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
36
Outdoor Lifestyles by Hearth & Home Technologies Inc.• 4072-203 Rev A • 08/18
C. Hearth Extension
WARNING! Risk of fire!
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.
k per inch
r per inch
thick
thick
0.49
2.06
0.39
2.54
1.92
0.52
5.0
0.20
5.0
0.20
12.50
0.08
0.46
2.18
14.3-20.0
0.07-0.05
14-5/8 in. - 20-3/8 in.
High temperatures, sparks,
Minimum
thickness
required
1/2 in.
1/2 in.
2 in.
5-1/8 in.
5-1/8 in.
12-1/4 in.
1/2 in.