37
11
Finishing
A. Non-combustible Materials
• Materials which will not ignite and burn, composed of
any combination of the following:
- Steel
- Iron
- Brick
- Tile
- Concrete
- Slate
- Glass
- Plasters
• Materials reported as passing
ASTM E 136, Standard
Test Method for Behavior of Metals, in a Vertical Tube
Furnace at 750° C
B. Combustible Materials
• Materials made of or surfaced with any of the following
materials:
- Wood
- Compressed paper
- Plant fibers - Plastic
• Any material that can ignite and burn; flame proofed or
not, plastered or un-plastered
16 in.
406 mm
8 in.
203 mm
C. Hearth Extension
WARNING! Risk of fire!
High temperatures, sparks,
embers or other burning material falling from the fireplace
may ignite flooring or concealed combustible surfaces.
• Protective metal hearth strips MUST be installed.
• Hearth extensions MUST be installed exactly as
specified.
Table 11.1
Hearth Extension Insulation Alternatives-Total minimum R Value must equal 1.03
Material
k per inch
thick
r per inch
thick
Minimum
thickness
required
Hearth & Home HX3, HX4 (Micore 300™)
0.49
2.06
1/2 in.
USG Micore 160™
0.39
2.54
1/2 in.
USG Durock™ Cement Board
1.92
0.52
2 in.
Cement Mortor
5.0
0.20
5-1/8 in.
Common Brick
5.0
0.20
5-1/8 in.
Ceramic Tile
12.50
0.08
12-1/4 in.
Armstrong™ Privacy Guard Plus
0.46
2.18
1/2 in.
Marble
14.3-20.0
0.07-0.05
14-5/8 in. - 20-3/8 in.
R = 1/k x inches of thickness
• You MUST use a hearth extension with this fireplace.
• This fireplace has been tested and approved for use with
a hearth extension insulated to a minimum R value of
1.03.
• The hearth extension material MUST be covered with
tile, stone or other non-combustible material.
• Manufactured hearth materials will usually have a
published
R value
(resistance to heat) or
k value
(conductivity of heat). Refer to the formula in Table 11.1
to convert a k value to an R value,
• Refer to Table 11.2 for hearth extension insulation
alternatives.
Figure 11.1 Hearth Extension Dimensions
Heatilator • CL36D, CR36D • 12538 • Rev Z 7/12