Vermont Castings SB38 Nstallation, Operation And Maintenance Manual page 14

SB38 / SB44 Series Woodburning Fireplace
The ability of insulating material to retard the transfer of
heat may be expressed as either Thermal Conductance
(C), Thermal Conductivity (K), or Thermal Resistance (R).
The mathematical relationship of these values and the for-
mulas for converting one value to another is as follows:
C= K divided by the material thickness
(Example C = .43 divided by 1/ (.50)
C = .86)
K = C multiplies by the material thickness
(Example K = .86 multiplied by 1/ (.50)
K = .43)
R= The material thickness divided by K
(Example R = 1/ (.50) divided by .43
R = 1.16)
warNiNg: The hearth extension and the
metal safety strip should be installed only
in a horizontal relationship to the fireplace.
Figure 17
12"
Min.
Top of Raised
Hearth
With either type hearth extension minor shifting of the sup-
porting floor or expansion and contraction may eventually
cause a crack to develop between the hearth extension
and the face of the fireplace. To help prevent the crack from
developing, the hearth extension materials must be firmly
fastened in place. Wall ties should be screwed to the face
of the fireplace and imbedded in the mortar joints of brick,
stone, or other noncombustible materials. The metal safety
14
Figure 16
26 "
12"
Min.
Floor Line with Raised
Hearth
FP2240
floor protection 2
FP39
20"
FP2239
floor protection
20" Min.
Metal Safety
Hearth Extension
Strip
strip packed with the fireplace must be placed beneath the
fireplace and extended under the hearth extension or into a
mortar joint of the hearth extension as shown by Figures 13,
16 & 17. In the event a crack does eventually develop, the
metal safety strip will serve as a barrier to prevent sparks
or embers from falling from the fireplace onto combustible
flooring materials.
floor protectioN
Metal Safety
Strip
Combustible
Floor
SB38/38HB - 6" Min.
SB44/44HB - 68" Min.
FP40
87D0057