Specifications

12 63D4004
FLOOR PROTECTION
CALCULATING ACCEPTABLE ALTERNATE FLOOR MATERIALS
All fl oor protection must be non-combustible (i.e. metal, brick, stone, mineral fi ber, etc.). Any organic materials (i.e. plastics,
wood or paper products, etc.) are combustible and must not be used. The fl oor protection specifi ed includes some form of
thermal designation such as R-value (thermal resistance) or k-factor (thermal conductivity).
PROCEDURE:
1. Convert specifi cation to R-value:
R-value given. No conversion needed. k-factor is given with a required thickness (T) in inches. R = (1/Kx12) xT
k-factor is given with a required thickness (T) in inches: R = (1/k) x T r-factor is given with a required thickness (T) in inches. R = r x T
2. Determine the R-value of the proposed alternate fl oor protector.
a. Use the formula in step (1) to convert values not expressed as "R."
b. For multiple layers, add R-values of each layer to dtetermine overal R-value.
3. If the overall R-value of the system is greater than the R-value of the specifi ed fl oor protector, the alternate is
acceptable.
EXAMPLE: The specifi ed fl oor protector should be 3/4" thick material with a k-factor of 0.84. The proposed alternate is 4"
brick with and R-factor of 0.2 over 1/8" mineral board with a k-factor of 0.29.
Step A. Use formula above to convert specifi cation to R-value. R= (1/k) x T = (1/.84) x 0.75 = 0.893
Step B. Calculate R of proposed system.
4" brick of R = 0.2, therefore: Rbrick = 0.2 x 4 = 0.431
1/8" mineral board of k = 0.29, therefore: Rmineral board = x 0.125 = 0.431
Rtotal = Rbrick + Rmineral board = 0.8 + 0.431 = 1.231
Step C. Compare proposed system Rtotal of 1.231 to specifi ed R of 0.893. Since proposed system Rtotal is greater than
required, the system is acceptable.
(ft
2
)(hr)(ºF) Btu(in) Btu(ft) (ft
2
)(hr)(ºF)
Btu ft
2
(hr)(ºF) ft
2
(hr)(ºF) Btu(in)
R =
k =
= K x 12 K = r =
1
=
k