Chimney Sweep Glossary

This quick-glossary is your plain-English owner’s manual for Tacoma chimneys. Learn the 12 key terms every Puget Sound homeowner should know before lighting the first fire of fall, so you can spot trouble early and keep your hearth safe and warm all winter long.

Whether you just moved into a 1920s Craftsman in North Tacoma or bought a newer home in University Place, understanding your chimney’s parts helps you protect your family and your wallet. David S. Chimney Co. has been keeping Tacoma-area chimneys safe since 2008, and we’ve put together this no-jargon glossary so you can speak chimney like a pro. Need a closer look? Schedule a Level 2 inspection before the rainy season hits.

Creosote

Creosote is the black, tarry, sometimes shiny or crusty buildup that coats the inside of your chimney when you burn wood. It’s made of unburned wood particles, moisture, and chemicals from smoke. Creosote is highly flammable and the leading cause of chimney fires in Tacoma homes. A professional sweep removes it to keep your chimney safe and your insurance valid.

Flue

The flue is the vertical passageway inside your chimney that carries smoke and gases from your fireplace up and out of your home. In Tacoma, older homes often have a single-brick flue, while newer builds may use metal or clay tile liners. Keeping the flue clear and intact is essential for safe drafting and preventing carbon monoxide from entering your living space.

Flue liner

A flue liner is a protective layer that lines the inside of your chimney’s flue to shield the brick or masonry from heat and corrosive byproducts. Common types include clay tile, metal (stainless steel), and poured-in-place liners. If your Tacoma home was built before 1940, it may lack a liner—an urgent safety issue that a Level 2 inspection can confirm.

Damper

The damper is the movable metal plate located just above your fireplace that controls airflow. When open, it lets smoke exit up the chimney; when closed, it prevents heat loss and drafts. A stuck or missing damper can waste energy and increase heating costs in Tacoma’s damp winters. We check dampers during every sweep to ensure they operate smoothly.

Chimney crown

The chimney crown is the concrete or mortar cap that sits on top of your chimney, sealing the masonry from rain, snow, and debris. A cracked or crumbling crown lets water seep in, leading to spalling bricks and costly repairs. In Tacoma’s rainy climate, a well-maintained crown is your first line of defense against water damage.

Chimney cap

A chimney cap is a metal cover that fits over the top of your chimney to keep out rain, birds, squirrels, and falling leaves. It also prevents embers from escaping and igniting nearby roofs or trees. Without a cap, your flue can become a critter highway—especially common in Tacoma’s wooded neighborhoods like Proctor or North End.

Firebox

The firebox is the inner chamber of your fireplace where the fire actually burns. It’s lined with firebrick to withstand extreme heat. Over time, the mortar between bricks can deteriorate, creating gaps that allow heat to escape into your walls. A damaged firebox should be repaired before use to prevent structural damage or fire hazards in your Tacoma home.

Smoke chamber

The smoke chamber is the sloped area just above your firebox that funnels smoke into the flue. It’s designed to compress and speed up the smoke so it rises efficiently. A poorly maintained smoke chamber can collect creosote and debris, reducing draft and increasing fire risk—especially in older Tacoma homes with steeply sloped chambers.

Draft

Draft is the upward flow of air and gases from your fireplace through the chimney and out of your home. Good draft depends on temperature differences, chimney height, and a clear flue. If your Tacoma fireplace smokes into the room instead of up the chimney, weak draft is likely the culprit—often caused by a dirty flue, cold chimney, or wind patterns around your house.

Spalling

Spalling is the flaking or crumbling of brick and mortar caused by water absorption and freeze-thaw cycles. In Tacoma’s wet winters, spalling is a common sign your chimney needs tuckpointing or waterproofing. Left unchecked, spalling can weaken the entire structure and lead to costly masonry repairs or even chimney collapse.

Tuckpointing

Tuckpointing is the process of removing damaged mortar between bricks and replacing it with fresh, waterproof mortar. It restores the chimney’s structural integrity and prevents water intrusion. For Tacoma homeowners, tuckpointing is a smart investment to extend the life of an older chimney and avoid full rebuilds—especially in historic districts like Stadium or Old Town.

Chimney flashing

Chimney flashing is the thin metal strip that seals the joint where your chimney meets the roof, preventing water from leaking into your attic or walls. Over time, flashing can loosen or corrode, especially in Tacoma’s salty coastal air. Damaged flashing is a top cause of water damage and mold in local homes—inspect it annually.

Level 1 / Level 2 inspection

A Level 1 inspection is a basic visual check of accessible chimney parts—ideal for routine maintenance in Tacoma homes with no recent changes. A Level 2 inspection includes a video scan of the flue and is required after a chimney fire, fuel change, or when buying/selling a home. We recommend Level 2 before the rainy season to catch hidden damage from our damp climate.

CSIA certification

CSIA stands for the Chimney Safety Institute of America, the gold standard for chimney professionals. A CSIA-certified sweep has passed rigorous exams on chimney science, codes, and safety practices. David S. Chimney Co. only employs CSIA-certified technicians—because your family’s safety in Tacoma isn’t something we gamble with.

Chimney fire

A chimney fire occurs when creosote or soot inside the flue ignites, often with a loud crackling or rumbling sound and visible flames shooting from the chimney top. Even a small chimney fire can damage your liner and increase the risk of a house fire. In Tacoma, we see more chimney fires after cold snaps when homeowners stoke up their fireplaces without checking for creosote buildup.

Masonry chimney

A masonry chimney is built from brick, stone, or block and mortar—common in Tacoma’s older neighborhoods like Lincoln District or South Tacoma. While durable, masonry is porous and vulnerable to water damage, freeze-thaw cracking, and mortar deterioration. Regular sweeping and waterproofing are essential to preserve its lifespan in our rainy climate.

Prefabricated chimney

A prefabricated (or factory-built) chimney is a metal system assembled from pre-made parts, often used in newer Tacoma homes or as a replacement for older masonry chimneys. These systems are lighter and faster to install, but they require different maintenance than brick chimneys. Always use a CSIA-certified sweep familiar with your specific model to avoid voiding warranties.

Frequently Asked Questions