CCS Hearth & Firebox Components Flashcards

What is the function of the smoke shelf in a fireplace firebox?

Answer: To catch falling debris and deflect cold downdrafts away from the fire

The smoke shelf sits behind the damper and catches falling soot, rain, and debris while deflecting cold downdrafts upward so they don't push smoke into the room.

What is the correct term for the angled rear wall of a firebox that helps direct smoke upward into the smoke chamber?

Answer: The fireback

The fireback is the angled or sloped rear wall of the firebox, designed to radiate heat into the room and direct combustion gases upward toward the smoke chamber.

Firebox walls must be built using which type of brick to withstand high combustion temperatures?

Answer: Firebrick (refractory brick)

Firebrick is made from refractory clay that withstands the extreme temperatures of combustion without cracking or spalling unlike standard brick.

What mortar must be used to repoint or repair firebox firebrick joints?

Answer: Refractory (high-temperature) mortar

Refractory mortar is rated to withstand firebox temperatures; standard mortars will crack and crumble under the same heat conditions.

What is the minimum recommended firebox depth from the front opening to the rear wall according to NFPA 211?

Answer: 12 inches

NFPA 211 requires a minimum firebox depth of 12 inches to allow safe combustion and proper upward draft toward the smoke chamber.

Which component sits directly above the firebox opening and forms the bottom boundary of the smoke chamber?

Answer: The throat damper

The throat damper is positioned at the top of the firebox opening, controlling the passage of air and smoke up into the smoke chamber.