Monessen Hearth BWBC500MHB - Manual (Page 11)

61D0087 11
16"min. - 400 unit
20" min. - 500 unit
8 " 8 "
Figure 9 - Installing Hearth Extension and Metal Safety Strip
Only install metal safety
strip horizontal to the
fireplace.
W
ARNING
Fireplace
Metal
Safety Strip
*HEARTH EXTENSION EQUIVALENTS
Hearth extensions are made of a 1 /
2
" thick piece of **MICORE CV230 fiberboard covered with a sheet of 26 gauge galvanized
steel. You may purchase these materials locally to fabricate hearth extensions. You can construct hearth extensions from any
noncombustible material that is 1 /
2
" thick with a “K” value (thermoconductivity) of 0.43 or lower.
For example, an insulating material 1 /
2
" thick with a “K” value of 0.35 would be acceptable. A hearth extension made from
materials 1 /
2
" thick with a “K” value of 0.43 or lower is equal to the H1652 or H2066 hearth extensions. See Figure 8, page
10.
**MICORE CV230 is manufactured by U.S. Gypsum Corporation.
The following relations could be useful:
C = K divided by the material thickness
(Example C = .43 divided by 1/2 (.50)
C = .86)
K = C multiplies by the material thickness
(Example K = .86 multiplied by 1/2 (.50)
K = .43)
R = The material thickness divided by K
(Example R = 1/2 (.50) divided by .43
R = 1.16)
C = Thermal Conductant
R = Thermal Resistance
FIREPLACE INSTALLATION