40
IMPORTANT! Hearth extension design must be
determined before installation of fi replace.
20 in. Min.
Hearth Extension
Floor
Noncombustible
Framing Material
Noncombustible
Finishing Material
Protective Metal
Hearth Strips
1/2 in. Micore
or equivalent
insulation
Figure 11.3 Raised Platform Hearth Extension Detail
Raised Hearth Extension FramingThe hearth framing must be constructed of non-combusti-
ble materials and placed on an HX4 or equivalent material
(Figures 11.2-11.4). When creating the platform, allow for
the thickness of the non-combustible fi nishing materials
(Figure 11.5).
1/2 in. Micore
or equivalent
Hearth must
extend at least
12 in. beyond
the fireplace
opening on both
sides.
20 in. Min.
Noncombustible
Framing Material
Figure 11.4 Raised Platform Hearth Extension-Framing Materials
Noncombustible
Finishing Materials
Figure 11.5 Raised Platform Hearth Extension-Finishing Materi-
als
2 in. (51 mm)
required
Continuous,
non-combustible sealant
Tile, stone or other
non-combustible material
Floor constructed of wood or
other combustible material
1/2 in. Micore
or equivalent
insulation
(see Table 11.2)
Fireplace
Protective
Metal Hearth
Strip
Figure 11.2 Hearth Extension Construction