Your chimney is a focal point for home decor and necessary for home heating. Without the chimney, your fireplace would not have proper airflow to burn well, and would allow harmful smoke and toxic gases into your living space. In order to work properly, it must be properly constructed from top to bottom. Understanding the anatomy of your chimney will help you notice changes, suspect damage, and maintain it properly.

Foundation

Like the house itself, the chimney must be properly supported from beneath. Without a proper foundation, the masonry can shift, leading to cracks, leaning, and eventually structural damage.
Look for: signs of settling or movement, especially inside the firebox.

Ash Dump

The ash dump leads from the firebox through a type of trap door which makes it easy for homeowners to clean ashes from their fireplace by scooping it into the space below. The ash dump is a safe place for the ashes to cool and collect until it is too full to use.
Look for: ashes spilling out of the outlet or clogging the door.

Firebox and Hearth

The firebox is the space where the fire burns. It endures the most abuse–the highest temperatures and often the least attention. The hearth is the floor of the firebox which extends out toward the room. It is durable and usually decorative.
Look for: stains or cracks that indicate water damage.

Chimney Damper

Installed at the base of the chimney or a top mount damper installed at the top of the flue, the damper is essential for proper chimney function. It allows for adequate airflow to light and maintain a fire. A top mount damper and a throat damper can also prevent airflow during the off season.
Look for: drafts that affect your heating or cooling, a smoky fireplace, and animals in the flue.

Smoke Chamber and Shelf

The smoke chamber is the space above the fireplace where the heat and gases mix before continuing up the flue. The slanted wall directs the smoke upward, and the smoke shelf keeps the smoke and gas from falling back into the fireplace.
Look for: a smoky fireplace, rough walls, and dripping noises within the chimney that aren’t visible.

Flue Liner

The flue liner extends up the entire chimney and is made of clay tile, stainless steel, slip casting, and even HeatShield cerfractory sealant. It helps to properly size the flue for optimum airflow, protects the home from heat and gases inside the chimney, and protects the masonry from corrosive chemical byproducts inside the chimney.
Look for: pieces of clay tile inside the fireplace, chimney hot to the touch.

Chimney Crown, Cap, and Flashing

In order to maintain the integrity of the chimney, it needs protection against water penetration year-round. The crown is a mortar ceiling placed on top of the chimney, extending outward from the flue. The cap protects the flue opening, and the flashing protects the vulnerable intersection of the chimney and roof.
Look for: signs of water damage.

Every part of the chimney is essential and should be intacted for the chimney to work properly. Schedule an annual inspection to make certain the chimney is in good shape.

Call Billy Sweet Chimney Sweep at 617-469-4528 or request an appointment online today.