DuraFlex Chimney Liner & Rebuild in San Francisco: What to Know First
We provide independent DuraFlex chimney liner and rebuild service throughout San Francisco, with most jobs completed in a single visit and upfront pricing that matches the final invoice. A typical DuraFlex liner replacement runs $2,800-$4,500 depending on flue height and access, while partial rebuilds start around $1,800. We do not mark up parts or hide labor hours, and every job ends with a live video review of the work.
This page is for homeowners in San Francisco who already have a DuraFlex liner installed, suspect it is failing, and want a technician who knows the difference between a DuraFlex SS and a DuraFlex Pro without reading the label twice. If that describes your situation, call (855) 408-5567. A live person answers, 24 hours a day.
How DuraFlex Products Fail - and How We Fix Them
- DuraFlex SS (stainless steel) liners: We see these most often in Pacific Heights and Nob Hill Victorians where the original clay flue was relined in the 1990s or early 2000s. The SS series develops pinpoint corrosion at the flex points where the liner bends to accommodate offset flues in these older chimneys. San Francisco’s salt-laden fog accelerates this at the top third of the stack, above the roofline where ventilation is constant. We cut out the damaged section, splice in a new SS segment with a factory-approved coupling, and seal the joint with high-temp silicone rated to 1,200°F.
- DuraFlex Pro flexible liners: The Pro series uses a heavier gauge steel and shows different symptoms. In the Richmond District, where chimneys tend to be shorter and wider, we find Pro liners that have settled or “bellied” at the first offset, creating a low spot where creosote pools. The liner itself is intact, but the sag blocks proper draft and can lead to smoke backup into the living space. We pull the liner, re-establish proper slope with a custom-formed transition piece, and reinstall with improved support spacing.
- DuraFlex SW (smooth wall) liners: These are marketed for improved draft and easier cleaning, but the smooth-wall construction is less forgiving of installation errors. In Noe Valley and the Castro, where terra cotta flues often have hidden fractures, an SW liner installed without proper centralization can chafe against sharp tile edges. We find circumferential scoring 8-12 inches above the smoke chamber. Our fix: remove the liner, repair the flue wall with HeatShield Cerfractory Foam where appropriate, then reinstall with new centering brackets spaced every 4 feet.
- DuraFlex termination caps and storm collars: Not strictly the liner, but a common source of water intrusion that destroys liners from the outside in. The standard DuraFlex cap uses a slip-fit collar that loosens over time with thermal cycling. In the Sunset, where Warren Eckhart grew up two blocks from the fog line, we see this constantly. Water runs down the exterior of the liner, pools at the thimble, and rusts the bottom section from the outside while the inside looks fine. We replace with a Gelco locking-band cap or a custom-fabricated termination where the flue configuration demands it.
- DuraFlex ovalizer and adapter failures: When a round liner must pass through a rectangular flue, DuraFlex supplies ovalizing kits. In San Francisco’s pre-1906 earthquake housing stock, we find original installations where the ovalizer was forced rather than formed, creating stress fractures at the long axis. These do not always show on a basic Level-1 inspection. Our Level-2 camera inspection catches them, and we replace with a properly sized oval liner section or, in some cases, recommend a partial rebuild of the flue to accept a round liner without deformation.
Our DuraFlex Chimney Liner & Rebuild Process
- 1
Call and schedule. A live person answers, day or night. We ask about symptoms, the age of the liner if known, and the appliance type. We schedule a Level-2 inspection, usually within 48 hours.
- 2
Level-2 camera inspection. Warren’s technicians document every foot of the flue with a 360-degree camera. You see the footage. We deliver a plain-English verdict: repair, replace, or rebuild, with photos marked to show exactly where and why.
- 3
Parts decision. For DuraFlex liners, we source OEM DuraFlex components where the series is still supported. For discontinued lines, we use quality aftermarket equivalents from Olympia Chimney or Copperfield that match or exceed the original specification. We explain the choice and the warranty implications before ordering.
- 4
The repair. Our background-checked, uniformed technicians arrive with parts in hand. Most DuraFlex liner replacements and partial rebuilds finish in one day. We protect floors and furniture, work with dust containment, and keep the work area contained.
- 5
Post-repair testing. We run a smoke test or draft test depending on the appliance. The flue must perform to our standard, not merely to minimum code. If the flue isn’t right, the fire isn’t right. Everything else follows from that.
- 6
Documentation and guarantee. You receive photos of the completed work, a written report, and our 90-Day Done Right Promise. If it’s not right, we make it right. In writing, no arguing.
What DuraFlex Chimney Liner & Rebuild Costs in San Francisco
These are real numbers for San Francisco homes, based on jobs we have completed in the past 24 months. Every house is different, but this is the range you can plan around.
| Service | Typical Range | What Moves the Price |
|---|---|---|
| DuraFlex SS liner replacement (single flue, standard height) | $2,800 - $3,800 | Flue height, number of offsets, roof access difficulty |
| DuraFlex Pro liner replacement (heavy gauge) | $3,200 - $4,500 | Gauge upgrade, longer runs, custom transitions |
| Partial chimney rebuild with DuraFlex liner | $4,500 - $7,500 | Courses rebuilt, scaffolding needs, matching historic brick |
| DuraFlex liner repair (sectional splice, cap, collar) | $1,800 - $2,800 | Location of damage, parts availability, access |
| Level-2 camera inspection with written report | $289 - $389 | Number of flues, appliance types, documentation needs |
Factors that increase cost: three-story Victorian with steep roof pitch, chimney on the street-facing facade requiring sidewalk protection, historic district mortar matching, or discovery of concealed fire damage after liner removal. Factors that decrease cost: straight flue, good roof access, recent prior inspection with documentation.
We do not charge for the estimate, and the number on the estimate is the number on the invoice. Call (855) 408-5567 for an exact quote on your DuraFlex chimney liner or rebuild.
Why San Francisco Homeowners Call Hearthstone Chimney Co. of San Francisco for DuraFlex Work
We are not affiliated with or authorized by DuraFlex. We are an independent DuraFlex service provider, which means our only loyalty is to the chimney and the homeowner, not to a parts catalog or a corporate account manager.
The 90-Day Done Right Promise governs every job. If the draft is off, if a joint weeps smoke, if a cap loosens in the first winter wind, we return. No paperwork to file, no argument about whether it was “part of the original scope.” We fix it.
Our technicians carry DuraFlex, HeatShield, and Gelco components on most service vehicles. If your DuraFlex liner is discontinued or the lead time is unreasonable, we have alternatives that meet the same specification. You are not held hostage by a single brand’s inventory.
We have answered the phone with a live person for over 42 years. That matters when your chimney backs up smoke on a Saturday evening in December.
FAQs
No, independent service does not automatically void a DuraFlex warranty, but warranty claims require documentation of OEM parts and proper installation. We use OEM DuraFlex components where available and document every step so any remaining warranty coverage stays intact. If your liner is past the warranty period, which most in San Francisco are, we use quality aftermarket parts with their own material guarantees. Call (855) 408-5567 and we will check your series and manufacture date.
Most DuraFlex liner replacements in San Francisco are completed in a single day, with the technician arriving between 8 and 9 AM and finishing by late afternoon. Jobs that require scaffolding, historic mortar matching, or concealed damage repair may extend to a second day. We tell you before we start if that is likely. Call (855) 408-5567 to schedule.
We stock common DuraFlex SS and Pro components, and we maintain supplier relationships that give us access to the full catalog with typical lead times of 3-5 business days for uncommon sizes. For discontinued DuraFlex lines, we use compatible aftermarket parts from Olympia Chimney or Copperfield that match the specification. We never leave a chimney open waiting on a part. Call (855) 408-5567 to confirm availability for your specific model.
Repair is cheaper when the damage is localized to a cap, collar, or short section, typically $1,800-$2,800. Replacement becomes the better value when corrosion is widespread, the liner has settled or bellied, or the original installation used undersized or discontinued components. During our Level-2 inspection, we show you exactly what we see and recommend the path that costs less over the life of the system, not just today. Estimates are free. Call (855) 408-5567.
Yes. We service and install HeatShield, Gelco, Olympia Chimney, Famco, and Copperfield liners and components. Many San Francisco homes have mixed systems or prior repairs using multiple brands. Our technicians are trained to evaluate what is in place and recommend the best material for the repair, not merely the brand that matches. Call (855) 408-5567 for any chimney liner concern.
Written by Warren Eckhart, Owner & Master Sweep, Hearthstone Chimney Co. of San Francisco at Hearthstone Chimney Co. of San Francisco, serving San Francisco and nearby areas.