MHSC SB38 - Floor Protection

SB38 / SB44 Series Woodburning Fireplace
87D0057 13
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If this fireplace is installed on a combustible floor, the floor area 0 inches in front of, and 1 inches
either side of the fireplace opening must be protected by an insulating noncombustible hearth exten-
sion. This hearth extension may be either minimum 6-inch thick stone or brick as shown by Figure
13, an H066 hearth extension kit or a locally constructed equivalent to the H066.
The H066 hearth extension kit consists of sufficient insulation board to cover the floor area with
1/” inch layer of insulation. A 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 H066 hearth extension has a thermal conductivity (K factor) of 0.43. If
you do construct a hearth extension equivalent to the H066, 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/” covering provided by the H066.
Figure 15
Figure 13
12”
Min.
6” Min.
20” Min.
12”
Min.
FP2238
SB5400 dec hearth
Hearth
Safety Strip is Re-
quired When Unit
is Placed on a
Combustible Floor
or Platform
Brick or Stone Hearth Extension
- SB38/38HB 6” Long Min.
- SB44/44HB 68” Long Min.
Alternate brick or stone hearth
extensions for use with the SB38/
SB44 Series fireplace when
placed over a combustible floor
without insulation board protec-
tion.
FP38
12” 12”
20”
FP2239
SB5400
hearth protection
Screened Opening
FP39
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
Minimum Hearth Extension Dimensions
 A hearth extension placed on a
combustible floor must be constructed
with rigid insulation which has a mini-
mum “R” value of 1.16 or a “K” value of
0.43. The insulation must be covered
with a noncombustible covering such as
a tile, stone, marble, or a piece of 0.018
minimum sheet metal which is needed
to protect the insulation. Follow instruc-
tions provided with the for all other
specifications and directions for proper
installation of the fireplace and hearth
extension.
FP1168
finishing front
12/20/01 djt
 Do not
place finishing materials
beyond these edges or
cover air inlets
Screen
Rail
Hearth
FP1168
Figure 14
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

SB38/38HB - 6” Min.
SB44/44HB - 68” Min.