Heat & Glo RUTHERFORD-50 Owner's Manual page 39

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 two HX4s (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
Protective
Metal Hearth
Strip
*
*
* 2 in. (51 mm)
Platform must be built
to raise the bottom of
the fireplace opening
to the level of the
desired hearth height.
Protective Metal
Floor
Hearth Strips
Noncombustible
Framing Material
Heat & Glo • RUTHERFORD-50 • 4059-333 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
39