SR/SC Series "A" Woodburning Fireplace
COMMON MATERIALS AND FACTORS
MATERIAL | K* | R | MINIMUM | |
THICKNESS | ||||
|
|
|
EH2416 | 0.50 in.** |
(CFM Corporation) 0.458 1.09 | |
|
|
Common Brick 5.0 0.10 | 5.46 in.** |
R Value is for ¹⁄₂ inch.
*Units of K = BTU/SQ FT/HR/ßF/IN
**Thickness of Listed Material
FP533ADD
Fig. 24 Hearth extension material factors.
WARNING: HEARTH EXTENSION MUST BE INSTALLED IN ACCORDANCE WITH FIGURE 23 AND MUST NOT COVER THE BOTTOM FRONT OPENING OF THE CIRCULATING MODEL.
Alternate noncombustible materials may be used providing the (total) thermal resistance (Rt value) of the alternate material employed is greater than or equal to R = 1.09. Thermal resistance (R) or thermal conductivity (K), may be obtained from manufacturer of the material. Factors are related by the formula K = 1/R.
T = given thickness
R = thermal resistance for a given thickness (T) K = thermal conductivity
Noncombustible material with a lower R value may be used, provided thickness of material is sufficiently greater to maintain an equivalent (total) thermal resistance (Rt).
Example of Determining Hearth Extension Equivalents
To determine the thickness required for any new material:
NEW | K of new material (per inch) | thickness |
required = |
| x of listed |
| ||
thickness | K of listed material (per inch) | material |
Example for Common Brick
T (new) = 5.0/0.458 x 0/50 in. = 5.46 in. (new required thickness).
Side View
Wall Covering |
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
|
|
|
|
|
|
|
|
|
|
| ||||||||||||||
Noncombustible |
|
|
|
|
|
|
|
| 2 x 4 Header | |||||||||||||||
Decorative |
|
|
|
|
|
|
|
| ||||||||||||||||
|
|
|
|
|
|
|
| (Do not notch | ||||||||||||||||
Facing |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||||
|
|
|
|
|
|
|
|
|
|
|
|
| at standoffs) | |||||||||||
Seal all cracks |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
between fireplace |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
surround and wall |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
materials with |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
noncombustible |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
material |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Noncombustible |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
Decorative |
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||||||||||
Covering |
|
|
|
|
|
|
|
|
|
| ||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Seal crack between | ||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||
Hearth Extension |
|
|
|
|
|
|
|
|
| fireplace and hearth | ||||||||||||||
|
|
|
|
|
| extension with | ||||||||||||||||||
Insulation |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||||
|
|
|
|
|
|
|
| noncombustible | ||||||||||||||||
|
|
|
|
|
|
|
| |||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| material | ||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Safety Strips | ||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Must be overlapped 1/2" | ||||||
FP550 |
|
|
| minimum | ||||||||||||||||||||
|
|
|
|
|
|
|
|
|
| |||||||||||||||
Fig. 25 Sealing gaps.
7412948 | 17 |
