Heatilator BIR42 Owner's Manual page 42

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 fi nishing materials (Figure 12.5).
IMPORTANT! Hearth extension design must be determined
before installation of fi replace.
Continuous,
non-combustible sealant
Durock Tile, stone or other
non-combustible material
1 in. Micore or
equivalent insulation
(see Table)
Floor constructed of wood or
other combustible material
Figure 12.2 Hearth Extension Construction
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.
20 in. Min.
Hearth Extension
Noncombustible
Finishing Material
1 in. Micore or
equivalent insulation
& 1/2 in. Durock
Figure 12.3 Raised Platform Hearth Extension Detail
42
Protective
Metal Hearth
Strip
*
*
* 2 in. (51 mm)
Bottom of
fireplace opening
Platform must be built
to raise the bottom of
the fireplace opening
to the level of the
desired hearth height.
Protective Metal
Hearth Strips Floor
Noncombustible
Framing Material
Heatilator • Birmingham BIR42 • 4059-308 Rev F • 11/08
Noncombustible
Framing Material
Figure 12.4 Raised Platform Hearth Extension-Framing Materials
Noncombustible
Finishing Materials
Figure 12.5 Raised Platform Hearth Extension-Finishing Materials
1 in. Micore or
equivalent insulation
& 1/2 in. Durock