Hearthstone Quality Home Heating Products, Inc.
® Morgan Model 8470
6
Floor protector’s come with various types of
specifications. To convert a floor protector’s specification
to an R-value, do one of the following:
If the R-value is given, use that value—no
conversion is needed.
If a K-factor is given with a required thickness
(T) in inches, use this formula: R-value = 1/K x
T
If a C-factor is given, use the formula: R-value =
1/C
To determine the R-value of the proposed alternate floor
protector:
Use either the K-factor or the C-factor formula
explained above to convert specifications not
expressed as R-values.
For multiple layers of floor protectors, simply
add the R-values of each layer to determine the
overall R-value of the layers.
If the overall R-value of your setup is greater than the
R-value of the specified floor protector, then your setup is
acceptable.
Noncombustible Material
Thickness
R-value
Gypsum or plaster board
1
1
/
2
0.45
Wallboard, Wonderboard, or
Durock
1
1
/
2
0.20
Ceramic board (Fiberfrax or Micor)
1
1
/
2
1.10
Nominal solid clay brick
1
1
0.20
Ceramic wall or floor tile
1
1
/
4
0.01
Mineral wool insulation
2
1
3.12
Cement mortar
2
1
0.20
Horizontal still air
2
*
1
/
8
0.92
1
According to Intertek Testing Services, Inc.
2
According to ASHRAE Handbook of Fundamentals
1977
