Sweep & inspection
Caps & crowns
Flue relining
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 Chimney Cap Installation: The Fresno Owner’s Guide
DuraFlex chimney cap installation in Fresno typically runs $240 – $460 installed when paired with an existing DuraFlex liner system, and we stock the common sizes on the service van so the swap usually happens same-visit. The cap is the first line of defense for your entire DuraFlex system, and when it fails, you’ll usually notice it after a rainy week or during the first burn of October: water streaks near the firebox, rust flakes on the hearth, or a draft you can’t explain. DuraFlex caps are aluminum or stainless, sized to the liner diameter, and when they’re loose or corroded they compromise everything below them.
Which DuraFlex Models This Applies To
DuraFlex makes its chimney caps as part of a matched liner system. That means the cap fits the liner, not the chimney, which matters more than most homeowners expect. Common sizes we install run from 4-inch to 8-inch inner diameter, and the cap clamps to the liner top using a hose-clamp style band. The gotcha: a 6-inch DuraFlex liner needs a 6-inch DuraFlex cap, and while a generic 6-inch cap can physically sit on top, the clamp profile and weather seal won’t match, so it works loose within a season or two. We see that on a lot of homes across Fresno, from Clovis-adjacent neighborhoods to the newer builds up near Woodward Park.
DuraFlex marks the liner size on the top few inches of the flex tube and on the original install tag. If the tag is long gone, we measure the inner diameter at the cap base before quoting, so you’re not guessing. We install DuraFlex OEM caps by default because the clamp is engineered for the liner profile, but we also carry Copperfield and Gelco stainless caps when a customer wants a heavier gauge or a different screen rating. All of them get the same written install price before we start. Alcott Chimney Fresno is an independent service provider and not affiliated with DuraFlex. We simply stock their parts because they’re what we’ve been installing since 2002.
Styles & brands we work with





Signs Your DuraFlex Chimney Cap Installation Is Failing
- Water staining around the firebox or on the ceiling near the flue. Usually means the cap’s rain deflector has rusted through or the seal at the liner top has failed, and California’s winter rain is getting past it. The stains show up weeks after the weather does.
- Rust flakes or metal crumbs on the smoke shelf during a sweep. The cap screen corrodes from creosote and condensation long before the liner does. If the upper third of your liner is clean but the cap is shedding, the cap is eating the weather.
- A loose cap that rattles in a strong Fresno wind. The clamp band stretches over time from heat cycling, especially on east-west facing flues that get full sun on one side. Once the cap moves, it galls the liner top and the fail accelerates.
- You hear birds or small animals inside the chimney in spring. The cap screen is either torn or the cap has shifted enough to leave a gap. In Fresno this usually means starlings, and they build fast.
- Draft problems on days with no wind, or smoke backing into the room at ignition. A partially blocked cap screen restricts airflow across the firebox, and an undersized cap from a previous handyman job does the same thing from day one. Duct tape and hardware-store caps are common culprits on older Tower District craftsman homes.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
A DuraFlex chimney cap installation in Fresno typically runs $240 – $460 installed. The spread depends on cap size, whether we’re matching a stainless or aluminum OEM cap, and whether the liner top needs a clean-up cut before the new cap seats. Most homes fall in the $280 – $340 range for a 6-inch stainless DuraFlex cap. The price includes the cap, the liner-top prep, the new clamp band, and a water-tight inspection at the roof line before we come down. You get a written price before any work starts, and the installation is covered by our 365-Day Done Right Promise: if the install fails within the year, we come back and fix it free. That matters in Fresno because summer heat aging and winter rain plus valley fog are hard on cap hardware, and a guarantee isn’t worth much if it doesn’t specifically cover both.
DIY or Call Us?
You can safely do a ground-level check: grab binoculars and look for a tilted cap, a pulled-away clamp band, visible gaps, or a screen clogged with creosote or nesting material. Write down what you see before you call, because it helps us bring the right parts the first trip. What you should not do is get on a roof with a screwdriver and a hardware-store cap. Roof falls are the most common serious injury we see in this trade, and a poorly clamped cap on a DuraFlex liner will fail within two seasons and take the liner top with it. If your chimney is steep, a second-story pitch, or you just don’t want to climb, call (559) 215-1714 and we’ll handle it. Tell me what you’re seeing and I’ll tell you what it actually means.
FAQs
A stainless DuraFlex cap installed correctly typically lasts 10 to 15 years in the Central Valley, while aluminum versions average 7 to 10. Our Fresno heat plus the valley’s damp winter fog eat aluminum faster than most of the country, so if you’re replacing one this year, we’ll quote you stainless first and show you the price difference before you commit. Call (559) 215-1714 for an exact quote on your liner size.
Usually no. Once a DuraFlex cap shows rust-through on the deflector or the screen starts tearing at the clamp line, replacement is the honest fix and repair just delays the same cost by a few months. If the only issue is a loose clamp, we can often re-seat the existing cap and re-tension the band for a fraction of a full replacement. We’ll tell you which one you have after looking at it. Call (559) 215-1714 and we’ll assess it without pushing a swap you don’t need.
A straightforward DuraFlex cap replacement takes about 45 minutes on a single-story roof, including liner-top inspection and the water check at the end. The longest part is honestly setting up safe ladder access on uneven ground or older roof surfaces. You’ll have the old cap and the invoice in hand before we load up.
We stock the common 4, 6, and 8-inch stainless DuraFlex caps on the van, along with Copperfield and Gelco equivalents. The less common diameters are usually a two-day order. The reason we ask about your liner size when you call is so we can bring the right one the first trip. Call (559) 215-1714 with your liner size or a photo of the tag, and we’ll confirm exactly what’s on board before we schedule.
Written by Ruben Castellano, Owner, Alcott Chimney Fresno at Alcott Chimney Fresno, serving Fresno and nearby areas.