Document Znj99zpYnXNnNgzbnv71pv97d

192 CHAPTER 9 1950 Guide Table 14. Coefficients of Transmission (U) of Flat Roofs Covered with Built-op Roofing. No Ceiling--Under Side of Roof Exposed (See Table 15 for Flat Roofs with Ceilings) These coefficients are expressed in Bln per (hour) (nuars foot) (Fahrenheit degree difference in temperature . between the air on the two aides), and are baaed on an outside wind velocity of IS mph. Heat Transmission Coefficients of Building Materials 193 Table 15. 1' Coefficients of Transmission (U) of Flat Roofs Covered with Built-up Roofing. With Lath and Plaster Ceilings" (See Table 14 for Flat Roofs with No Ceilings) * 87$ per cent gypsum, 12| per cent wood fiber. Thickness indicated includes i in. gypsum board. e Nominal thicknesses specified--actual thicknesses used in calculations. 6 Nominal thicknesses specified--actual thicknesses used in calculations.