For most Connecticut homes the answer is a stainless steel liner: it is manufactured to a known diameter, it can be sized precisely to the appliance, it goes in without dismantling anything, and qualifying products carry the manufacturer's own lifetime warranty. A cast-in-place liner comes into its own for a different problem — a chimney whose masonry has deteriorated to the point that it needs strengthening as well as sealing.
Put simply: stainless fixes the flue. Cast-in-place fixes the flue and the chimney around it.
Stainless steel liners
A continuous stainless liner is dropped the full height of the flue and connected to the appliance at the bottom and terminated at the top. Because it is a manufactured product it comes in defined diameters, which is what makes precise sizing possible.
It suits: a wood stove or insert going into an oversized fireplace flue; a gas or oil appliance that needs a smaller, corrosion-resistant flue; a clay-lined chimney whose tiles have cracked; a chimney where the masonry itself is sound.
Worth knowing: insulation matters as much as diameter. On an exterior or otherwise cold chimney, an uninsulated liner will not reach temperature. ABC Chimney Solutions insulates where the run calls for it rather than as an upsell.
On the warranty: qualifying stainless liner products carry the manufacturer's lifetime product warranty. That is a warranty on the product from the company that made it — it is worth being precise about that, because it is not the same thing as an unlimited guarantee on the installation.
Cast-in-place liners
A cast-in-place liner is a cementitious material poured around a temporary form inside the existing flue and left to cure. When the form comes out, what remains is a smooth, seamless, insulating flue bonded to the chimney.
It suits: older masonry chimneys with deteriorated or missing clay tile; chimneys where the mortar joints between tiles have failed badly; stacks that need structural reinforcement as well as a flue; irregular or unusually shaped flues that no manufactured pipe fits well.
Worth knowing: it is a bigger operation than dropping a liner in, it needs curing time and appropriate temperatures, and the finished diameter is set by what the existing flue allows rather than chosen freely.
How the choice is normally made
ABC Chimney Solutions asks three questions.
What is the appliance?
If a specific diameter is required for a specific stove or boiler, stainless makes hitting that number straightforward.
What condition is the masonry in?
This is usually the deciding one. A sound chimney with a failed flue is a stainless job. A chimney whose structure is being held together by habit is where cast-in-place earns its cost, because it adds strength rather than just passing through.
What is the alternative?
Sometimes the honest comparison is not stainless versus cast-in-place at all, but relining versus rebuilding. Where a long list of repairs starts approaching the cost of rebuilding the damaged section, we will say so rather than quote the list.
The third option
Where the original build allows it and only some tiles have failed, clay tile relining replaces them section by section. It is more limited in scope but it keeps an original chimney original, which matters on some properties.
All three sit on the chimney liners hub, and there are photographs of liner installations we have done on the projects page.
Frequently asked
Which liner lasts longer?
Both are long-term solutions when correctly installed. Qualifying stainless liner products carry the manufacturer lifetime product warranty; a cast-in-place liner is a permanent cementitious flue. ABC Chimney Solutions chooses on the condition of the chimney rather than on longevity alone. Learn more about this service.
Is cast-in-place more expensive?
It is normally a larger job, but ABC Chimney Solutions finds it can be the cheaper route overall when the alternative is relining and separately repairing deteriorated masonry, because a cast-in-place liner does both at once. Learn more about this service.
Can a liner be fitted in an unlined chimney?
Yes. An unlined masonry chimney is one of the clearest cases for relining, and ABC Chimney Solutions will advise which method suits the flue shape and the condition of the surrounding masonry. Learn more about this service.