Gas fireplace service
Sweep & inspection
Caps & crowns
Flue relining
Masonry repairLevel 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.
Why San Francisco Homeowners Choose DuraFlex Chimney Cleaning
We clean, inspect, and repair DuraFlex in San Francisco, and we do it as an independent service provider, not a factory-authorized dealer. What that means for you is simple: we have zero incentive to sell you a new DuraFlex product when your existing one can be cleaned and made safe. Ruben Castellano and our crew have pulled enough DuraFlex SS and AL liners out of century-old Bay Area flues to know exactly how this brand behaves in real San Francisco conditions, from Pacific Heights Victorians to fog-belt Sunset bungalows.
Our DuraFlex work is backed by the same written guarantee we put on every repair: if it fails within the coverage period, the second visit is free. Call (831) 534-3789 for a written estimate before any work begins.
Why Trust Alcott Chimney San Francisco for Your DuraFlex Chimney Cleaning?
Most chimney companies in San Francisco can sweep a flue. Far fewer can tell you that the DuraFlex liner they are looking at is a 316L stainless SS model rated for wood, not a thinner aluminum AL model that should never see wood-burning temperatures. Our technicians work with DuraFlex products every week. They know the corrugation pitch. They know which ProConnect couplings tend to loosen on long vertical runs in older homes. They know when a liner can be patched and when a full reline is actually the cheaper honest answer.
Ruben Castellano grew up in East Los Angeles and learned the fundamentals at Los Angeles Trade-Technical College before spending nearly two decades cleaning and inspecting chimneys across California. He and his crew have served San Francisco homeowners for years, and Ruben has built a name for calling problems exactly as he finds them. No upsell, no scare tactics. Tell me what you’re seeing, and I’ll tell you straight what it means.
Every technician who arrives at your door is background-checked and identity-verified under the Threshold Standard. You will know the technician’s name and see their photo before we arrive, and they will show a photo ID badge at the door. Every time, no exceptions.
Styles & brands we work with
Common DuraFlex Chimney Cleaning Problems We Fix in San Francisco
DuraFlex makes solid liner products. The failures we see are almost always installation-related or the result of using the wrong liner type for the appliance. Here are the issues we encounter most often in San Francisco homes:
- Corrugation valleys trapping creosote and soot. DuraFlex SS and AL liners have a ribbed interior. Over time, the valleys between corrugations collect creosote, the tar-like buildup that causes chimney fires. This is worse on long runs where the flex was stretched too far during installation, which flattens the corrugation and makes brushing less effective. We see this constantly in three-story San Francisco Victorians with 30+ foot flue runs. A standard poly brush will not remove hardened Stage 3 creosote from those valleys. We use rotary cleaning heads and sometimes chemical treatments to break it down.
- Torn or kinked flex liner at the first offset. When a liner is pulled through an old brick flue with a sharp bend near the smoke chamber, the flex can kink or tear. Last winter, our crew pulled a DuraFlex SS liner from a Pacific Heights fireplace and found a 3-inch tear right at the first offset. The previous installer had forced the flex too sharply. We cut out the damaged section, spliced in a new OEM DuraFlex coupler, and ran a Level 2 camera scan to confirm the rest of the liner was sound. The homeowner had been smelling smoke on windy days; after the repair, the draft held steady and the smell was gone.
- Pinhole corrosion in DuraFlex AL used with wood-burning appliances. DuraFlex AL is an aluminum liner rated for gas appliances. When someone installs it on a wood-burning fireplace or insert, the aluminum cannot handle the flue gas temperatures. The result is pinhole corrosion, which lets carbon monoxide and other combustion gases seep into the chimney chase or wall cavities. We find this in older San Francisco homes where a previous owner or handyman cut corners. The fix is a full reline with a stainless DuraFlex SS liner, not a patch.
- Loose or leaking ProConnect couplings. DuraFlex ProConnect fittings use a push-together design that speeds installation. On long vertical runs, especially in homes where thermal expansion and contraction is constant, those couplings can work loose. A loose coupling lets flue gas escape into the chase. During a Level 2 inspection, we check every coupling joint with a camera. When we find a leaking coupling, we reseat it and often add a mechanical fastener as a secondary lock.
- Moisture intrusion through an improperly sealed top plate. San Francisco fog is relentless. When a DuraFlex top plate is not sealed correctly, or the wrong top plate was used for the liner diameter, moisture drips down the outside of the liner and sits against old brick. Over a decade, that moisture accelerates mortar decay behind the liner. We reseal top plates and replace undersized plates regularly on fog-belt homes in the Richmond and Sunset districts.
DuraFlex Parts & Our Repair-vs-Replace Approach
We use OEM DuraFlex fittings whenever possible. Couplers, top plates, and caps have a specific corrugation pitch, and aftermarket parts that do not match that pitch will not seat correctly. For liner wall repairs, we will install a quality aftermarket stainless patch if the original liner section is mostly sound. But we are straight with you when patching is a short-term fix. If a liner has multiple pinhole corrosion sites, or the flex has been stretched and flattened in several places, a full reline is often cheaper than repeated service calls. Ruben’s rule is simple: we recommend the repair we would choose on our own home.
We keep common DuraFlex couplers, top plates, and caps stocked for fast turnaround on San Francisco jobs. If your specific part is not in the truck, we can usually source it within a day or two. Call (831) 534-3789 and we will give you a straight answer on cost before anything is ordered.
Our DuraFlex Service Process – Step by Step
- 1
Diagnosis. We start with a Level 2 camera inspection of the entire flue run. For DuraFlex liners, we are looking at corrugation condition, coupling integrity, top plate seal, and any evidence of condensation or flue gas leakage. You see the footage. We do not ask you to take our word on a repair you cannot see.
- 2
Written estimate. After the inspection, you get a written price for any recommended work. No work starts until you approve that number in writing.
- 3
Repair or install. If your liner needs a splice, a coupling reseat, or a full reline, we use OEM DuraFlex fittings wherever the liner wall is being joined. For a full reline, we size the DuraFlex SS or AL liner to the appliance, not the other way around.
- 4
Test. After any repair or installation, we run a draft test and a second camera pass. If we replaced a section, we verify the coupling seated correctly and there is no obstruction.
- 5
Written guarantee. Every repair carries a written guarantee. If that repair fails within the coverage period, the second visit is free. That is the 365-Day Done Right Promise.
See the difference
Before
After
Before
After
Before
AfterDuraFlex Products We Service & Install in San Francisco
Our crew works on every DuraFlex product line in current use across San Francisco: DuraFlex SS stainless steel flexible liner for wood and pellet appliances, DuraFlex AL aluminum flexible liner for gas, DuraFlex ProConnect push-fit systems, and DuraFlex Smooth Wall hybrid rigid/flex liner for those long runs where maximum draft matters. We also keep a limited stock of OEM DuraFlex couplers, top plates, and caps in our service vehicles for same-visit repairs whenever possible.
We Also Service These Brands
DuraFlex is one of the brands we work with most often, but it is not the only one. We also install and service HeatShield cerfractory resurfacing systems and Gelco liner products. If you have a mixed-brand chimney system, we can service all of it in a single visit.
FAQs – DuraFlex Chimney Cleaning Service in San Francisco
No, we are an independent DuraFlex service provider, not a factory-authorized dealer. That independence matters. We are not incentivized to sell you a new DuraFlex product when your current liner can be cleaned and repaired. We service DuraFlex liners based on what we actually find inside your flue.
For couplings, top plates, and caps, we use OEM DuraFlex whenever possible because the corrugation pitch must match for a proper seal. For liner wall repairs, we will use a quality aftermarket stainless patch only if the original is mostly sound. If the liner wall is beyond salvage, we will say so and recommend a full reline. Call (831) 534-3789 and we will walk you through exactly what your flue needs.
A standard poly brush will handle light Stage 1 creosote in a DuraFlex liner. But the ribbed interior traps heavier buildup in the corrugation valleys. For Stage 2 or Stage 3 creosote, we use rotary cleaning heads or chemical treatments to get the valleys clean. Brushing too aggressively with a metal brush can damage the liner wall, so we match the brush to the liner condition.
In most San Francisco homes, the first bend is at the smoke chamber where the flue transitions from vertical to angled. When a flex liner is pulled through too sharply at that transition, the corrugated wall kinks and can tear. We have pulled liners with exact 3-inch tears at that spot. The fix is cutting out the damaged section and splicing in a new section with OEM couplers. We have done this repair dozens of times.
No. DuraFlex AL is an aluminum liner rated for gas appliances. Wood-burning inserts produce flue gas temperatures that aluminum cannot handle, and the result is pinhole corrosion that can leak carbon monoxide into your home. If you have DuraFlex AL on a wood-burning insert, we will tell you straight: that liner needs to come out and be replaced with DuraFlex SS. Call (831) 534-3789 for an inspection and a written recommendation.
The camera tells us. If the corrugation is intact, the couplings are seated, and there is no pinhole corrosion or stretch-flattening, then a thorough cleaning usually gets the liner back to safe operation. If we find multiple corrosion sites, stretched sections, or tears, replacement is often less expensive than repeated patching over the next few years. We show you the footage either way.
Book Your DuraFlex Service in San Francisco, CA
If your DuraFlex liner needs a Chimney Sweep, an inspection, or an honest repair assessment, call Alcott Chimney San Francisco at (831) 534-3789. You will get a written estimate before any work starts, a written guarantee on every repair, and a technician whose name and photo you will know before they knock on your door.
Written by Ruben Castellano, Owner at Alcott Chimney San Francisco, serving San Francisco homeowners since 2002.