Chimney Flashing Replacement Seattle, WA

Chimney flashing replacement is the complete re-flash of a chimney: the old metal comes off, the mortar joint is cut fresh, and a new two-part system of step flashing and counter flashing is installed and sealed. It is the right call when the existing flashing is rusted through, has lifted away from the brick, was installed wrong in the first place, or has been caulked and re-caulked so many times that nothing is left to patch. James Chimney Sweep has handled this work across King, Pierce and Snohomish counties for more than 25 years.

This page is about starting over, not patching. If your flashing is basically sound and only needs a resealed seam or one re-bedded piece, our chimney flashing repair service is the lighter option. If the leak itself is the open question and you are not yet sure the flashing is to blame, chimney flashing leak repair is where that diagnosis happens. And chimney flashing installation covers brand-new chimneys or re-roofs where no usable flashing exists yet. Replacement sits between those: there is flashing on the roof, and it has reached the end of its useful life.

Our CSIA-certified technicians are licensed, bonded and insured in Washington, and we will tell you honestly when a repair would do and when replacement is the only fix that will actually hold through a Puget Sound winter.

Timing & Safety

When replacement is necessary and when a repair still makes sense

Replacement is the honest answer when:

• The metal itself has rusted through or is too thin to hold a seal
• Step flashing was never woven into the shingles, or counter flashing was glued to the face of the brick instead of set into the joint
• The same seam has been caulked repeatedly and the leak keeps coming back
• The flashing was bent, lifted or torn by ice, moss removal or foot traffic
• The roof is being replaced and the old flashing cannot be reused cleanly

A repair is usually enough when:

• The metal is sound and only one seam or corner has opened up
• The sealant has aged out but the lap and reglet are still correct
• A single piece of step flashing has shifted and can be re-bedded

We will not sell you a re-flash when a repair would hold. The flip side is just as true: a third sealant job on failed metal is money spent on a leak that is coming back.

Safety considerations

Flashing replacement is roof work done at the edge of a masonry structure, and we do not recommend homeowners attempt it. Wet Seattle roofs, moss and steep pitches make falls a real risk, and cutting a reglet into mortar without the right tools can loosen brick and create a bigger problem than the leak. Our technicians work with fall protection and the equipment the job calls for.

• Do not try to check or seal flashing from the roof yourself; look for interior signs and call us.
• Never apply roofing tar over existing flashing as a stopgap. It traps water, hides the real failure and has to be scraped off before replacement.
• If you see active dripping inside, place a container under it and move belongings. The fix happens on the roof, not from inside.
• A full re-flash is a good time to have the chimney cap, crown and flue checked. NFPA 211 recommends an annual chimney inspection, and the roof visit makes it easy to do both.

Seattle & Puget Sound conditions

Puget Sound weather is hard on chimney flashing in ways that make replacement more common here than in drier regions. Months of steady rain keep sealant wet, so caulk-only fixes break down fast and the leak returns the following fall. Moss grows under and around the step flashing, holding moisture against the metal and prying it up as it thickens; aggressive moss removal can bend the flashing further. Freeze-thaw cycles in the Cascade foothills and across Snohomish County push water into any lifted seam and widen it. Closer to the water, salt air accelerates rust on thin galvanized steel, which is why flashing in West Seattle, Tacoma, Edmonds and the islands often fails years earlier than the roof around it. When we replace flashing in this climate we pay attention to metal choice, a proper cricket on the upslope side, and a clean reglet so the new system is built for the region rather than just swapped like-for-like.