
CWC Series Woodburning Fireplace
COMMON MATERIALS AND FACTORS
| MATERIAL | K* | R | MINIMUM | |
| THICKNESS | ||||
| EH2416 | 0.458 | 1.09 | 0.50 in.** | |
| (MHSC) | ||||
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| Common Brick | 5.0 | 0.10 | 5.46 in.** | |
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R Value is for 1/2 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.
Seal crack between fireplace and hearth extension with noncombustible material.
Safety Strips -
Must be overlapped
Z\x" 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 | 87D1504 | 
