The flue — the passage inside the chimney — is the part nobody sees and the part that fails inspections. Most of the liner work Chimney Moncton refers starts the same way: someone finally looked down the chimney with a light or a camera, and what they found ends up in a WETT report or a home-inspection summary. The repair, in most cases, is a stainless steel liner at $2,000–$4,500.
How clay flue tiles die
Most masonry chimneys built here since mid-century were lined with clay flue tiles — fired terracotta sections stacked and mortared inside the stack. Clay is fine until it isn't: every fire heats the tiles unevenly and thermal shock opens hairline cracks; the mortar between tile sections erodes; moisture from a failed crown or from flue-gas condensation soaks in, and New Brunswick's freeze-thaw cycles do to the tiles exactly what they do to the brick outside. Oil-fired appliances add their own attack — acidic condensate from cooler modern oil-furnace exhaust chemically eats tile and mortar from the inside.
The result is what a camera scan shows on chimney after chimney in this region: cracked tiles, offset joints, missing mortar, tile faces spalling into the flue. Each gap is a path for heat and combustion gases into the chimney's core — and eventually toward the house framing. This is not a cosmetic finding, which is why inspectors won't shrug at it.
The fix: a 316 stainless steel liner
Relining threads a continuous 316-alloy stainless steel liner — the grade specified for wood and oil service because it withstands both heat and corrosive condensate — down the existing flue, sized to the appliance it serves. For wood-burning connections the liner is insulated, wrapped in a high-temperature blanket or set in poured insulation, then connected top and bottom: a plate and stainless cap up top, a proper connection to the stove, insert or furnace below. Where broken tile blocks the passage, the old tile is broken out first.
Insulation is not an upsell — it's physics. An insulated liner keeps flue gases hot the whole way up, which maintains draft (the chimney actually pulls) and keeps the gas above its condensation point so far less creosote — the combustible tar of wood smoke — condenses on the walls. A cold exterior chimney with an uninsulated liner is a creosote factory in a New Brunswick winter.
The orphaned flue — Moncton's quiet epidemic
Southeastern New Brunswick is converting off oil heat at a remarkable clip, and every heat-pump conversion leaves something behind: a chimney flue with no appliance, or worse, an orphaned water heater — a small gas or oil water heater left venting alone into a flue sized for the furnace that's gone. The big cold flue barely warms up, exhaust condenses on the way out, and the moisture attacks tile, brick and mortar year-round. Meanwhile a fully unused flue stops getting the drying warmth that kept it healthy for decades, and deteriorates faster than when it worked for a living.
The fixes are cheap relative to what they prevent: a correctly sized liner for the remaining appliance, or — if the flue truly serves nothing — capping and venting the stack properly so it stops eating itself. If your oil tank left in the last five years, your chimney belongs on someone's inspection list.
Oversized flues and wood stoves
The classic Maritime setup: a wood stove or insert vented into a big old fireplace or furnace flue. An oversized flue means slow, cool exhaust — weak draft, smoke roll-back on lighting, and heavy creosote condensation, which is a chimney-fire risk in a province that burns as much wood as this one. A liner sized to the stove's collar transforms the system: sharper draft, cleaner burn, dramatically less creosote, and a flue that can actually be swept properly. This exact configuration — unlined or oversized flue serving a wood appliance — is among the most common deficiencies written up in WETT inspections, and relining is the standard corrective the re-inspection wants to see.
When the masonry can't carry a liner — and the Class-A alternative
A liner restores the flue; it can't restore the structure around it. If the stack is spalled, cracked or leaning, the honest scope is masonry first — a roofline-up or full rebuild — with the liner installed in the same mobilization while the top is open. One staging setup, one clean result, and the finished system passes inspection inside and out.
And sometimes the right answer skips masonry entirely: where a chimney is beyond economic saving — or where a homeowner wants a wood stove on a wall with no chimney at all — a Class-A insulated chimney (factory-built, stainless, double- or triple-wall) runs up the exterior or through the roof. It's routinely the cheaper path to a WETT-passing wood installation than resurrecting a dead stack, and partner professionals quote both options when both are on the table. Every relevant range sits on the cost page.
Winter-friendly work: unlike masonry, liner installation doesn't need curing weather — most relines can proceed in cold months. If a WETT report or home inspection flagged your flue in November, you don't have to wait for spring to close the file.