Finishing; Non-Combustible Materials; Combustible Materials; Hearth Extension - Heat & Glo RH-36 Series Owner's Manual

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
Table 11.1
R = 1/k x inches of thickness
Table 11.2
Hearth Extension Insulation Alternatives-Total minimum R Value must equal 1.03
Material
Hearth & Home HX3, HX4 (Micore 300™)
USG Micore 160™
USG Durock™ Cement Board
Cement Mortor
Common Brick
Ceramic Tile
Armstrong™ Privacy Guard Plus
Marble
38
k per inch
thick
0.49
0.39
1.92
5.0
5.0
12.50
0.46
14.3-20.0
Heat & Glo • RH-36/RH-42 • 4044-153 • Rev AC • 1/11
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.
• You MUST use a hearth extension with this fireplace.
• Refer to Figure 11.1 for minimum dimensions.
• 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.
Minimum
r per inch thickness
thick required
2.06 1/2 in.
2.54 1/2 in.
0.52 2 in.
0.20 5-1/8 in.
0.20 5-1/8 in.
0.08 12-1/4 in.
2.18 1/2 in.
0.07-0.05 14-5/8 in. - 20-3/8 in.