8 in. (203mm) minimum
from each side of
fuel loading door
A
B
Figure 7.4 Minimum Hearth Extension Dimensions
Model #
A
B
NorthStar
in.
41
20
mm
1041
508
• Fireplace and Hearth Extension fl ush on the fl oor
Non-combustible fl ooring a minimum of 20 in. (508 mm)
in front of and 8 in. (203 mm) to either side of the fuel
opening is required as shown in Figure 7.4.
The construction of, and materials used for a hearth
extension are shown in Figure 7.5. A hearth extension
of this construction may be covered with any non-
combustible decorative material and may have a
minimum thickness as per Figure 7.5. Seal gaps between
the hearth extension and the front of the fi replace with a
bead of non-combustible sealant or grout.
Fascia
Outer Can
Flange
Protective metal
hearth strip
Tile,marble or other
non-combustible finish material
Minimum 4 in. (102 mm) Cement Board
or equivalent, (or two pieces HX4)
Minimum 20 in. (508mm) in front and
8 in. (203mm) on sides to fuel loading doors
Combustible Floor
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . .
Non-combustible
material supplied
with unit.
. . . . . . . . . . .
Non-combustible sealant or grout
Tile,marble or other
non-combustible
finish material
Figure 7.5 Fireplace and Hearth Extension Flush on the Floor.
• Raised Hearth Extension Framing
The hearth framing must be constructed of non-
combustible materials (such as metal framing or
equivalent material) and topped with two HX4s, or
equivalent material (Table 7.2).
When creating the platform, allow for the thickness of
the non-combustible fi nishing materials
(Figure 7.6).
Outer Can
Flange
Non-combustible
material supplied
with unit
Fascia
Protective metal
hearth strip
Minimum 4 in. (102 mm) Cement Board
or equivalent, (or two pieces HX4)
Minimum 20 in. (508 mm) in front and
8 in. (203 mm) on sides to fuel loading doors
Combustible Floor
Non-combustible sealant or grout
Tile,marble or
other
non-combustible
finish material
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . .
. . . . . . . . . . .
Non-combustible
framing materials
Figure 7.6 Raised Hearth Extension to Bottom of Fascia
• Fireplace installed fl ush on the fl oor and hearth extension
raised to bottom of fascia:
Non-combustible fl ooring a minimum of 20 in. (508 mm)
in front of and 8 in. (203 mm) to either side of the fuel
opening is required (see Figure 7.4).
WARNING! Risk of Fire!
Hearth extensions are to be installed only as illustrated
to prevent high tempertures from occurring on concealed
combustible materials.
36
Heat & Glo • NORTHSTAR • 480-2360 Installation Manual • Rev H • 8/20/14