WMC Series Woodburning Fireplace
COMMON MATERIALS AND FACTORS
MATERIAL | K* | R | MINIMUM |
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THICKNESS |
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EH2416 | 0.458 | 1.09 | 0.50 in.** |
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Common Brick | 5.0 | 0.10 | 5.46 in.** |
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R Value is for Z\x inch.
*Units of K = BTU/SQ FT/HR/˚F/IN ** Thickness of Listed Material
FP533ADD
Fig. 25 Hearth extension material factors.
Example of Determining Hearth Extension Equivalents
NEW | K of new material (per inch) | thickness |
required | = | X of listed |
thickness | K of listed material (per inch) | material |
To determine the thickness required for any new mate- rial:
Wall Covering
Noncombustible
Decorative
Facing
Seal all cracks between fireplace surround and wall materials with noncombustible material.
Noncombustible Decorative Covering 
Hearth Extension
Insulation
Side View
2x4" Header - Do not notch at standoffs.
Seal crack between fireplace and hearth extension with noncombustible material.
Safety Strips - Must be overlapped ¹⁄₂" minimum.
Example for Common Brick
T (new) = 5.0 / 0.458 x 0.50 in. = 5.46 in. (new re- quired thickness).
FP550
Fig. 26 Sealing gaps.
16 | 20000583 |
