Hearth and Home Technologies BIR50-B - Manual (Page 40)

40
IMPORTANT! Hearth extension design must be determined
before installation of fireplace.
Floor
Non-combustible
Framing Material
Non-combustible
Finishing Material
Protective Metal
Hearth Strips
1 in. Micore or
equivalent insulation
& 1/2 in. Durock
Note: The bottom of the
fireplace opening is 3-3/4 in.
(95.3mm) above the bottom
of the fireplace. Finished
hearth extension must NOT
extend above this level.
Platform must be built
to raise the bottom of
the fireplace opening
to the level of the
desired hearth height.
20 in. Min.
Hearth Extension
Figure 12.3 Raised Platform Hearth Extension Detail
Raised Hearth Extension Framing
The hearth framing must be constructed of non-combus-
tible materials (Figure 12.2) and placed on 1/2 in. Durock
and 1 in. Micore (or equivalent material) (Figure 12.4).
When creating the platform, allow for the thickness of the
non-combustible finishing materials (Figure 12.5).
* 2 in. (51 mm)
Continuous,
non-combustible sealant
Tile, stone or other
non-combustible material
Floor constructed of wood or
other combustible material
1 in. Micore or
equivalent
insulation
(see Table)
Fireplace
Protective
Metal Hearth
Strip
1/2 in. Durock
*
*
Note: The bottom of the fireplace opening
is 3-3/4 in. (95.3mm) above the bottom of
the fireplace. Finished hearth extension
must NOT extend above this level.
Figure 12.2 Standard Hearth Extension Construction
Flush Hearth Extension Framing
• If the hearth extension and fireplace are recessed into
a combustible floor, the hearth extension must extend a
minimum of 30 inches in front of the unit.
• The fireplace should not be recessed more than 3 3/4 in.
(95.3 mm) below the surface of the finished floor.
• Refer to Figure 12.4.
Figure 12.4 Flush Hearth Extension Side View
Non-combustible Finishing Material Protective Metal
Hearth Strip
30 in. Min.
Hearth Extension
1 in. (25.4 mm)
Micore and
1/2 in. (13 mm)
Durock
Finished
Floor
Bottom of
Fireplace Opening
Note: The bottom of the fireplace opening
is 3-3/4 in. (95.3mm) above the bottom of
the fireplace. Finished hearth must NOT
extend above this level.
Heatilator • Birmingham BIR50-B • 4059-682D • 9/12