_Width_ _Height_ _Depth_
2'-8" 2'-4" 17" to 21"
3'-0" 2'-4" to 6" 21"
4'-0" 2'-8" 21" to 25"
Arched openings may be higher than indicated in the above
dimensions, as their average height may be taken as the top line of
the opening.
[Sidenote: Construction]
The ideal form of a fireplace would be a cone with all sides
tapering to the apex for the escape of smoke. Therefore, to
approach this ideal in practice, the sides of the fireplace are
splayed and the back curved forward as shown in Figs. 36 and 37.
This forward curve of the back throws the smoke from the fire
forward to a throat 4 inches wide, extending the full width of the
opening at the front and top of the fireplace, and at the same
time forms a shelf above for the deflection of down drafts in the
chimney. The rear wall of the fireplace should never be straight,
having the throat at the rear, as down drafts would be sure to blow
smoke and dust into the room.
[Illustration: Fig. 37. Cross Section of Fireplace]
[Sidenote: The Damper]
Always place a damper in the throat for regulation of the draft.
The damper should completely fill the throat. There are many
dampers on the market that also serve the purpose of a lintel for
the brickwork, giving a smooth surface for the exit of the smoke.
These patent combinations of damper and throat give a good draft,
prevent smoke, and deserve a more general use.
[Illustration: Fig. 38. Hearth With Brick on Edge]
Especial care should be taken in laying up the brickwork above and
around the damper. The joints should be well filled, and nowhere
should there be less than an 8-inch thickness of brickwork unless
protected by the flue lining.
[Sidenote: The Flue]
Immediately above the damper, the brickwork should be corbeled
in both ways to the size of the flue lining, which should always
be started on a line with the middle of the fireplace and run
vertically for one length. It then may be jogged over to the
location desired on the floor above. It should be started as low as
possible as this is the hottest part of the chimney.
The back and sides of the fireplace, as well as the back portion
of the hearth are usually built of fire brick. Certain kinds of
face brick are suitable for this purpose and have been used by
architects with very artistic results.
[Sidenote: The Hearth]
The hearth may be either of face brick or tile. If of brick, they
should be preferably smooth so as to facilitate cleaning. They
may be laid either on edge or flat in a variety of patterns. Two
examples of brick hearths are shown in Figs. 38 and 39, one with
the brick set on edge and the other with the brick laid flat. Tiles
may be of any size and laid in various patterns, and if suitable,
may be used also in the back portion of small hearths. The mortar
joints of the hearth should be thin and preferably of a fire clay
mortar, though pure cement mortar will answer the purpose. Wherever
possible, an opening and ash chute in the back hearth, with a pit
and iron cleanout door in the basement, should be installed.
[Illustration: Fig. 39. Hearth With Brick Flat]
Always build the fireplace in the rough first, leaving the brick
facing and hearth to be finished after the plasterer has completed
his work. The accompanying designs, A, B, and C, suggest various
methods of treatment.
[Illustration: Fireplace Design A]
[Illustration: Fireplace Design B]
[Illustration: Fireplace Design C]