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 Boston: What to Know First
Gelco chimney cap and crown work in Boston typically runs $340-$1,200 depending on whether we’re rebuilding a spalled crown, replacing a single-flue cap, or fabricating a custom multi-flue solution. Most jobs are completed in one visit once parts are on hand, and every quote is written before any work begins. If you own a Gelco cap or crown and it’s showing rust, cracking, or pulling away from the flue, call (857) 567-8887 for a documented inspection and a firm price. This page is for Boston homeowners who want to know exactly what’s wrong, what it costs, and what the fix actually involves before a technician sets foot on the roof.
How Gelco Products Fail - and How We Fix Them
Gelco makes solid chimney caps and crowns, but Boston weather finds the weak points in any exterior metal. Here’s what we actually see on rooftops across Dorchester, Jamaica Plain, and the South End:
- Gelco stainless steel single-flue caps: mesh screen pull-away at the base collar. On older Gelco caps the screen is spot-welded to the skirt, and ten years of freeze-thaw cycles in Boston’s damp air loosens those welds first. The cap still looks fine from the ground, but birds and squirrels get in. We re-secure or replace the screen; if the cap body is sound, the screen replacement runs $90-$180.
- Gelco multi-flue caps: cross-brace mounting brackets on the center seam. The wider the cap, the more it flexes in nor’easter winds, and Gelco’s center-seam brace is the first thing to fatigue. Rust streaks down the crown point to it. We install reinforced stainless brackets and re-seal the seam, which runs $220-$380 depending on cap width.
- Gelco crown flaking: porous concrete that wasn’t sealed at install. This is the big one we see on Boston triple-deckers built before 1990. Water sits on the crown, seeps into the concrete, freezes, and spalls the surface. A crown that’s flaking is a crown that’s eroding. We grind and recoat or rebuild it, typically $500-$900 for a standard single-flue crown; larger multi-flue crowns run higher.
- Gelco cap legs corroding at the base where they meet the flue tile. Cheap aftermarket caps use galvanized legs that rust where condensation collects. If you’ve got a Gelco cap, the stainless body usually outlives the mounting hardware. We replace with proper stainless legs and re-mount, $140-$260.
- Rust bleeding from a Gelco cap that’s been on the chimney 15+ years. If the cap body itself is corroded, replacement is usually cheaper than trying to stop rust that’s already through the metal. New Gelco or equivalent single-flue caps run $280-$450 installed; multi-flue $600-$1,100. We’ll show you the old cap and the new one side by side in your photo record.
Our Gelco Chimney Cap & Crown Process

Every Gelco job we do in Boston follows the same sequence, and you’ll see the evidence at every step:
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You call, a live person answers, and we schedule the inspection. We confirm what we’re looking at, what to expect, and text you the day of arrival with a named technician.
- 2
Camera-scan inspection of the flue and cap from the roof. Clause 4 of the Haven Standard requires a documented photo record on every job. You see the rust, the crack, the pulled screen - not a verbal description.
- 3
Written scope and firm price delivered before any work starts. No exceptions. You approve the number in writing; we don’t start without that.
- 4
Parts decision: OEM Gelco or equivalent aftermarket where it’s actually better. For the cap body, we source Gelco or DuraFlex stainless. For mounting hardware and screens, we sometimes use heavier aftermarket parts that hold up longer in Boston weather. We’ll explain which and why on your quote.
- 5
Repair or replacement, plus crown work if needed. We secure the cap, re-point the crown wash if it’s cracked, and seal the interface with high-temp silicone rated for outdoor exposure.
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After photo record and written warranty. You get every image from the job, a written description of what we did, and the 365-Day Done Right Promise stamped on the work. If it’s not right, we make it right.
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Here are the numbers we quote most often on Gelco work in Boston:
- Single-flue stainless cap replacement: $280-$450
- Multi-flue cap replacement: $600-$1,100
- Crown repair with sealed recoat: $500-$900
- Crown replacement (tear-out and rebuild): $800-$1,500
- Custom cap for unusual flue dimensions or multi-flue setups: $900-$2,500
What moves the price: roof access (steep pitch, slate, height), whether the crown needs full replacement versus recoat, and whether we’re doing the work on a single-flue or multi-flue chimney. Every quote is written and itemized before we start. Call (857) 567-8887 for a free estimate on your Gelco cap or crown. If you have another company’s written quote, bring it - we’ll give you a free second opinion.
Why Boston Homeowners Call Level Two Chimney Boston for Gelco Work

We’ve inspected and cleaned more than 38,000 chimneys since 2009, and a good share of those rooftop exams in Boston turn up Gelco caps and crowns in some stage of wear. Our technicians know the difference between a cap that needs a $90 screen repair and a crown that’s about to crumble into the flue. When a Gelco part isn’t the right call, we work with DuraFlex and HeatShield components too, and because we buy through the Haven purchasing network, we keep parts pricing honest. Every tech is background-checked and uniformed, license number on the page, and when we say we’ll be there, we’re there. Corrine Halstead, our owner, built this crew around one rule: hand the customer a written scope and a firm price before anything happens on the roof. The camera doesn’t guess. Neither do we.
FAQs
Gelco makes a capable mid-grade stainless cap, and they’re common on Boston chimneys, but their long-term weak point is the screen attachment and the mounting hardware, not the cap body itself. We’ve replaced dozens of Gelco caps where the stainless body was fine but the legs or mesh had failed. We stock or source Gelco and comparable DuraFlex parts and will tell you honestly which is the better value for your chimney.
Yes, if the cap body is solid. The most common Gelco repairs we do in Boston are re-securing the mesh screen, replacing corroded mounting legs, and re-sealing the base. If rust has gone through the metal, repair usually isn’t worth it - a new cap costs less than chasing corrosion for another season. We’ll show you photos of the cap from the roof and the options before asking you to spend anything.
Ten to fifteen years on average, but the mounting hardware often fails before the cap body does due to Boston’s freeze-thaw cycle and salt air in coastal neighborhoods. If you’re seeing rust streaks on the crown or hearing animal noise in the flue, it’s usually a hardware or screen issue that doesn’t require a full cap replacement. Get it looked at now, before water works its way into the flue liner.
Yes. Every Gelco cap or crown repair we complete carries the 365-Day Done Right Promise: if the work we did isn’t right within a year, we come back and make it right at no charge. You’ll have that in writing on your job record before we leave.
We’re an independent Gelco service provider, not a manufacturer-authorized dealer, which means we’re not locked into selling you Gelco parts when another brand is a better value. We source Gelco, DuraFlex, and HeatShield materials and choose what’s best for your chimney and your budget. The written quote you approve is the price you pay - no manufacturer incentives, no add-ons after the fact. Call (857) 567-8887 to get the process started.
Written by Corrine Halstead, Owner, Level Two Chimney Boston at Level Two Chimney Boston, serving Boston and nearby areas.





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