Gelco Chimney Cap Installation Nationwide

Gelco Chimney Cap Installation: The Bellevue Owner’s Guide

Gelco chimney cap installation in Bellevue typically runs $340-$620 for most single-flue residential setups, including the cap, flashing adaptation, and weatherproofing. We stock Gelco Series-A and Series-C caps in common Bellevue flue sizes - 8×12, 8×17, and 13×13 - and can usually install within 48 hours of inspection. Most Bellevue homeowners discover the problem after finding rust flakes in the firebox, water stains on the ceiling near the chimney breast, or hearing metal rattling during our windstorms off Lake Washington.

Call (425) 696-0387

Which Gelco Models This Applies To

Gelco caps fall into two product lines that matter for Bellevue homes: the Series-A galvanized line and the Series-C stainless line with the welded-seam hood. The Series-A carries a 10-year warranty and works fine for gas flues or occasional wood use; the Series-C steps up to lifetime warranty coverage and is what we spec for wood-burning fireplaces in neighborhoods like Lakemont and Woodridge where the flue sees heavy winter use.

To identify your existing cap, look for the stamped Gelco logo on the hood skirt and a spec tag on the mesh band showing the flue opening dimensions. If the tag’s corroded off, measure the flue tile opening precisely - Gelco caps are sized to the outside dimension of the flue tile, not the chimney crown. A 13×13 flue tile takes a 13×13 Gelco cap, but we’ve seen Bellevue homeowners order the 13×13 cap for a 13×13 crown and end up with a cap that sits on the mortar joint instead of the tile edge. That gap lets water run straight down.

We source Gelco caps through Haven’s buying network alongside DuraFlex and HeatShield materials. For most Bellevue replacements, the OEM Gelco cap is the right call. Aftermarket equivalents exist, but the mesh gauge and hood pitch rarely match Gelco’s rain-shed geometry, which matters here where we get 37 inches of annual rainfall concentrated October through April.

Signs Your Gelco Chimney Cap Is Failing

• Rust staining on the chimney crown or brickwork below the cap. Gelco Series-A caps use galvanized steel that eventually breaches at the weld points. Once the zinc layer fails, the steel underneath oxidizes fast in Bellevue’s marine air. We see this most on west-facing chimneys that catch the full brunt of weather coming off the lake.
• Water in the firebox after heavy rain. The cap mesh or hood has separated from the base band, or the base band itself has corroded through at the corners. Gelco caps use a crimped base band on Series-A and a welded base band on Series-C; the crimped version is the failure point in about 60% of the water-intrusion calls we get in Bellevue.
• Debris, leaves, or bird nesting material visible in the flue. The mesh sides have corroded open or the cap has shifted in wind. Bellevue’s bigleaf maples shed helicopters straight down uncapped flues in June, and once a squirrel gets in through a dime-sized mesh hole, you’re looking at a full flue obstruction.
• The cap is visibly tilted, shifted, or missing entirely. Gelco caps use either a screw-tighten base band or a outside-mount flange depending on the model. The screw-tighten version loosens through thermal cycling - hot flue, cold rain, repeat - and our freeze-thaw cycles in January and February accelerate the backing-out.
• Spalling brick or deteriorated mortar on the top course below the cap. Water is getting behind the cap and saturating the masonry. In Bellevue’s climate, that freeze-thaw damage moves fast; we’ve seen sound brick turn to powder in two winters when the cap drip edge wasn’t shedding water clear of the crown.

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Replacement Cost & What’s Included

The range depends on three things: cap series, whether the existing base band is seized and needs cutting off, and whether the crown underneath needs resealing before the new cap goes on. We don’t guess at this. Our tech brings the camera, documents the crown condition, and delivers a written price before any work starts - Haven Standard Clause 1. Every Gelco cap we install carries the 365-Day Done Right Promise: if it leaks, shifts, or fails, we make it right.

DIY or Call Us?

There’s a safe middle ground here. You can check whether your cap is loose by sight from the ground with binoculars, and you can measure your flue tile opening from inside the firebox with a tape measure if you’re comfortable on a step stool. What you should not do is climb a wet roof in Bellevue’s fall and winter conditions to tighten screws or swap a cap yourself. The slope, the moss, and the height combine badly; we’ve been called to homes where the homeowner made it up but couldn’t make it down, or where a dropped tool punched through a skylight.

If the cap’s accessible from a low-slope section and you’re experienced on ladders, a Gelco screw-tighten replacement is mechanically simple. But getting the base band square, the mesh tension even, and the drip edge projecting past the crown takes a practiced hand. Most of our Bellevue calls for Gelco cap installation come from homeowners who tried the swap, discovered the old base band was rust-welded to the flue tile, and called us to finish without damaging the flue. The camera doesn’t guess. Neither do I. Call (425) 696-0387 and we’ll price it in writing before we start.

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