Fireplace Installed Flush On The Floor And Hearth Extension Raised To Bottom Of Firebox Opening - Majestic SA42R Installation Manual

1. Fireplace Installed Flush on the Floor and
Hearth Extension Raised to Bottom of Firebox
Opening
Non-combustible flooring a minimum of 16 in. (406 mm)
in front of and 8 in. (203 mm) to each side of fireplace
opening of the SA36R. 20 in. (508 mm) in front and 12
in. (305 mm) to each side of the SA42R is required.
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 7.4 and 7.5.
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.
Note: Maximum height from floor under fireplace
to top of finished hearth extension is 8-1/16 in.
(205 mm).
Bottom of fireplace opening
Continuous,
non-combustible sealant
or grout
Tile, stone or other
non-combustible material
1/2 in. Micore
or equivalent
insulation
Floor constructed of wood or
other combustible material
Note: For installations
with vinyl flooring, special
clearance recommenda-
tions apply.
►
Figure 7.4 Hearth Extension Construction
►
Vinyl Flooring
Vinyl Flooring is sensitive to heat. A 48 inch minimum
depth hearth extension is recommended when using
vinyl flooring up to the wall. See Figure 7.4.
Notice: Clearances that do not meet the minimum
guidelines could result in damage or buckling to the
vinyl flooring and is done at the installer's risk.
Hearth and Home Technologies does not recommend
adhesive based vinyl flooring due to thermal expan-
sion. Floating-style flooring can be used, but will reach
temperatures up to 110°F in a room with ambient tem-
peratures of 70°F. Consult flooring specifications to
ensure compatibility.
Majestic Sovereign Series • SA36R/SA42R • Installers Manual • 4010-259 • Rev K • 1/22
Protective
Metal Hearth
Strip
2 in. (51 mm)
required
Note: The bottom of the fireplace
opening is 8-1/16 in. (205 mm)
above the bottom of the
fireplace. Finished hearth must
NOT extend above this level.
Noncombustible
SA36R 16 in. Min
Finishing Material
SA42R 20 in. Min
Hearth Extension
Noncombustible
Framing Material
1/2 in. Micore
or equivalent
insulation
Figure 7.5 Raised Platform Hearth Extension Detail
Noncombustible
Framing Material
Figure 7.6 Raised Platform Hearth Extension-Framing
Non-combustible
Finishing Materials
Figure 7.7 Raised Platform Hearth Extension-Finishing
Floor
Protective Metal
Hearth Strips
HX4 or
equivalent
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