with a failed liner fails at all three at once.
Clay tile
The traditional lining in masonry chimneys and still perfectly good when intact. Inexpensive as a material, long-lasting, and resistant to normal flue temperatures. Its weaknesses are the mortar joints between sections, which open over time, and its poor tolerance of the rapid temperature spike of a chimney fire — tiles crack. Replacing tile in an existing chimney means breaking into the structure, which is why it is common in new construction and rare as a repair.
Stainless steel
The workhorse of relining. A continuous rigid or flexible stainless liner is run down the existing flue and sealed top and bottom, insulated where needed. Advantages: no joints to fail, correct sizing for the appliance, suitable for wood, gas, or oil with the right alloy, and installable without dismantling the chimney. It is the usual answer for fitting a wood stove or insert. Different alloys suit different fuels, and using the wrong grade on the wrong appliance shortens its life considerably.
Cast-in-place
A cementitious material is pumped into the chimney around a form, creating a smooth, seamless liner bonded to the existing structure. Its distinctive advantage is that it can add structural strength to a deteriorating chimney rather than simply passing through it, which makes it a candidate for older stacks that are losing integrity. It is a more involved installation and a permanent one — there is no removing it afterwards.
How the choice actually gets made
By what the chimney is like inside and what appliance is going on it. A sound masonry chimney taking a wood insert is a straightforward insulated stainless job. A deteriorating older stack may be better served by cast-in-place. A chimney with a single cracked tile and otherwise sound construction may not need a full reline at all. That determination comes from a camera scan, which is why inspection precedes any recommendation. Our chimney relining page covers the work itself.
Ace Chimney Service has 29 years in the trade, is insured and bonded, and gives the price up front before anything starts. Seven days a week, 7 AM to 7 PM, Crystal Lake and McHenry County. Call (815) 320-0883 or see pricing.
Frequently asked questions
How long does a stainless liner last?
A properly specified and installed liner in the right alloy for the fuel lasts many years. Wrong alloy or an unswept flue shortens it substantially.
Does a liner need insulation?
Often, especially on exterior chimneys and with wood appliances. Insulation maintains flue temperature, which improves draft and slows creosote.
Can one cracked tile be repaired instead of relining?
Sometimes, depending on location and severity. It should be a judgement based on a camera scan, not an automatic upsell.
Is cast-in-place better than stainless?
Neither is universally better. Cast-in-place suits deteriorating structures; stainless suits sound chimneys and appliance changes.
Can a liner be installed in a chimney with bends?
Flexible stainless handles moderate offsets. Severe bends complicate any method and need assessment first.
Do relined chimneys still need sweeping?
Yes, annually. A liner changes the surface, not the need for maintenance.
Will relining fix my draft problem?
If the cause is an oversized or leaking flue, usually yes. If the cause is chimney height or a rough smoke chamber, it will not.
Is relining required for a gas conversion?
Frequently, because gas exhaust is cooler and wetter and an oversized masonry flue lets it condense and attack the masonry.
Published September 24, 2026