53D9025
11
FLOOR PROTECTION
If this fireplace is installed on a combustible floor, the floor area 20 inches in front of, and 12 inches either side of the
fireplace opening must be protected by an insulating noncombustible hearth extension. This hearth extension may
be either minimum 6-inch thick stone or brick as shown by Figure 9, an H2068 hearth extension kit or a locally con-
structed equivalent to the H2068.
The H2068 hearth extension kit consists of sufficient insulation board to cover the 20” x 68” floor area with ° inch layer
of insulation. A 20” x 68” piece of galvanized steel is included in the kit to cover the insulation before a finishing layer
of noncombustible material of stone, brick, tile, etc., is applied to finish the hearth extension.
The insulation used in the H2068 hearth extension has a thermal conductivity (K factor) of 0.43. If you do construct a
hearth extension equivalent to the H2068, be sure the insulation you use has enough compressive strength to support
the weight of the covering materials and persons standing on it, and insulating qualities equal to or better than the 1/2”
covering provided by the H2068.
Alternate brick or stone hearth
extension for use with the SB4800
fireplace when placed over a
combustible floor without insulation
board protection.
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Figure 9
12”
Min.
SB4800 Fireplace
Hearth
Brick or Stone Hearth
Extension
(62” Long Minimum)
6” Min. Brick or
Stone from Top
of Platform
Safety Strip is required when
unit is placed on combustible
floor or platform.
12”
Min.
20” Min.
62”
20”
12”
12”
FP1885
hearth extension
8/08
Figure 10
Fireplace and Hearth Extension
- Top View
MHSC H2068 Hearth Extension or
Equivalent
NOTE:
A hearth extension placed on a combus-
tible floor must be constructed with rigid insula-
tion which has minimum “R” value of 1.16 or a “K”
value of .86. The insulation must be covered with
a non-combustible covering such as tile stone,
marble or a piece of .018 minimum sheet meal
which is needed to protect the insulation. Follow
instructions provided with the fireplace for all oth-er
specifications and directions for proper instal-lation
of the fireplace and hearth extension.
