Lennox Hearth CAMBRIA 850 - Manual (Page 10)

Figure 14 - Hearth Extension and Clearances
Fireplace
Figure 13 - Hearth Extension Requirements
Framing, Facing And Mantel
The construction of the framing, facing, and
mantel must be in accordance with the stan-
dards and the following illustrations (Figures
15 through 20):
A. Frame the fireplace using 2” x 3” or heavier
lumber.
B. WARNING: Combustible materials can-
not be used in the space directly above
the fireplace, except for the studs above
the facade that support the facing and
mantel. This area must remain empty
for a height of 7 feet 6 inches (2286
mm) measured from the base of the
appliance.
C. Frame the fireplace with vertical studs at the
sides of the fireplace running from floor to
ceiling (see Figure 15). If combustible facing
is to be used, position the studs back, from
the front edge of the fireplace the thickness
of the facing material so that the facing can
be installed flush with the fireplace facing.
Frame headers between the vertical studs
only as follows:
• Place 2” x 3” or 2” x 4” headers, only
along the upper part of the front, side
and back faces. Do not put wood or any
combustible material within the area
above the fireplace except on the front
facing.
• Place headers only as required to support
the facing and mantel.
D. WARNING: The fireplace must not be
in contact with any insulation or loose
filling material. Cover the insulation
with drywall panels or any other rigid
material around the fireplace.
Hearth Extension Requirements - The Cam-
bria™ fireplace may be installed directly on a
combustible floor; however, the combustible
floor in front of the fireplace must be covered
with a 1/2 inch (13 mm) of non-combustible
support material (cement board, cement block
or other) before applying the finish material
(tile, marble, stone, etc.) (see Figures 13 and
14).
WARNING: It is important not to cover the
air ventilation opening below the facade
trim. (free space - Figure 13).
COLD CLIMATE INSTALLATIONS
Climates where temperatures will fall below
32° F (0° C).
The heating performance of the appliance will
vary depending upon the level of insulation, house
design, how the appliance is operated, etc.
If this fireplace is being installed in a cold
climate, it is especially important to seal all
cracks around the fireplace and wherever cold
air could enter the room with noncombustible
material. Also, the outside air inlet duct should
be wrapped with noncombustible insulation to
minimize the formation of condensation. Do
not place insulation materials directly against
the chimney sections. We recommend that you
use the insulated wall radiation shield since it
will maintain the home’s thermal barrier. AC
chimney is NOT recommended in very cold
climates (in areas with temperatures below
0°F (-18°C) .
Free Space u
Tile or Marble
2 x 4 Framing
Minimum 1/2”
Cement Board
59” Min.
18”
4”
33-3/4”
Non-Combustible
Material
45°
24”
Combustible material allowed in
the airspace above this area.
Cement
Board
Tile or
Marble
Elevated fireplace installations require a special
“Z” Metal Safety Strips (field provided), in place
of the safety metal strip shown above. The safety
strip should extend the full width of the fireplace.
When more than one safety strip is used they
must overlap by a minimum of 1”.
Platform
2”
Fireplace
Elevated Fireplaces
12”
MAX
Hearth extension of an elevated fireplace must respect the same minimal
dimensions than a fireplace installed directly on the floor.
10
WARNINGS :
THE HEARTH EXTENSION IS TO BE IN-
STALLED ONLY AS ILLUSTRATED.
u
DO NOT PACK REqUIRED AIR
SPACES WITH INSULATION OR
OTHER MATERIALS.
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THE CRACK BETWEEN THE FIRE-
PLACE AND THE HEARTH EXTENSION
MUST BE SEALED WITH A NON-
COMBUSTIBLE MATERIAL SUCH
AS A NON-COMBUSTIBLE SEALING
STRIP OR SAND CEMENT GROUT IN
THE AREA SPECIFIED ABOVE.
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Fireplace
Hearth
Extension
Mantel