Chimney Cap Installation & Replacement Seattle, WA

A chimney cap is the metal cover that sits on top of your flue. It has one simple job with several big payoffs: it keeps rain out of the chimney, keeps birds, squirrels and raccoons from getting in, stops leaves and fir needles from dropping down the flue, and its mesh screen catches sparks and embers before they land on your roof. If your chimney has no cap, or the cap it has is rusted through, loose or missing its screen, James Chimney Sweep can install or replace it as part of a visit anywhere in the Seattle, Tacoma and Puget Sound corridor.

This page is for homeowners who have noticed water in the firebox, heard scratching in the chimney, spotted an orange-brown cap from the street, or were told during an inspection that the chimney is open at the top. We cover what a cap does, how we confirm the right fit, the difference between galvanized, stainless and copper caps, and what actually drives the cost of the job.

Timing & Safety

When a chimney cap is necessary, and when it can wait

A cap is necessary when:

• The flue is open at the top. Rain entering an uncapped flue mixes with creosote to form an acidic sludge that eats at clay tiles, mortar and the damper, and it runs into the firebox.
• The existing cap is rusted through, missing its screen, or loose enough to blow off. A loose cap can land on the roof or in the yard.
• Animals have been inside. A bird or raccoon in the flue is a blockage risk, and a dead animal is an odor and health problem.
• You burn wood. The spark screen is what keeps embers off a cedar-shake or moss-covered roof.

A cap can wait, but should be on the list, when it is cosmetically rusty but still solid and screened, or when the chimney serves a gas appliance with its own listed termination that already includes a rain cover. In that case we will tell you so; we do not replace caps that are doing their job.

Safety considerations

• Please do not go on the roof to check or remove a cap yourself. Wet Seattle roofs and moss are slippery, and a technician has the equipment to work up there safely.
• A cap screen should never be removed to improve draft. If a fire drafts poorly, the cause is usually a blocked or dirty flue, a closed damper or a pressure problem in the house, not the screen.
• Caps on factory-built metal chimneys must be the type listed for that chimney system. A masonry cap forced onto a metal pipe can trap heat and restrict the flue.
• If an animal is currently in the flue, keep the damper closed and do not light a fire. We can remove debris and nesting material as part of the visit.
• NFPA 211 recommends an annual inspection of every chimney and vent. Cap condition is part of that inspection, which is how most rusted caps get caught before they fail.
• If you ever smell gas near a gas fireplace or appliance, leave the house and call your utility or 911 before calling anyone else.

Seattle & Puget Sound conditions

Seattle and the Puget Sound corridor are about as hard on a chimney cap as anywhere in the country. Months of steady rain mean an uncapped flue takes on a lot of water, and the same rain is why galvanized caps here turn orange far sooner than they would in a dry climate. The moisture that gets in does not dry out quickly, so creosote stays wet and acidic and flue tiles stay damp through the freeze-thaw nights of December and January. Add fir and cedar needles that collect on every roof, and the moss that grows on north-facing shakes and composition shingles, and a spark screen stops being optional for wood burners. A stainless or copper cap fitted once and checked at each annual inspection is the simplest protection a chimney in this climate can have.