Level 1 sweep and inspection to the NFPA 211 annual standard - flue, crown, cap, and flashing checked and photographed
Chimney sweep logs do not sweep chimneys. They loosen some creosote - which then falls where a brush and vacuum still have to collect it.
DuraFlex Chimney Liner & Rebuild in Boston: What to Know First
DuraFlex chimney liner and rebuild work in Boston typically runs $2,400 to $6,800 depending on flue height, liner diameter, and how much of the masonry needs to come down and go back up. Most full liner replacements on a standard two-story Boston single-family take one day; a full rebuild from the roofline up runs two to three. We’re an independent DuraFlex service provider, not an authorized dealer, and we quote a written price before any work starts.
This page is for homeowners in Boston proper and the inner suburbs who already have a DuraFlex liner or are considering one, and need to know what failure looks like, what repair costs, and when a rebuild is actually the cheaper long-term move. Call (857) 567-8887 and Corrine or a member of her team will walk you through what you’re seeing.
How DuraFlex Products Fail - and How We Fix Them
- DuraFlex 316L alloy liners pitting at the seam welds. Boston’s coastal salt air plus acidic flue gases from gas appliances eats at the weld points before the tube walls. We see this most on gas-fired systems where condensation sits in the lower bends. Fix: we cut the deteriorated section and repipe, or swap the full liner if pitting runs more than 30% of the tube. 316L is the right alloy for gas; we don’t downgrade.
- DuraFlex AL29-4C liner with rippled inner walls after a chimney fire. AL29-4C is a high-temp stainless that handles oil and wood, but when creosote ignites, the liner’s inner surface can warp into waves you can see on camera. This is a genuine failure, not cosmetic: the ripples trap creosote and the liner’s cross-section narrows. Fix: full liner replacement, and we document the before and after with camera footage because the cause matters for your homeowner’s insurance.
- Flexible liner kinked at the smoke chamber transition. On older Boston triple-deckers along Dorchester Avenue and in Southie, the offset between the fireplace throat and the flue is tight. Installers who don’t take the time to radius the liner through the smoke chamber leave a kink that restricts draft and catches soot. We’ve pulled liners that were running at maybe 60% of their intended cross-section. Fix: remove, re-route with proper standoffs, and insulate the annular space. On a rebuild, we’ll correct the smoke chamber geometry so the liner isn’t fighting the house.
- Mortar crown failure pulling the liner with it. This isn’t unique to DuraFlex, but Boston’s freeze-thaw cycle punishes crowns. When the crown cracks and spalls, the top plate and liner clamp start moving, and water travels down the outside of the liner into the flue cavity. We see rust streaks on the liner exterior that tell the story. Fix: new poured crown with proper overhang and drip edge, new top plate, and a cold-weather sealant rated for New England winters.
- Undersized DuraFlex liner installed to satisfy a home inspection. Many homes sold between 2015 and 2025 got a liner installed because the inspector flagged the flue, and the selling agent called whoever was cheapest. The result is often a DuraFlex liner that’s one size too small for the appliance it serves. You get slow starts, smoke rollback, and CO readings that don’t sink. Fix: we measure the appliance’s BTU input and flue diameter against code, then repipe to the correct size. This is the one where we show the homeowner the numbers because the fix is straightforward but the mistake was preventable.
Our DuraFlex Chimney Liner & Rebuild Process

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Call and schedule. A live person answers 24/7 at (857) 567-8887. We book the visit, assign a named technician, and text you when they’re on the way.
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Camera inspection first. We run a Level 2 NFPA 211 camera scan down the flue before quoting anything. You see the footage with us. Corrine Halstead built this company on the principle that the camera doesn’t guess, and neither do we.
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Written scope and price. You get a written quote with line items for the liner, insulation, top plate, crown work, and any masonry rebuild. Clause 1 of the Haven Standard: a written price, written scope, and written warranty before anyone starts.
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Parts decision. We use OEM DuraFlex components where the warranty clock matters, and honest aftermarket parts where they don’t (flashing, minor connectors). We’ll tell you which is which and why, in dollars.
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Demo and install. The old liner comes out, the flue gets cleaned, the new liner goes in with proper insulation and standoffs. If it’s a rebuild, the mason work happens at the roofline or top section in the same visit window.
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Documented close-out. Camera re-scan, draft test, and photos of the finished work. You walk away with the photo record and the written warranty under the 365-Day Done Right Promise.
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AfterWhat DuraFlex Chimney Liner & Rebuild Costs in Boston
Straightforward liner replacement on a two-story Boston home, DuraFlex 316L or AL29-4C, runs $2,400 to $4,200 with standard accessories. A liner plus crown rebuild lands $3,800 to $5,500. Full rebuild from the roofline up with new flue, masonry, and liner: $5,000 to $6,800 on typical Boston row houses and triple-deckers. Height, access difficulty, and the condition of the existing masonry are the three things that move the price. We quote flat written prices, not hourly. Call (857) 567-8887 for a free estimate with a camera scan included.
Why Boston Homeowners Call Level Two Chimney Boston for DuraFlex Work

Because we show you the camera footage before we ask for a signature. That’s been our practice since 2009, when Corrine started running a camera down every flue and handing homeowners a written price the same visit. 38,000 chimneys inspected and cleaned since then, every one with a photo record and a written quote before any work started. Our techs are background-checked, uniformed, and know DuraFlex liner failure patterns in Boston’s older housing stock. If a DuraFlex liner isn’t the right repair, we carry and work with HeatShield and Gelco alternatives and we’ll tell you in plain terms which one makes sense and what each costs. The 365-Day Done Right Promise applies to every job, no fine print on liner work.
FAQs
It depends on the original installation date and whether the failed liner shows signs of improper installation. DuraFlex warranties typically cover material defects, not installation errors or damage from a chimney fire. As an independent DuraFlex service provider, we can’t process manufacturer claims, but we document everything on camera so if your liner failed due to a defect, you have the evidence to pursue it. Call (857) 567-8887 and we’ll assess whether the issue is a warranty matter or a wear-and-tear repair.
If the pitting, kinking, or warping runs less than 30% of the liner’s length, we can often section in a repair. More than that, or any failure at the weld seams or smoke chamber transition, and replacement is the cheaper long-term move. We’ll show you the camera footage and give you both numbers in writing before you choose.
Most one-day liner replacements are scheduled within a week of the written quote. Rebuilds take longer because of masonry curing time. We don’t promise same-day anything, but we do show up when we say we will, and you’ll get a text when the tech is on the way.
Possibly. We’ve looked at flues where another company quoted $8,000 for a rebuild, and the actual fix was a crowned liner and some parging. That’s why we encourage a free second opinion on any written estimate: bring us the quote, and we’ll show you what we see on camera. If you genuinely need the rebuild, we’ll tell you that too, with photos.
Yes, DuraFlex 316L is the right alloy for gas flue gases in Boston’s climate because it resists the acidic condensate gas appliances produce. The failure we see most in Boston is installer error, not material error: wrong sizing or a kink at the transition. Get the liner sized to the BTU input, which we’ll verify before quoting.
Written by Corrine Halstead, Owner, Level Two Chimney Boston at Level Two Chimney Boston, serving Boston and nearby areas.





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