What a Chimney Camera Inspection Actually Finds

A chimney camera inspection finds the problems inside the flue that no flashlight, mirror or look from the roof can reach: cracked or shifted flue tiles, open mortar joints between tiles, glazed creosote, gaps and rust in metal liners, hidden blockages, and the fingerprints of a past chimney fire. The camera travels the full length of the flue, from the smoke chamber to the cap, and records every joint on the way.

That is the whole reason a camera is part of a Level 2 chimney inspection and not a Level 1. A Level 1 covers what is visible from the firebox, the roof and the exterior. Most of a chimney is none of those places. This article walks through what the camera actually shows us on Seattle-area chimneys, what each finding means for you, and which ones are safety problems versus water problems versus things to keep an eye on.

How a chimney camera inspection works

The camera is a small, lighted head on a long push rod or cable, feeding a screen and a recorder. We run it from the firebox up through the damper and smoke chamber into the flue, or from the top of the chimney down, depending on the chimney and the question we are trying to answer. The flue needs to be swept first; a camera cannot see through a coating of soot, and a heavy creosote layer hides exactly the cracks we are looking for. That is why the camera scan is usually paired with a chimney sweep.

As the camera moves, we pause at every tile joint, every offset, and anything that looks different from the section before it. Still images of each finding go into your written report, so you can see what we saw rather than take our word for it.

What the camera finds in clay tile liners

Most Seattle masonry chimneys built before the 1980s have a clay tile liner: a stack of fired clay sections, usually two feet long, mortared end to end. The median Seattle home was built in 1976 and the median Tacoma home in 1967, so a large share of the flues we scan are tile liners that have been through many decades of fires and wet seasons. The camera finds:

Cracked flue tiles

Vertical or spiral cracks in a tile. A single hairline crack may have come from a hot fire or from the chimney settling. A crack that runs through several tiles in a row, especially with creosote puffed up around it, is the classic sign of a past chimney fire. Cracks matter because they let heat and gases out of the flue and into the surrounding brick, and a chimney fire can push through a cracked tile to reach wood framing.

Missing or broken tile sections

A tile that has spalled inward, broken off, or is simply not there. Fragments often show up on the smoke shelf before the camera reaches the gap. A missing section means the flue is unlined at that point.

Open or washed-out mortar joints

The mortar between tiles erodes from heat, acid condensate and water. On camera, an open joint shows as a dark gap or a ledge where creosote collects. Open joints are the most common tile-liner finding we record in the Puget Sound, and water coming in from the top of the chimney makes them worse every wet season.

Shifted or offset tiles

Tiles that no longer line up, creating a step in the flue wall. Settlement, a poorly built original chimney or an earlier chimney fire can cause this. Offsets catch creosote and can restrict draft.

What the camera finds in metal liners and prefab pipe

Homes built after the mid-1980s across Renton, Redmond, Bothell, Gig Harbor mostly have factory-built fireplaces with metal pipe inside a framed chase, and many older masonry chimneys have been relined with stainless steel. In metal flues the camera finds:

• Separated or unlocked pipe sections, usually at a joint near an offset
• Rust, pitting or perforation, often from water coming in around a rusted chase cover
• Crushed or dented liner sections from installation or from something dropped down the flue
• Creosote build-up on a liner that was sized too large for the appliance and runs cool

Rust inside the pipe almost always points to a water problem outside it. On a framed chase the usual cause is a galvanized chase cover that has rusted through; chase cover replacement starts at $299 and usually fixes the source.

Creosote the camera sees and a flashlight cannot

Creosote comes in stages. The powdery and flaky kinds brush out in a normal sweep. Glazed creosote is the hard, shiny, tar-like layer that forms when smoke cools and condenses in the flue, and it is the kind that burns hottest in a chimney fire. A flashlight from the firebox shows you the first few feet. The camera shows whether there is glaze higher up, how thick it is, and whether it has already puffed and bubbled, which means it has been lit at least once. That finding changes the advice from "sweep it" to "this flue has had a fire; let's look at the tiles."

Blockages and debris

The camera also finds what is simply in the way: old nests on the smoke shelf, leaves and fir needles packed below a missing cap, fallen tile and mortar fragments, and sometimes an animal. A flue that is partly blocked will draft poorly and push smoke into the room. If the camera finds an active nest or an animal, we do not light a fire to drive it out, ever. Chimney swifts are protected under the federal Migratory Bird Treaty Act, and an active swift nest stays until the birds have left. Our animal and nest removal page covers how that is handled, and a proper cap keeps it from happening again.

Signs of a past chimney fire

Sellers and even long-time owners are often unaware a chimney fire has happened, because small ones burn out on their own. The camera finds the evidence: puffy, honeycombed creosote; tiles cracked in a pattern along the flue; discolored or warped metal liner; and mortar joints blown open. This is one of the main reasons NFPA 211 recommends a Level 2 inspection with camera when a home is sold. If you are in the middle of a purchase, our home buyer's guide explains how to fit the inspection into your contingency period.

What the camera does not find

The camera inspects the inside of the flue. It does not see the crown, the cap, the flashing or the outside of the brick; those get inspected from the roof and the ground as part of the same Level 2 visit. That exterior half matters in Seattle. Sea-Tac's normal annual rainfall is 40.34 inches with November the wettest month at 6.31 inches, and winter lows sit just above freezing, so wet brick at the top of a chimney goes through repeated freeze and thaw. The Brick Industry Association's technical notes tie that cycle to cracking and spalling in saturated masonry. Many of the open joints and rust the camera finds inside started with a cracked crown or failed flashing outside, which is why the report looks at both together. Crown repair and a crown rebuild starting at $299 are the most common exterior follow-ups.

Reading the report: safety, water, or watch

We sort camera findings into three groups so you know what to do with them:

• Safety: cracked or missing tiles, open joints, liner breaches, glazed creosote, fire evidence. Do not use the fireplace until addressed.
• Water: rust in a liner, staining, efflorescence, joints eroding from the top down. Fix the entry point before it reaches the safety list.
• Watch: a single hairline crack with no creosote, minor offsets, light creosote. Re-check at the next annual inspection.

Every finding comes with a camera still, a free quote for the repair, and our price match plus 10 to 25 percent off any written competitor quote. If another company has already told you the flue needs relining, a free 2nd-opinion camera scan is a cheap way to confirm it before you spend the money.

What to do next

• If your flue has never been scanned, or it has been years, ask for a Level 2 inspection with camera at your next sweep.
• If you are buying or selling, or had a chimney fire or storm damage, book the camera inspection now rather than at the end of the contingency period.
• Call 206-453-2045 or request a free quote online. Same-day service is often available in Seattle, Tacoma, Everett and across King, Pierce and Snohomish counties.
• If you're not happy with the work that follows, we're not done. That guarantee applies to every repair the camera finds.

Related

• Chimney Inspection Levels 1, 2 and 3 Explained
• Buying a Home in Seattle? Why a Level 2 Chimney Inspection Belongs on Your List
• Chimney Inspection service