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COLD CLIMATE INSULATION
If you live in a cold climate, it is especially
important to seal all cracks around the fireplace
opening with noncombustible material and
wherever cold air could enter the room. Sur-
rounding materials must be caulked where it
meets the black metal facing of the fireplace to
avoid cold air intrusion. Use noncombustible
caulking material only on fireplace facing to
seal. Also, the outside air inlet duct should be
wrapped with noncombustible insulation to
minimize the formation of condensation. Do
not place insulation materials against chimney
sections.
Note: A 2" (51 mm) air space must be preserved
for all combustible materials extending for any
continuous length adjacent to the chimney.
It is especially important to insulate between
the studs of an outside chase cavity and under
the floor if the floor is above ground level. Do
not place insulation directly against the fire-
place or chimney system
FIREPLACE FINISHES
Mantels and Trim
In Canada, the minimum height for a combus-
tible mantel is 24" (610 mm) above the fireplace
opening. Figure 53 shows typical Canadian
installation. In installations other than Canada,
combustible mantels and trim may be installed
12" (305 mm) above the fireplace opening as
per NFPA 211; Section 7-3.3.3. and Figure 54 .
If a mantel is of a noncombustible material, it is
exempt from these requirements as long as it
does not interfere with the installation or opera-
tion of glass doors.
Combustible
Mantel
8" Max.
(203mm)
24" Min.
(610mm)
Facing
Flush
Fireplace
Opening
Canadian Installation
Figure 53
16
Combustible
Mantel
and Trim
Figure 54
Hearth Extensions and Wall Shields
A hearth extension must be installed with all
fireplaces. Its purpose is twofold. It protects a
combustible floor in front of the fireplace from
both radiant heat and sparks and it distin-
guishes the prescribed hearth extension area
from other nonprotected surfaces. The hearth
extension must extend beyond the front at
least 20" (508 mm) and both sides at least 12"
(305 mm). Use the hearth extension constructed
of a durable noncombustible material having an
equal or greater insulating value of:
or a thermal resistance that equals or exceeds
r = 1.19 HR F FT
(10 mm) thick noncombustible material is all
that is required over a noncombustible or slab
floor.
Note: Any noncombustible material whose 1"
(25 mm) k value is less than .84 or whose r
value is more than 1.19 is acceptable.
Finished
Wall
If the fireplace is installed on a combustible
floor, use the metal safety strips (provided) on
the floor extending half under the fireplace and
Noncombustible
half under the hearth extension.
Wall Covering
Spacer
Secure the hearth extension to the floor to
prevent possible shifting.
If a continuous perpendicular side wall is closer
than 18" (457 mm) to the fireplace opening, a
wall shield is required. Use a 40" x 40" x
(1016 mm x 1016 mm x 13 mm) wall shield
constructed of millboard or a durable noncom-
bustible material with equal or greater insulat-
ing value than k = .84 BTU IN/FT
no case shall a continuous perpendicular side
wall be closer to the fireplace opening than 12"
(305 mm).
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
12"
Finished
(305mm)
Wall
Max.
1
" (38mm)
Noncombustible
Wall Covering
12"
Spacer
(305mm)
Min.
6
"
(167mm)
Fireplace
Opening
Typical Installation
2
k = .84BTU IN/FT
HR F
2
/BTU IN. A minimum
2
HR F. In
If fireplace is installed diagonally across a 90
corner; no wall shields are required.
Hearth Extension Dimensions
A
20" (508 mm)
B
36" (914 mm)
C
12" (305 mm)
D
60" (1524 mm)
40"
(1016mm)
40"
(1016mm)
C
B
Figure 55
"
C
B
D
Figure 56
Methods of Determining Hearth Extension
and Wall Shield Equivalents
To determine the thickness required for any
desired material when either the k or r values
are known:
T
= Thickness of desired material in inches
M
k
= k value of desired material
M
"
r
= r value of desired material
M
T
= Minimum listed thickness
Example: Micore CV230 is to be used with the
TM fireplace. How thick must this material be?
Wall Shield
Required if
less than
18" (457mm)
C
A
C
A
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