Level 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.
Gelco Chimney Cap & Crown in Fairfax: What to Know First
We repair, replace, and install Gelco chimney caps and crowns throughout Fairfax, typically completing most cap jobs in a single visit once the existing cap is off and measured. A standard Gelco cap replacement in Fairfax runs $340 to $620 installed, while crown repair or coating work spans $450 to $1,100 depending on how much of the existing crown is salvageable. Every quote is written before any work starts, and you walk away with photos of exactly what we found and what we did.
This page is for Fairfax homeowners who already have a Gelco cap on their chimney or are weighing Gelco against other options and want to know how these particular products hold up in Northern Virginia weather. If you’re trying to figure out whether the cap on your roof is actually a Gelco or whether that cracked crown needs attention this season, the sections below name what we see in the field and what it costs to correct. Call (571) 443-8256 and one of us will walk you through it.
How Gelco Products Fail - and How We Fix Them
- Gelco 12×12 single-flue caps: leg breakage at the clamp band. The stamped aluminum legs that grip the flue liner are the first thing to go on Gelco’s standard single-flue caps. We see it on chimneys all over Fairfax, because the legs are the thinnest metal on the entire cap. Wind loading against the hood flexes those legs at the clamp screw until they snap clean off, usually on the prevailing-weather side. The fix is a replacement cap with heavier-gauge legs or, where the flue is square and standard, installing a Gelco cap with stainless legs, which Gelco does make for its mid-range line. We stock both and decide based on what the camera shows of the flue opening.
- Gelco multi-flue caps: screen blow-out from creosote-loaded exhaust. The stainless mesh screen on Gelco multi-flue caps is fine for gas, but on wood-burning chimneys in older Fairfax homes, we regularly find the screen clogged with glazed creosote and then bowed outward like somebody kicked it from inside. That’s not an animal; it’s years of hot exhaust and rain cycling against built-up creosote until the screen welds to itself and tears away from the frame. We replace the screen when the frame is sound, reattach it with mechanical fasteners rather than the original spot welds, and tell you whether the creosote load behind it means a sweep should happen sooner than your usual schedule.
- Gelco chase covers with pre-welded cap bases: failing at the weld seam. On prefab chimney systems across Fairfax, Gelco chase covers sometimes arrive with the cap base factory-welded to the cover pan. That weld is aluminum on aluminum, and in a climate that freezes and thaws forty nights a winter, the seam cracks along the heat-affected zone. Water doesn’t pour through, it seeps, so it takes a few seasons to show up as rust on the chase top or a water stain on the ceiling below. When we find this, we replace the entire cover-cap assembly rather than trying to patch a cracked weld with silicone, because the next crack is already started.
- Gelco crown products on masonry chimneys: coating separation at the flue tile edge. Crown issues on Gelco-branded or Gelco-capped masonry chimneys tend not to be Gelco failures at all, they’re crown failures at the point where the flue tile exits the crown. The mortar cap around the flue tile shrinks and pulls away over a Fairfax season, and rain gets into that annular gap. If a Gelco crown-coating product was applied over a cracked substrate, the coating simply cracks in the same place a year later. We don’t coat over moving concrete. We evaluate the crown, build up the low spots, then apply the coating only after the substrate is stable, and photograph every layer so you can see what didn’t get painted over.
- Gelco custom caps: wrong flue measurement leading to half-hanging hoods. Most failed Gelco custom caps we see in Fairfax were ordered by someone who measured the flue liner, not the flue opening, or measured only one dimension on an irregular flue. A cap sized that way leaves a gap on the wind-ward side wide enough for rain to drive in, and the owner’s left with a $600 cap that functions like a $40 hole cover. We measure the flue interior with a digital caliper, note any out-of-square variance, and order or fabricate the cap to the actual opening. That’s true whether it’s a Gelco or any other brand.
Our Gelco Chimney Cap & Crown Process

- 1
Call or text. You reach a person, tell us what’s going on with the cap or crown, and we book a window that works for you.
- 2
Camera down the flue and a look at the crown. Before anything else, Corrine or one of our techs documents the flue interior and the condition of the crown. You get the photos; they’re yours.
- 3
Written quote with the price you pay. We measure the flue or crown, decide between OEM Gelco and equivalent aftermarket parts, and put the full number in writing. The price doesn’t change when we’re on the roof.
- 4
The work. Old cap off, crown prepped, new cap or crown coating installed per the manufacturer’s spec. When the existing part can be repaired, we say so instead of selling you a part you don’t need.
- 5
Photo record and test. We test cap fit and crown drainage, then photograph the finished job. You get a written record of what was done, the price you paid, and what we warrant.
- 6
365-Day Done Right Promise. If the cap or crown fails within a year of our repair, we make it right under the Haven Standard. No negotiation, no fine print.
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AfterWhat Gelco Chimney Cap & Crown Costs in Fairfax
- Gelco single-flue cap replacement: $340 to $520 installed, depending on flue size and leg style
- Gelco multi-flue cap replacement: $500 to $880 installed
- Gelco custom cap fabricated to fit: $690 to $1,300 installed
- Crown repair and coating on a standard masonry chimney: $450 to $1,100
- Chase cover and cap replacement (prefab): $580 to $950
What moves the price in Fairfax is the flue dimensions, the condition of the crown beneath the cap, and whether the existing chase cover or crown can be salvaged. We don’t charge a trip fee just to look, and every quote includes the photo record, the written warranty, and our 365-Day Done Right Promise under the Haven Standard. Call (571) 443-8256 for an exact number on your chimney.
Why Fairfax Homeowners Call Level Two Chimney Fairfax for Gelco Work

We’re an independent Gelco service provider, not a manufacturer arm, which means we have no incentive to sell you a part you don’t need and no reason to skip the photo documentation. We’ve been camera-first since 2009, and Clause 4 of the Haven Standard requires a documented photo record on every job. Clause 1 requires a written price before any work starts. That combination is why homeowners who research before they call tend to end up on the phone with us.
Our techs know Gelco caps and crowns because Fairfax keeps giving us reasons to. The flue sizes on older colonials near the Fairfax County Government Center corridor are almost a study in out-of-square liners, and the freeze-thaw cycle here exposes cap and crown defects faster than a milder climate. When a job calls for a liner or a repair component outside Gelco’s range, we carry DuraFlex and HeatShield materials through our Haven buying network, so you’re not waiting on a backorder and you’re not paying markup on a part we had to source retail.
FAQs
Yes. We measure the actual flue opening with a digital caliper and either order the correct Gelco unit or fabricate a custom cap to the millimeter, so the hood sits centered over the flue and fully covers the opening on all sides. Call (571) 443-8256 and we’ll come measure.
We use both, and we’ll tell you which we’re quoting and why. OEM Gelco parts are specified when the cap is under warranty or the exact match matters cosmetically; quality aftermarket parts with heavier-gauge legs or stainless screens are used where Gelco’s stock aluminum leg design has already failed once and will fail again. Either way, the price and the part number are in writing before work starts.
Not necessarily. If the frame is intact, we remove the damaged screen, clean the mounting channel, and reattach a new screen with mechanical fasteners rather than the original spot welds, which is the most common failure point on Gelco multi-flue caps. If the frame itself is bowed or cracked, a replacement is the honest call, and we’ll show you the photo before you commit.
Most Gelco cap replacements and crown repairs are scheduled within one to two weeks, faster during the spring when we’re not pushing against freeze-thaw jobs. We don’t promise same-day dispatch because we won’t book a job we can’t keep. Call (571) 443-8256 and you’ll speak with a live person who can tell you our next open window.
Every Gelco cap or crown job includes before and after photos of the flue, cap, and crown, the written scope, the written price, and the written warranty, per Clauses 1 and 4 of the Haven Standard. You’ll have a record you can show to a home inspector, a buyer, or anyone else down the road.
Written by Corrine Halstead, Owner, Level Two Chimney Fairfax at Level Two Chimney Fairfax, serving Fairfax and nearby areas.





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