smoke shelf

smoke shelf

[′smōk ‚shelf]
(engineering)
A horizontal surface directly behind the throat of a fireplace to prevent downdrafts.

smoke shelf

A concave shelf on the back wall of a smoke chamber, just above the throat, to redirect downdrafts into updrafts on the front wall of a smoke chamber.
References in periodicals archive ?
The relationship of the dimensions (opening height/width, firebox depth, size of smoke shelf and flue) is critical.
Use the noodle brush to remove all the soot from the smoke shelf. Then switch back to the long-handled brush to clean the sides of the firebox.
Scraped-off debris lands in the firebox and on the smoke shelf, where it's vacuumed up.