SUPREME GALAXY, Owner'S Manual, Page: 13 / 25

GALAXY SUPREME FIREPLACES
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Use non-combustible materials only as shown in the shaded area. Decorative non-combustible materials such as tile, stone
and brick must be applied only on a non-combustible base such as cement board or Durock.
4.4 The Hearth Extension
The minimum dimensions of the hearth extension are specified in figure 17. The hearth
extension is to be covered with non-combustible materials only, such as steel, cement or
mortar,
stone, brick, ceramic tiles. Unidentified materials may be combustible: verify the
product specifications prior to installation.
The hearth extension must extend a minimum of 16 inches measured from the door of the
fireplace and extended all the way back to the fireplace.
WARNING: The hearth extension is to be installed only as illustrated in figure 17. The
hearth extension should extend a minimum of 16 inches from the fireplace door.
The non-combustible hearth extension must be constructed of materials having a minimum R-
Value of 0.39.
The R-Value is a measurement of the insulating properties of materials at a reference thickness.
When different materials are combined, the total R-Value is the sum of the individual R-Values.
Example:
Concrete 4” R-Value: 4 x .095 =.380
Ceramic ¼” R-Value: .020
Total R-Value: .380 + .020 = 0.400
The combination of 4” concrete with a ceramic tile is acceptable as a hearth extension since the
total R-Value is higher than the required .390.
Alternatively, the insulating properties can be defined as:
K-Factor: Thermal conductivity.
C-Factor: Thermal conductance.
In this case convert to R-Value as following.
Convert specification to R-Value :
i. R-Value given - no conversion needed.
ii. K-Factor is given with a required thickness (T) in inches: R = 1/k T
iii. C-Factor is given: R = 1/C
Figure 16 – Non-Combustible Face
Figure 17 – Hearth Extension