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Heatilator • MEL36, MEL42 Installation Manual • 4044-212 • Rev D • 01/06/15
Noncombustible
Framing Material
HX4 or
equivalent
Figure 6.6 Raised Platform Hearth Extension-Framing
Non-combustible
Finishing Materials
Figure 6.7 Raised Platform Hearth Extension-Finishing
Floor
Non-combustible
Framing Material
Non-combustible
Finishing Material
Protective Metal
Hearth Strips
1/2 in. Micore
or equivalent
insulation
Note: The bottom of the fireplace
opening is 7.5 in. (191 mm)
above the bottom of the
fireplace. Finished hearth must
NOT extend above this level.
Non-combustible
material must be used
under the fireplace if
top of hearth is less
than 4 in. (103 mm)
below the fireplace
opening.
Figure 6.5 Raised Hearth Extension Detail
1. Hearth Extension 4” or more Below Fireplace
Opening
2 in. (51 mm) of the Protective
Metal Hearth Strip is required
under the front of the fireplace
Tile, stone or other
non-combustible material
Floor constructed of wood or
other combustible material
Fireplace
Opening
4 in.
(102 mm) min.
Continuous,
non-combustible sealant
1/2 in. Micore Hearth
Extension (or
equivalent insulation)
Figure 6.4 Hearth Extension Construction
WARNING! Risk of Fire. A raised hearth extension
built flush with the fireplace opening or less than 4 in.
(102 mm) below the fireplace opening requires the fire
-
place be installed on a non-combustible surface.
2. Hearth Extension Less Than 4” Below Fire-
place Opening
The hearth framing must be constructed of non-com-
bustible materials (such as metal framing or equivalent
material) and placed on HX3(s), HX4(s), or equivalent
material. See Figures 6.4 and 6.5.
When creating the platform, allow for the thickness
of the non-combustible finishing materials
.
Seal gaps between the hearth extension and the front
of the fireplace with a bead of non-combustible sealant
or grout.
or platform
C. Non-Combustible Sealant Material
After completing the framing and applying the facing
materials over the framing, a bead of noncombustible
sealant must be used to close off any gaps at the top
and sides between the fireplace and hearth.
Non-combustible Sealant
Figure 6.9 Place Non-combustible Sealant
