Flue relining
Sweep & inspection
Caps & crowns
Masonry repair
Gas fireplace serviceLevel 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 Flue Liner Replacement: The Dallas Owner’s Guide
DuraFlex flue liner replacement in Dallas typically runs between $2,400 and $4,800 installed, depending on liner length, diameter, and how much of the old system has to come out. We stock DuraFlex-compatible replacement components on our trucks, and most swaps take half a day once we’re on site. Homeowners usually discover the problem during a routine sweep or inspection, when our camera shows a cracked seam, a separated joint, or corrosion that’s been quietly eating through the liner for years.
The most common path to this page: you had a DuraFlex liner installed years ago, something looks off, and now you want to know if you’re looking at a $200 patch or a $4,000 rebuild. Nathan Corliss, our owner, puts it simply: “Tell you the price first, do the work right, put it in writing – that’s the whole job.” We’ll walk you through what actually fails on these liners, what it costs to fix in Dallas, and how to tell whether you need a full replacement or a targeted section swap.
Which DuraFlex Models This Applies To
DuraFlex makes stainless steel chimney liners in two primary series: the standard DuraFlex 316L alloy for wood-burning fireplaces and stoves, and the DuraFlex Pro (also 316L but with a heavier wall) for high-efficiency gas appliances and harsher exhaust conditions. Both use a corrugated, flexible tube design that connects to rigid connector sections at the appliance and termination points. If your liner says DuraFlex on the label plate at the top of the chimney or on the appliance connector, you’re in the right place.
One compatibility gotcha we see regularly in Dallas homes: the DuraFlex system uses a proprietary coupling band at each joint. You can’t mix DuraFlex tube with off-brand couplers and expect the connection to hold under thermal cycling. We’ve corrected more than a few DIY jobs where someone used a generic stainless band from a hardware store, only to have the joint separate within a year. When we replace a section, we use DuraFlex-spec components end to end. Aftermarket equivalents exist, but for flue liners, we don’t gamble with gas exhaust. The risk costs more than the savings.
To identify your liner size, measure the inside diameter of the existing tube at its widest point. Most Dallas homes with DuraFlex run 6-inch or 7-inch liners for fireplaces, with 4-inch common on gas inserts and larger 8-inch on older masonry fireplaces. The label plate near the top termination should list the model and diameter. If you can’t read it, we’ll identify it during the initial inspection.
Ashby Chimney Dallas is an independent service provider, not affiliated with DuraFlex. We install and repair their products because they hold up well in North Texas conditions, which is more than we can say for some liners we’ve pulled out.
Styles & brands we work with





Signs Your DuraFlex Flue Liner Replacement Is Failing
- You see rust flakes or staining at the cleanout door. This means moisture is getting inside the liner, usually at a failed joint or corroded seam. Water plus combustion gases equals acid, and acid eats 316L steel faster than most people think. We find this constantly in Lakewood and East Dallas homes where chimneys go years between inspections.
- Soot or staining around the fireplace opening that wasn’t there before. When a joint separates, exhaust pressure drops and gas finds the path of least resistance, which is sometimes back into the room. This is the one symptom you should treat as urgent. Carbon monoxide follows the same path.
- A whistling or fluttering sound when the fireplace is burning. Air is being pulled through a gap in the liner system. It’s not a tuning problem, it’s a hole.
- Visible cracks or separation at the liner joints during a top-down look. If you can see daylight through a seam from the top of the chimney, that liner is done. We document this with photos on every inspection so you can see exactly what we’re seeing.
- Water in the firebox after heavy rain without an obvious cap problem. The liner has failed somewhere up the flue, and rain is tracking down through the gap. In Dallas, spring storm season makes this the most common first symptom our customers notice.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For a full DuraFlex liner replacement in Dallas, budget $2,400 to $4,800 installed. The range comes down to three things: liner diameter, total flue height, and what has to be removed first. A two-story Lakewood Tudor with a 35-foot chimney costs more than a single-story ranch in Richardson with 18 feet of flue. If the old liner is wedged in with hardened mortar or the chimney needs a new crown and cap at the same time, you’re at the higher end.
Every quote we write includes the liner sections, couplers, termination cap, top plate, labor, and debris removal. You get one written price before we start, and that’s the number on the invoice when we finish. The Kingswell Guarantee covers every DuraFlex liner replacement we install. If the repair fails within the guarantee period, we come back and correct it at no charge. No fine print, no prorated nonsense, no arguing about whose fault it is. That’s the 365-Day Done Right Promise, and it’s in writing on every job.
In Dallas, expect the liner itself to run $900 to $1,600 for the tube depending on length and diameter, with the rest going to installation labor, connection hardware, and any cap or crown work. We show you the parts breakdown on the quote so you know exactly what you’re paying for. HeatShield and Gelco are two other brands we work with regularly, and we’ll tell you honestly if one of those is a better fit for your situation. Sometimes it is. Sometimes DuraFlex is the right call. We’ll explain why either way.
DIY or Call Us?
Here’s the honest split. Things you can safely check yourself: shine a flashlight up from the cleanout door to look for obvious rust or separation, check for water in the firebox after rain, and look at the top of the chimney for visible damage to the cap. None of that costs you anything and it helps you decide whether to call us.
What you should not do is pull a liner out of a chimney yourself. Flue liner work involves heights, heavy rigid sections, and gas connections. A liner that’s connected at the bottom to a gas appliance means you’re working around a gas line. A liner that’s stuck in a clay tile flue means you’re pulling with enough force to damage the tile if you don’t know what you’re feeling for. We’ve repaired chimneys where someone tried to save money by pulling their own liner, and the result cost more than the original replacement would have. If you’re seeing signs of liner failure, call us at (361) 314-3193. We’ll inspect it with a camera and show you exactly what’s going on before you spend a dollar.
FAQs
A properly installed DuraFlex 316L liner in the Dallas area should last 15 to 25 years, depending on appliance type and how often the fireplace gets used. Gas appliances run hotter and can shorten that life somewhat, while wood-burning fireplaces with regular cleaning tend to see the longer end. Our North Texas humidity and spring storm cycles contribute to corrosion at the cap and top section faster than in drier climates. Call (361) 314-3193 for a camera inspection and we’ll tell you what kind of remaining life your liner has.
Yes, in many cases. If the failure is at a single joint or a short section, we can often swap that segment rather than replacing the entire run. The decision comes down to what the camera shows. If the corrosion is isolated and the surrounding tube still measures within spec, we’ll tell you and quote the smaller repair. If the damage is widespread, a patch just delays the inevitable and costs more in the long run.
Most DuraFlex liner replacements in Dallas take four to six hours on site, start to finish. That includes removing the old liner, running the new tube, sealing the top plate and cap, and cleaning up. Larger chimneys or tricky access can push it to a full day. We’ll give you a real arrival window before we come out and the price is set before we touch anything.
We carry 4-inch, 6-inch, 7-inch, and 8-inch DuraFlex liner, couplers, and caps on our service vehicles when we head out to a known liner job. For unusual diameters or full replacements, we bring everything needed on the scheduled day so there’s no midpoint surprise. If you call ahead with your model information, we’ll arrive with the right parts.
Written by Nathan Corliss, Owner, Ashby Chimney Dallas at Ashby Chimney Dallas, serving Dallas and nearby areas.