Masonry repair
Sweep & inspection
Caps & crowns
Flue relining
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 Crown Repair: The Fort Worth Owner’s Guide
DuraFlex crown repair in Fort Worth typically runs $425 to $900 installed, and we do most crown work in a single visit. You’ll usually know it’s failed because you see a cracked or crumbling mortar cap at the top of the chimney, or water staining on the ceiling near the flue after a hard rain. DuraFlex liners themselves hold up well in North Texas, but the crown that seals the top of the chimney around that liner takes a beating from our freeze-thaw cycles and the summer heat that bakes the mortar until it shrinks and splits. The fix is straightforward when it’s caught before water gets behind the brick.
Which DuraFlex Models This Applies To
DuraFlex makes a family of chimney crown products, not just one part. The two you’ll most likely have in a Fort Worth home are the standard aluminum crown kit and the stainless crown kit, both sized to the liner diameter, not the brick opening. That’s the compatibility gotcha most people miss: a crown sized for the clay tile it’s replacing will be a full inch too wide, and no amount of sealant fixes a bad fit. We match the crown to the liner’s inside diameter – common sizes here are 5.5-inch, 6-inch, and 7-inch round – and then cut the crown to fit the chase top on site. DuraFlex’s OEM crown is what we use, because the factory bend radius matches the liner bead exactly. There are aftermarket aluminum crowns that’ll fit, but the savings is maybe $20 to $40, and the bead seat usually needs a small trim to sit flat. Not worth it.
Styles & brands we work with





Signs Your DuraFlex Crown Repair Is Failing
- Hairline cracks spidering across the crown surface. This is the first stage. Texas sun bakes the crown mortar, it shrinks, and micro-cracks open up. They let in moisture season after season until the cracks widen into channels.
- Chunks of mortar missing from the crown edge. Freeze-thaw in Fort Worth winters does this. Water seeps into a hairline crack, freezes, expands, and pops a chip off the corner. Once chunks start going, it’s a few seasons from structural failure.
- White chalky residue on the brick below the crown. That’s efflorescence, which is dissolved minerals leaching out of the masonry because water is traveling through the crown and down the brick face. It’s a visible record of every rain that got in.
- Water stains on the ceiling or wall near the fireplace after heavy rain. By the time you see this, water has made it from the crown, down the flue channel, and into the living space. The crown isn’t sealing the liner opening anymore.
- A rust line forming around the base of the DuraFlex liner where it exits the crown. That’s the metal cap losing its hold. The expansion and contraction of Fort Worth’s temperature swings works the seal loose, and once that bond breaks, water runs straight down the liner and into the firebox.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
In Fort Worth, a DuraFlex crown replacement at Flint Chimney Co runs $425 to $900 installed, and the price depends on two things: crown size and how much of the old crown can be salvaged. A straightforward 6-inch liner crown on a standard brick chimney is on the lower end. A larger chase top with a bigger crown pour, or a crown that’s fully failed and needs the old material chipped out to bare brick before we prep the surface, lands toward the higher end. Every quote includes the crown material – DuraFlex, which we stock – the removal of the old crown, the bonding adhesive, the crown pour, a new seal around the liner, and cleanup. You get the price in writing before we tool up, and the work carries our 365-Day Done Right Promise: if it fails within a year, we return and fix it at no charge. No argument, no revisit fee, just a call to (682) 255-2144.
DIY or Call Us?
You should not try to pour a crown yourself. This is the one part of the repair where doing it wrong doesn’t just look bad, it creates the exact problem you’re trying to fix. A crown has to slope away from the flue, maintain the right thickness at the edges, and bond to the liner at a specific angle or water pools against the liner and gets behind the seal. That said, you can absolutely do the diagnosis from the ground or a ladder with binoculars: check for the cracks, the missing chunks, the white residue I described above. If you spot any of those, call us at (682) 255-2144 and we’ll come out, get on the roof, take photos, and tell you exactly what we see and what it costs before anything gets touched. Hank Delano ran his early years of this trade on century-old chimneys in the Fairmount Historic District, and the rule then is the rule now: if it is not clean and it is not safe, we are not done.
FAQs
A properly poured DuraFlex crown here lasts 12 to 20 years, but the first hairline cracks can show up in as few as 6 to 8 years on chimneys that get full afternoon sun. Regular inspection and a crown sealer touch-up every few years pushes it to the long end of that range. Call (682) 255-2144 for a free estimate on a crown check.
Small hairline cracking can sometimes be sealed with a crown coat if the crown is otherwise intact and still slopes correctly. But if there are missing chunks, a rusted liner seal, or cracks wide enough to fit a dime, you’re looking at replacement, not patch. We’ll tell you plainly which one your chimney needs, and the estimate is free.
Most crown replacements are done in three to four hours, including removing the old crown and cleaning up. The new crown needs 24 hours to cure before it takes rain or heat, so we schedule work around the forecast when possible. Call (682) 255-2144 and we’ll give you a written price before we start.
We stock the common DuraFlex crown sizes for 5.5-inch, 6-inch, and 7-inch liners on our trucks, so most replacements happen same visit. If you have an oversized or unusual chase top, we order the matching crown and schedule the install within a few days. Along with DuraFlex, we also keep HeatShield and Gelco products on hand for related flue and seal work.
Written by Hank Delano, Owner, Flint Chimney Co Fort Worth at Flint Chimney Co Fort Worth, serving Fort Worth and nearby areas.