11
January 10, 2020
7045-910I
4100 Insert ACC
C. Alternate Floor Protection Calculation
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.
Thermal Protection
USA &
CANADA
Floor height 0” to 1-3/4” (0 to 44mm)
below insert base.
R=2.38
Floor height greater than 1-3/4” (44mm)
below insert base.
Only ember
protection
required.
0” - 1-3/4”
Thermal protection
required (1/2 inch of
R=2.38)
1-3/4” or more, Ember protection
only