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 Miami Owner’s Guide
DuraFlex crown repair in Miami typically runs $425 – $780 installed, depending on the crown’s condition and whether we’re sealing, resurfacing, or rebuilding it from the chase top down. We stock DuraFlex-compatible crown materials on our trucks and can complete most crown jobs in a single visit. Most owners discover the problem the hard way: a water stain on the ceiling near the fireplace, or a chunk of crown mortar sitting in the yard after a hard Miami storm.
The crown is the concrete or mortar cap that sits on top of your chimney chase and sheds water away from the flue. When it cracks, water gets behind the DuraFlex liner chase and starts working on everything below it. What starts as a hairline crack turns into spalling, and in Miami’s wet season, the damage compounds fast.
Which DuraFlex Models This Applies To
DuraFlex crown repair applies to any chimney system running DuraFlex stainless steel liner inside a masonry or framed chase. We work on DuraFlex 304 and 316Ti liner installations, both single-wall and smooth-wall configurations, and the crown work is the same either way: we’re sealing the top of the chase, not the liner itself.
Here’s the compatibility detail most Miami owners miss: your crown isn’t actually a DuraFlex part. DuraFlex makes the liner system. The crown is site-built or site-cast by the installer. So when a crown fails, the fix is about matching the crown material and sealant to the chase dimensions and the DuraFlex top plate you already have. We measure the chase opening, verify the top plate size, and cut the new crown to match. If you have a multi-flue chase, that’s a bigger crown form and a higher material cost. We’ll show you the measurements before we pour or patch.
For aftermarket parts, we use professional-grade crown materials from the same trade brands we trust on every job: DuraFlex for liner components, plus HeatShield and Gelco for crown sealants and repair products. Flint Chimney Co Miami is an independent service provider, not affiliated with DuraFlex directly, but we install and repair their systems every week.
Styles & brands we work with





Signs Your DuraFlex Crown Repair Is Failing
- Water stains on the ceiling or wall near the chimney. This means water is getting past the crown and running down inside the chase. By the time you see the stain, the crown has likely been leaking for months.
- Efflorescence on exterior masonry. That white, chalky residue is salt being pushed out of the brick or block as water moves through it. It tells you water is inside the structure, and the crown is the most common entry point in Miami rains.
- Cracked or spalled crown surface. If you can see cracks wider than a dime, or chunks of crown material have broken off, the crown has lost its water-shedding ability. Miami’s heat-and-rain cycle makes this worse: hot sun expands the material, sudden downpours cool it fast, and the thermal shock widens cracks.
- Rust staining at the top of the DuraFlex liner or top plate. Water sitting on the crown surface promotes rust at the liner connection. If you see orange streaks below the crown line, water has been pooling there.
- Damper rust or difficulty opening. Water that gets past the crown runs down the flue and settles at the damper. A rusted damper in a Miami home with no other water source is usually a crown problem.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
In Miami, a standard single-flue DuraFlex chase crown repair runs $425 – $580. A full crown recast with new forms runs $600 – $780. Multi-flue chases or heavily damaged chase tops can push toward $900, but we’ll give you the exact number in writing before we touch anything.
| Service | Typical Miami Price Range |
|---|---|
| Crown crack repair and reseal | $425 – $580 |
| Full crown recast (single flue) | $600 – $780 |
| Multi-flue crown recast | $750 – $900+ |
| Chase top replacement (if crown too far gone) | $650 – $950 |
Every crown repair includes the materials, labor, cleanup, and a written inspection report with photos. The 365-Day Done Right Promise covers the full repair for one year: if the crown fails again within that window, we come back and fix it at no charge. That’s not a verbal promise. It’s in writing, on every invoice.
DIY or Call Us?
You can safely do one thing yourself: look at the crown. If you can see it from the ground or a ladder without getting on the roof, check for visible cracks, missing chunks, or standing water after rain. Take a photo. Send it to us or just describe it over the phone. That’s all we need to give you a ballpark.
What we don’t recommend is getting on the roof with a bucket of sealant. Crown repair done wrong traps water instead of shedding it, and you won’t know until the ceiling stains show up months later. Our crews have the right materials, the right forms, and the right safety gear for roof work in Miami conditions. And if you’ve already got water damage behind the crown, we’ll find it before we seal anything, not after.
Call (786) 305-7861. Tell me what you saw, I’ll tell you what it costs.
FAQs
A properly poured crown with the right sealant should last 15 – 20 years in Miami’s climate, but hairline cracks can appear inside 5 years if the original installer used standard mortar instead of a proper crown mix. We see that a lot on older Coral Gables homes and Brickell high-rises where the original build used whatever was on the truck. If your crown is cracking early, it’s usually the material that failed, not the weather.
Small cracks under a quarter-inch wide can usually be cleaned and resealed with Gelco crown repair products, which is the $425 – $580 range. If the crown is spalling, missing sections, or showing multiple wide cracks, a full recast is the honest fix. We’ll tell you which one you need and show you photos of the damage before you approve anything.
Most single-flue crown repairs are done in 3 – 4 hours, including setup, removal of the old material, repour or reseal, and cleanup. A full recast on a multi-flue chase can take most of a day. We’ll give you a time window before we schedule, and the crew shows up inside it.
We stock crown forms, sealants, and DuraFlex-compatible top plates on our trucks. For unusual chase sizes, we’ll order the exact part and come back, but the common sizes we carry are ready to go. Call (786) 305-7861 for a free estimate, and we’ll tell you what’s in the truck for your specific setup.
Written by Hank Delano, Owner, Flint Chimney Co Miami, serving Miami and nearby areas.