DuraVent DuraFlex Stainless Steel

Why a brick chimney gets a stainless liner

A flexible chimney liner carries exhaust from fireplace inserts, freestanding stoves, furnaces, boilers and water heaters through a masonry chimney to the top. Have the existing chimney cleaned, inspected and repaired first. Compare our chimney liners, DuraFlex aluminum for gas only, or DuraLiner, a rigid, factory insulated option for wood.

Three liners and the kits built on them

The standard stainless suits wood, oil and non-condensing gas in chimneys with few bends and noncorrosive exhaust. The more corrosion resistant stainless handles coal or high sulfur oil and can be shaped oval through tight openings. DuraFlex Pro uses that corrosion resistant steel with deeper folds and 20 percent more steel per foot for several bends.

Basic kits include a coil, supporting top plate, removable rain cap and bottom connector. Tee kits replace the connector with a capped tee for side entry. Lengths run from 15 to 35 feet, with 50 feet available in 7 and 8 inch. For wood burning inserts in old factory built fireplaces, the reline kit needs no insulation and requires a metal chimney at least 8 inches inside and no more than 14 inches outside.

The pieces around the liner and the insulation

Top plates support the liner, while caps, tees, connectors and insert adapters finish the connections. Spacer rings hold a bare wood liner 1 inch off the masonry to maintain the clearance to masonry for wood burning. You add insulation and the spark arrestor on the page because the kits do not include them. Half inch ProFoil lets wood liners contact masonry and helps warm the flue for better draft and less condensation. ProMesh protects the wrap, and foil tape seals its seam. A freestanding stove also needs black stove pipe indoors.

Why buy DuraFlex stainless from My Cozy Outdoors?

We are an authorized DuraVent dealer, and the full manufacturer warranty applies. Browse the DuraVent range, but keep components within their own line rather than mixing parts. Send us the appliance model and a sketch of the run and we will write the parts list.

Your liner questions

How long does a stainless steel chimney liner last?

Life depends on steel matching fuel, appliance sizing for warmth and draft, wood liner insulation, and regular sweeping and inspection. Coal or high sulfur oil calls for the corrosion resistant liner. The full manufacturer warranty applies through us, and we can read you the terms for the version you pick.

Does the liner need to be insulated?

For a wood burning appliance the answer is usually yes, because bare liner needs a 1 inch masonry gap. Half inch foil-faced insulation permits contact. Gas, oil, pellet and the factory built reline kit need none against masonry. Ask your sweep or inspector to check the framing clearance.

Is a DuraFlex stainless liner right for a wood stove or insert?

Yes, match the appliance outlet, usually 6 inches, and insulate for wood. Use a tee for side entry or an adapter for a flat insert outlet. Freestanding stoves still need black stovepipe indoors. A brick chimney serving either appliance can use a DuraFlex stainless steel liner.