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Installation and Operation Manual - Inspire 2000 Insert
9.2.2 Installation Raised of More Than 5"
If the extension of the masonry hearth is raised at least 5" (127 mm) from the floor protection, a non-
combustible material, without an R-value, must extend at least 16" (406 mm in USA) or 18" (457 mm
in Canada) in front of the unit.
HEARTH SLAB:
NON-COMBUSTIBLE MATERIAL
B
C
D
E
F
A
FLOOR PROTECTOR:
NON-COMBUSTIBLE MATERIAL
Figure 25: More than 5" raised base installation
9.2.3 R Value
There are two ways to calculate the R-value of the floor protection. First, by adding the R-values of
materials used, or by the conversion if the K factor and thickness of the floor protection are given.
To calculate the total R value from R values of the materials used, simply add the R-values of materials.
If the result is equal to or greater than the R-value requirements, the combination is acceptable.
R-values of some selected materials are shown below :
Table 4 : Thermal Characteristics of Common Floor Protection Materials*
MATERIAL
CONDUCTIVITY (K)
PER INCH
RESISTANCE (R) PER INCH
THICKNESS
Micore® 160
0.39
2.54
Micore® 300
0.49
2.06
Durock®
1.92
0.52
Hardibacker®
1.95
0.51
Hardibacker® 500
2.3
0.44
Wonderboard®
3.23
0.31
Cement mortar
5.00
0.2
Common brick
5.00
0.2
Face brick
9.00
0.11
Marble
14.3 – 20.00
0.07 – 0.05
Ceramic tile
12.5
0.008
*Information as reported by manufacturers and other resources
** Horizontal still air can’t be «stack» to accumulate R-values; each layer must be separated with another non-combustible material.
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