Do you Know the Anatomy of Your Fireplace?

Fireplaces are widely appreciated because they provide the ideal setting for making memories with family and friends, in addition to providing warmth on cold winter days. Few people think in terms of the massive structure itself, which can weigh up to 7 tons. Maintenance is an important part of enjoying a fireplace, one generation after another. If you become familiar with the anatomy of the fireplace and the potential dangers associated with fires, the importance of regular upkeep makes more sense.

The foundation of a masonry fireplace is a crucial consideration. If the footing shifts and causes a crack, combustibles can become exposed to the fire; and the house could quickly burn down. Aside from the all-important foundation, which is usually made of heavy duty brick or cinderblock, here are the other components in the anatomy of a fireplace:

The Outer Hearth is the floor at the opening of the inner hearth, and it’s constructed with material that is heat resistant. This component of the fireplace provides needed protection from potential fire damage, such as when logs roll out of the fireplace.

The Inner Hearth, which is also called the Firebox, is where fires are built and the interior of the chimney is most readily accessible. Combustion occurs in the inner hearth. Fuel, a heat source, and oxygen are the three elements necessary for a fire to get started. The firebox is also a place where you may be able to notice shifting of the fireplace foundation. Check where the firebrick meets the facing material. It is recommended that rain water on the outside of the home be directed away from the fireplace, to help prevent circumstances that result in an unsettled foundation.

The Fireplace Face, which is usually made with brick, is the area just above and in front of the firebox, and it is beneath the mantel. The fireplace face must be capable of withstanding extreme temperatures from the fires; and it must be sturdy, being an important structural component of a fireplace.

The Mantel has traditionally been a prized focal point in a room, and originally it served the function of catching smoke. The function is no longer required, and modern fireplace design often eliminates the mantel altogether.

The Lintel is an important part of the fireplace; it helps to uphold the structural burden caused by the opening of the inner hearth. Other features with lintels are archways, door openings, and windows.

The Throat is directly above the firebox and is the beginning of the venting system. During construction of a fireplace, the fireplace throat is usually where a damper is installed. The throat is sometimes identified as the cause of a smoky fireplace, though the real problem is usually that it was built incorrectly or needs maintenance or repair.

The Damper, which is installed in the chimney flue and above the throat, is a metal door that must be opened when the fireplace is in use, to allow combustion gases to move outside through the chimney. It’s also important to close the damper when the fireplace is not in use, to prevent inside air from being pulled outside and vice versa. The damper must be installed at least 8 inches above the inner hearth, which is a change, since the minimum was previously 6 inches above the firebox.

The Firebrick, which is the back wall of the firebox, must be capable of withstanding very high temperatures. Firebricks are typically made with fire clay.

The Ash Dump Door makes it easy to remove ash from the firebox and is located in the middle of the inner hearth. The ashes fall in the Ash Dump. It’s important to remove ash routinely so that fresh fires can get an adequate amount of oxygen.

The Ash Pit is where dumped ash is collected and is located underneath the ash dump. To avoid dangerous buildup of flammable byproducts, the pit should be emptied often.

The Footing is below the ash pit, often in a basement; it is a horizontal surface.

The Clean-Out Door is used to clean the ash dump and is often located in the basement.

Does it come as a surprise that there are so many components of the fireplace? And that doesn’t even include all the parts of the chimney, which must also be maintained properly to avoid chimney fires and house fires. Contact our chimney technicians to schedule a fireplace and chimney cleaning and inspection.