10
7044-225I
August
13,
2018
3100 Insert ACC
C. Calculating Alternate Floor Protection
Material
Thermal Resistance: R value
The R value is a measure of a material’s resistance to heat
transfer.
R value is convenient when more than one material is used
since you can add the R values together, whereas you can
not do this for k value.
The HIGHER the R factor means less heat is being
conducted through the non-combustible material to the
combustible material beneath it.
The R value of a material must be equal or larger then the
required R value to be acceptable.
Figure 10.2
ZERO
CLEARANCE
ONLY
Required
Thermal
Protection
Adj. Hearth
Support
R= 3.06
0 to 6-1/2 inch
(0 to 165mm)
ZERO
CLEARANCE
ONLY
Required
Thermal
Protection
R= 2.04
Adj. Hearth
Support
6-1/2 inch
(165mm
)
Figure 10.1
Zero Clearance Floor Thermal Protection
THERMAL
PROTECTION
USA
& CANADA
Floor height 0” to 6-1/2” (6mm to 165mm)
below insert base
R=3.06
Floor height greater than 6-1/2” (165mm)
below insert base
R= 2.04
