Chimney Flashing Repair Cost in Seattle (2026 Pricing & When to Replace)

The Real Source of Most "Chimney Leaks"

When a Seattle homeowner calls us about water stains on a living-room ceiling near the fireplace, roughly nine times out of ten the problem isn't the chimney itself — it's the flashing. Flashing is the layered metalwork that seals the joint between the chimney and the roof. It's the single most vulnerable waterproofing detail on a pitched roof, and in a climate with 152 rain days and steady southwest winds driving water sideways, it's the first thing to fail.

This 2026 guide covers every kind of flashing repair, real Seattle-area pricing, the difference between a $300 reseal and a $2,500 rebuild, and the material choices that actually make sense for the Pacific Northwest.

What Is Chimney Flashing and Why Does It Matter

Flashing is a system of three (sometimes four) metal layers that work together to shed water off the chimney and onto the roof:

• Step flashing — small L-shaped pieces that tuck under each course of shingles and up the side of the chimney.
• Counter flashing (cap flashing) — a second layer embedded into a mortar joint on the chimney that folds down over the step flashing, creating a watertight overlap.
• Apron flashing — the front piece that sits on the downhill side of the chimney where water hits first.
• Saddle / cricket — a small peaked structure on the uphill side of wider chimneys that diverts water around the chimney instead of letting it pool.

When any of these components fails — because of rust, sealant failure, lifted nails, wind damage, or simple age — water bypasses the system and travels down the chimney inside the wall cavity. The results show up as ceiling stains, attic mildew, rotted framing, and eventually full drywall failure. See our in-depth article on why chimneys leak when it rains for the full diagnostic breakdown.

7 Signs Your Chimney Flashing Is Failing

• Water stains on ceilings or walls near the fireplace, especially after wind-driven rain.
• Visible gaps between the flashing and the chimney or roof.
• Lifted, curled, or bent metal — often after a windstorm.
• Failed or missing sealant (old caulk cracked, pulled away, or absent entirely).
• Rust staining on the chimney or roof below the flashing.
• Debris and moss buildup trapped behind the flashing — holds water against the metal 24/7.
• Attic moisture around the chimney chase — mildew, water-darkened framing, or dripping during storms.

If you're seeing any of these, don't wait for the next storm. Book a chimney inspection and get a clear picture of what's happening before the damage reaches the ceiling.

Types of Flashing and When Each Is Used

A properly built chimney has all four where the roof geometry calls for it. A builder-grade job often has step and apron only, caulked to the chimney with no real counter flashing — a setup that leaks in 5-10 years in Seattle rain.

2026 Chimney Flashing Repair Cost Breakdown (Seattle)

The number on your invoice depends on what's failing and how much has to be replaced. Here's the 2026 Seattle range:

For a specific number on your roof and chimney, book a free same-day estimate. We photograph the flashing from every angle and send a written quote so you know what's being replaced and why.

Why Seattle Flashing Fails Faster Than the National Average

The National Association of Home Builders estimates flashing should last 20-30 years. In Seattle, plenty of flashings fail at 10-15. Three reasons:

Constant saturation + UV cycling

152 rain days, then summer UV baking the sealants dry, then another wet winter. Standard roofing caulks that last 15 years in Denver last 5-7 in Seattle. Every inch of exposed sealant has to be properly detailed — or better, designed out of the system entirely with real counter flashing that doesn't depend on caulk.

Wind-driven rain from the southwest

Our dominant storm pattern drives rain sideways against the south and west sides of chimneys. Flashing laps that are fine with vertical rain leak under pressure-driven rain. This is why north-facing flashing often looks fine after 20 years while the south-facing side is failing after 10.

Dissimilar metals corrosion

Aluminum flashing in direct contact with galvanized nails, or copper flashing meeting an aluminum apron, accelerates corrosion in wet climates. Seattle has the moisture; the chemistry does the rest. Good installers match metals throughout; cheap installers mix them.

Flashing Materials Compared: Aluminum vs. Lead vs. Copper vs. Galvanized

Galvanized steel

Cheapest option. Rusts through in 15-25 years in Seattle. We only use it on budget-constrained repairs where the client understands the shorter lifespan.

Aluminum

The Seattle workhorse. Won't rust, reasonably priced, easy to form, lasts 25-40 years when properly detailed. Doesn't like direct contact with wet concrete or copper. Our default for most repair and rebuild jobs.

Lead

The historic standard, still the highest-performing material for counter flashing specifically — it conforms perfectly to irregular masonry and lasts 50-100 years. More expensive and slower to install. We use it on historic homes in Capitol Hill, Queen Anne, and Madrona where matching period materials matters.

Copper

The top-tier option. 75-100+ year lifespan, develops a beautiful patina, and pairs well with premium roofs. Expensive — $400-$900 premium over aluminum. Worth it on homes where the owner plans to stay 20+ years or on high-end architectural projects.

When You Need a Chimney Cricket

A cricket (also called a saddle) is a small peaked roof structure behind the uphill side of the chimney. Its job is to divert water and debris around the chimney instead of letting them collect against the back wall. The International Residential Code requires a cricket on any chimney wider than 30 inches measured along the roof.

In practice, we see three situations where a cricket is missing but should be there:

• Pre-2006 construction when the requirement wasn't enforced consistently in King County.
• Owner-built or remodel chimneys where the builder skipped the detail to save labor.
• Re-roofs where the original cricket was torn off and not reinstalled.

Symptoms of a missing or undersized cricket include pooled water on the uphill side, heavy debris collection against the chimney, rotted roof deck above the chimney, and recurring leaks at the back corners of the chimney no matter how many times the flashing is resealed.

A proper framed-and-flashed cricket installation in Seattle runs $600-$1,800 depending on chimney width, roof pitch, and material. It's frequently the single most impactful repair we do on problem leaks.

Repair vs. Full Replacement: How to Decide

When we inspect flashing, the decision tree looks like this:

• Reseal only — if the metal is sound, flat, properly lapped, and the only failure is dried-out caulk at the counter-flashing reglet. Buys 3-7 years. Cheapest option.
• Partial replacement — if one side of the flashing (usually the south or southwest-facing side) has failed but the rest is fine. Common in 15-25-year-old homes.
• Full replacement — if the flashing is galvanized and rusting, if the counter flashing was never properly installed, if it's been caulked over 2+ times, if the step flashing is face-nailed (a major red flag), or if the chimney was just rebuilt/repaired. This is also the right call when you're doing a larger chimney repair and the flashing is already disturbed.

Reseal-only is tempting because it's cheap, but if the underlying metalwork is failing, you're renting time, not solving the problem. Our estimators will tell you honestly when a reseal is enough and when it's throwing money away.

The Flashing Installation Process

A proper full flashing replacement unfolds roughly like this:

• Roof setup: roof jacks, safety harness, tarps to protect the rest of the roof.
• Demo: shingles around the chimney lifted, old flashing removed, old sealant cleaned off the masonry. Existing mortar joint for counter flashing chiseled out to depth.
• Cricket framing (if needed): 2x lumber framed on the uphill side, sheathed, wrapped in ice-and-water shield membrane.
• Step flashing: L-pieces bent to exact roof pitch, nailed to the roof deck (never the chimney), woven under each shingle course.
• Apron flashing: wraps the downhill side and over the first course of shingles.
• Counter flashing: inserted into a freshly cut/chiseled mortar joint (the reglet), locked in with lead wedges or mortar, folded down to cover the step flashing by at least 2 inches.
• Sealing: top edge of counter flashing sealed with high-quality polyurethane or modified-silicone sealant. Shingles relaid with new roofing nails.
• Waterproofing: on jobs pairing flashing with chimney waterproofing, the masonry is sealed with a breathable siloxane after flashing cures.

A full flashing rebuild on an accessible single-story roof takes 6-10 hours. Multi-story, steep-pitch, or cedar-shake roofs can push it to 1.5-2 days.

How to Prevent Future Flashing Leaks

• Inspect annually. Add flashing to your yearly fall chimney maintenance checklist.
• Clear moss and debris off the flashing every spring — moss holds moisture and eats through sealant.
• Replace sealant proactively every 5-7 years on aluminum flashing, even if it looks fine.
• Never let a roofer reuse old flashing on a re-roof. It almost always costs you a leak within 2-3 years. Insist on new flashing as part of any re-roof around the chimney.
• Pair flashing work with chimney waterproofing — the masonry and the metalwork fail together because they face the same weather.
• Add or upgrade a cricket on any chimney wider than 30 inches, even if the code didn't require it when the house was built.

Get a Flashing Quote From a Licensed Seattle Contractor

Flashing is specialized work. The difference between a properly built counter flashing with a chiseled reglet and a contractor simply caulking a piece of metal to the chimney face is decades of service life. Before signing a quote, ask:

• Are you removing the old flashing completely, or flashing over it?
• Will the counter flashing be embedded in a mortar reglet, or surface-mounted?
• What metal — aluminum, lead, copper — and what gauge?
• Is a cricket required on my chimney, and is it included?
• Are shingles around the chimney being replaced or re-laid?
• What's the warranty on labor and materials?

Seattle Chimney Pros has rebuilt chimney flashings on over 2,500 homes since 2011, from Tacoma ranches to Queen Anne Victorians and modern Bellevue hillsides. Call (253) 429-8006 or request a free estimate. We'll photograph the existing flashing, walk you through exactly what's failing, and quote a repair or full rebuild that matches your chimney and your budget. For details on the service itself, see our chimney flashing repair page or get a direct flashing repair quote.