BW36 SERIES WOODBURNING FIREPLACE
No one builds a better fire
3. HEARTH EXTENSIONS.
A hearth extension must be installed with all fire- places. It is to protect the combustible floor in front of the fireplace from both radiant heat and sparks.
The construction of and materials used for a factory- built hearth extension are shown in Figure 5.
A hearth extension of this construction may be cov- ered with any
GAP (SEAL WITH | |||
DECORATIVE MATERIAL |
|
| |
|
| BLACK FIREPLACE BOTTOM |
|
1/2" | HX3 |
| |
| HEARTH SEALING STRIP | ||
| HEARTH EXTENSION |
|
Figure 5
Factory-Built Hearth Extension
Field constructed Hearth Extensions should be constructed in accordance with the minimum dimensions provided in Figure 6.
INSULATION MIN. R VALUE 1.16
EXAMPLES OF INSULATION
REQUIRED
THICKNESS K VALUE
USG MICORE CV230 | 1/2" | 0.43 |
(THERMAL CONDUCTIVITY) "K" = BTU in./hr. ft2 °F
TO SUBSTITUTE ALTERNATE INSULATION MATERIAL, YOU NEED TO KNOW THE "K" FACTOR FOR THAT MATERIAL. TO CALCULATE THE REQUIRED THICKNESS FOR THE ALTERNATE MATERIAL USE THE FOLLOWING FORMULA:
52"16"
K ALT. |
| |
| x .5 = THICKNESS OF ALTERNATE MAT. (INCHES) | |
.43 | ||
|
EXAMPLE:“K” OF BRICK = 5
5
x .5 = 5.81 IN. OF BRICK.
.43
Figure 6
Hearth Extension
WARNING!
HEARTH EXTENSIONS ARE TO BE INSTALLED ONLY AS ILLUSTRATED
TO PREVENT HIGH TEMPERATURES FROM OCCURRING ON CON-
CEALED COMBUSTIBLE MATERIALS. HEARTH SEALING STRIPS PRE-
VENT BURNING OR HOT PARTICLES FROM INADVERTENTLY FALLING
DIRECTLY ON COMBUSTIBLE SURFACES IN THE EVENT THE BUILDING
SHOULD SETTLE AND DISTURB THE ORIGINAL CONSTRUCTION.
10 | 30491D |