Hearth and Home Technologies CASTLEWOOD 42 - Manual (Page 22)

Outdoor Lifestyles by Hearth & Home Technologies Inc. • 4070-300 Rev D • 11/11 22
9
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
C. Hearth Extension
WARNING! Risk of fire! High temperatures, sparks, em-
bers or other burning material falling from the fireplace may
ignite flooring or concealed combustible surfaces.
• Metal hearth strips MUST be installed (Section 7.C.).
• Hearth extensions MUST be installed exactly as
specified.
Table 12.1
R = 1/k x inches of thickness
Table 12.2
Hearth Extension Insulation Alternatives-Total minimum R Value must equal 2.06
Material
k per inch
thick
R per inch
thick Minimum thickness required
Hearth & Home HX3, HX4 0.49 2.06 1 in. (25.4 mm)
USG Micore 300™ 0.49 2.54 1 in.(25.4 mm)
USG Durock™ Cement Board 1.92 0.52 4 in. (101.6 mm)
Cement Mortar 5.0 0.20 10 in. (254 mm)
Common Brick 5.0 0.20 10 in. (254 mm)
Ceramic Tile 12.50 0.08 25-3/4 in. (654 mm)
Armstrong™ Privacy Guard Plus 0.46 2.18 1 in. (25.4 mm)
Marble 14.3 to 20.0 0.07 to 0.05 29-1/2 to 41 in. (749.3 to 1041.4 mm)
• 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 2.32.
• 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 12.1
to convert a k value to an R value,
• Refer to Table 12.2 for hearth extension insulation
alternatives.
66 in.
(1676 mm)
42 in.
(1067 mm)
12 in.
(305 mm)
12 in.
(305 mm)
Raised Platform
20 in. (508 mm) Minimum
Flush Hearth
30 in. (762 mm) Minimum
Surfaces must be covered with non combustible material