Chimney safety
Your chimney is the one appliance that lives outside, in nine months of Pacific Northwest rain. Here's what actually keeps it — and your family — safe, explained the way we'd explain it over your fence.
A fireplace seems like the simplest thing in the house — strike a match, get warm. But the chimney behind it? That's a working safety system with one job: carry flammable creosote and toxic combustion gases up and out, every single time you burn. When any link in that chain gives out — a cracked liner, a clogged flue, a missing cap — you're left with the two risks that matter: a chimney fire and carbon monoxide drifting back inside.
And around here, the clock runs a little faster. From the older waterfront cottages of Juanita and Kenmore to the newer builds around Totem Lake and the Woodinville valley, every chimney lives through the same long, damp winters: humid air off the lake working on metal and mortar, and freeze-thaw snaps cracking wet masonry from the inside out. The honest good news? Nearly every chimney hazard is predictable — and preventable — with a yearly check and a few sound repairs. Let us walk you through it.
Start here
The national fire-safety standard, NFPA 211, calls for every chimney, fireplace and vent to be inspected at least once a year — and there's a good reason. Almost everything that fails does it out of sight: inside the flue, up on the crown, under the flashing. A glance from the hearth tells you nothing. A proper chimney inspection runs a camera through the whole system and catches the small stuff while it's still small.
Think of it as the cheapest peace of mind you'll buy all year: before that first crackling October fire, you'll know the flue is clear and the structure is sound.
The #1 fire risk
Here's the plain version: every time wood smoke cools inside your flue, it leaves creosote behind — and creosote burns. It builds in three stages, and each one is harder to remove than the last. Let it reach the glazed Stage 3 and you're storing fuel in your chimney; if it ignites, a chimney fire can get hot enough to crack a liner in minutes.
Burning seasoned, dry wood slows the buildup — but nothing stops it entirely. That's what a routine chimney sweep is for, and when buildup has gone hard and glassy, creosote removal takes away the fuel a chimney fire needs.
The invisible risk
CO gives no warning — no color, no odor. If a flue is blocked or cracked, it can drift back into the house instead of out. A sound liner, a clear flue and CO alarms on every level are your three layers of protection.
Carbon monoxide, in detail
Everything that burns fuel in your home — a wood stove, a gas fireplace, a furnace or water heater venting through the chimney — makes carbon monoxide as a byproduct. When the flue is healthy, that gas rides straight up and out and you never think about it. But what happens when a bird builds a nest in the flue, or creosote chokes it down, or a crack lets gases seep into a wall cavity? CO can wander back into the rooms where you live and sleep. Since you can't see it or smell it, your defenses have to be layered: a clear, properly sized flue, an intact liner, and a working CO alarm on every floor and near the bedrooms. Our neighborly reminder: test those alarms when the clocks change, and never run a fuel-burning appliance if you suspect the flue is blocked.
Lake-country wear
Brick and mortar are porous — they drink. Around Lake Washington and the Sammamish valley, they get months to do it: rain soaks in through fall and winter, and when a cold snap arrives, that trapped water freezes, expands, and breaks the masonry apart from the inside. That's the freeze-thaw cycle, and the damp lake air piles on by keeping everything wet longer and corroding any metal it reaches.
Catch it early and it's a simple masonry repair — repointing a few joints, rebuilding a crown. Ignore it and the water keeps working its way toward the flue. A breathable waterproofing seal is the most cost-effective way we know to slow the whole process down.
The flue's last defense
Inside your chimney is a sleeve you'll never see — the liner — and it's doing the most important job in the whole system: keeping heat and gases where they belong. In the older homes around Houghton, Juanita and downtown Bothell, that liner is often original clay tile, and clay cracks — with age, with moisture, and especially after a chimney fire.
Let's be straightforward about this one: a cracked or missing liner isn't cosmetic, it's a safety problem. When an inspection turns up liner damage, chimney relining with a correctly sized stainless liner puts the barrier — and the draft — back where they should be.
Keep the weather out
If chimneys have one true enemy in the Pacific Northwest, it's water — and we get our share of it. An open or rusted-out flue lets rain fall straight onto the liner and damper for months on end; failed flashing sends it into the ceiling and walls instead. A stainless chimney cap earns its keep twice over: it doubles as a spark arrestor, and it keeps the birds and squirrels — who love a warm flue as much as you love your fireplace — from building a dangerous blockage.
Honest boundaries
A few good habits between visits go a long way. But the flue, the roof and anything connected to fuel? That's work for trained hands, and we say that as the people who'd rather keep you off a wet roof.
Before the first fire
Late summer or early fall beats the October rush — and leaves time for any repairs before you actually need the fireplace.
Clearing last season's buildup means the chimney starts winter fresh, with a strong draft and no stored fuel in the flue.
These three parts are what stand between nine months of rain and the inside of your chimney. Make sure all three are doing their job.
Fresh batteries, then test the smoke and carbon-monoxide alarms on each level and near the bedrooms.
Seasoned, dry hardwood only. Wet or green wood smolders, cools too fast, and paints your flue with creosote.
Keep reading
More straight talk from the crew — practical, no-pressure advice for keeping chimneys safe, efficient and watertight through our long lake-country winters.
Common questions
Peace of mind starts here
Grab a real opening on our calendar — booking is free, no card needed. Kirkland Chimney Pros photographs every visit, and you only ever pay for work you've approved in writing.
