Document kDJ4Jj6OO2jnG6vaLBBrMKE3n
Heat Tra^fflissin Coefficients of Building Materials
141
r,,MBINED COEFFICIENTS,OF TRANSMISSION (10 OF PITCHED ROOFS" AND Tabus 17. {Iorizontal Ceilings--Based on Ceiling Area1
a Calculations based on 1 pitch roof' (n = .1.2) using the following formula: -
Ur X ` Uc9 U = ----------jj--
Ur 4- --^ n
U *= combined coefficient to be used with ceiling area. ur = coefficient of transmission of the roof. C/e* -- coefficient of transmission of the ceiling.
n = the ratio of the area of the roof to the area of the ceiling.
^ Use ceiling area (not roof area) with these coefficients.
.
Coefficients in Columns D, E and F may be used with sufficient accuracy for tile, slate and rigid as
bestos shingles on wood sheathing.
d Based on 1 x 4 in.-strips spaced 2 in. apart.
* Sheatiling assumed if in. thick.
/ Values of C/m to be
in this column may be selected from Table 11.