Document Y8r8bKv43GG412XKeg12B8Dk

134 ' , , CHAPTER 6 . , 1946 Guide. Table 14. Coefficients of Transmission (If) of Flat Roofs Covered with Built- up Roofing. No Ceiling^Under Side of Roof Exposed (See Table 15 for Flat Roofs with Ceilings) . These coefficients ore expressed in Btu per (hour) (square foot) (Fahrenheit degree difference in temperature between the air on the two sides), and are based on an outside wind velocity of 16 mph. TYPE OF ROOF DECK Thickness op Roof Deck (Inches) No Insula tion INSULATION ON TOP OF. DECK (Covered with Built-Up Roofing) Insulating Bqasd (Thickness Below) COHKBOA-BD (Thickness Below) . X Id. , 1 In. IX In. 2 In.. 1 In. 1H In. 2 In. cuEs0 oa z A B C D E F G .H Flat Metal Roof Deck* iNrtiunw/ . yccK~ 1.06 . 039 . 034 . 0.18 0.14 0.23 0.17 0.13 1 Precast Cement Tfle /CAST EocriKC; /tut IMin. *jvpeoe.r/Jr` 0.84 037 034 0.17 0.14 032 0.16 0.13 2 Concrete ' ROOHNGj / tS-;'***-'- "Jf COIfCkRTE.'' 2 in. ' 4 in. 6 in. 0.82 036 034 0.17 0.14 032 046 0.13 3 0.72 034 033 0.17 0.13 031 0.16 0.12 4 0.65 033 032 0.16 0.13 031 0.15 0.12 5 Gypsum Fiber Con- crete* on.K in. Gypsum Board - iruoLfittom wtptnci /, etr/vny. &0AAP' '2K in3K in. \ 0.38 031 - 034 0.18 031 0.16. 0.14 0.13 ,0.12 ` 0.11 0.17 . 0.13 0.11 0.15 0.12 . 0.10 6 7 Wood* umi.iufiiuiiii.Vi . IuE2to22p2s2ZZ22ZZJ ' 1 in. IK in. 2inl 3 in. , 0.49. 038 - 030 0.15 0.12 0.19 , 0.14 T 0.12 8 , 037 034 0.17 0.14 0.11- 0.17 . 0.13'.: 0.11 9- 032 1 032 0.16 0.13 0.11 0.16 0.12 0.10 10 033 . 0.17 0.14 0.11 0.096- 0.13 0.11 0.091 11 "Coefficient of transmission of bare corrugated'iron (no roofing) is 1.50 Btu per (hour)(square foot of ' projected area)(Fahrenheit degree dinerence in temperature) based on an outside wind velocity of 15 mph. per cent gypsum', 12H per cent wood fiber. Thickness indicated includes H'in. gypsum board. Nominal thicknesses specified---actual thicknesses used in calculations. w Heat Transmission Coefficients of Building Materials ; 135 Table 15. Coefficients of Transmission (V) ofJ<lat Roofs Covered with Built-up Roofing. With Lath' and Plaster Ceilings3 . (See Table 14 for Flat Roofs with No Ceilings) These coefficients are expressed in Btu per (hour) (square foot) (Fahrenheit degree difference in temperature between the air on the two sides), and are based on an outside wind velocity of 15 mph. TYPE OF ROOF DECK INSULATION ON TOP OF DECK (COTEBXD WITH BUILT-Up ROOFING) ' Root; Deck (Inches) No ' Insula tion Insulating Board (Thickness Below) Kin- IK In- CORKBOAHD (Thickness Belcrw) IK In. Flat Metal Roof Deck IMIOUTMII/ ppOFIKtfi Precast Cement Tile `T/UrfOKT^jr* IK in. f\AH^ ' nois R.flOF1N<S 2 2 in. 4 in. 0.42 '0.26 0.19 0.14 0.12 0.18 0.14 0.11 0.40y1 <0.25 0.18 0.14 0.12 0.17 0.13 0.11 037 034. 0.18 0.14 0.11 0.17 0.13 0.11 Gypsum Fiber Con crete* on K in. Gypsum Board' lM/ULAftfin/ itdari tiGx. \uJsrtrfTrrjJs m i 2K in. ,3M in- 037 0.19 0.15 0.12 0.10 0.14 0.12 0.097 033 0.17 .0.14 . 0.11 0.097 0.13 0.11 0.091 Wood* UimATiffTti ROtFlflfj / W 09O`/ IK in 2 in. 3 in. 031 r031 0.16 0.13 0.11 0.15 0.12 0.10 036 0.19 0.15 0.12 0.10 0.14- 0.11 0.095 0341 0.17 0.14 0.11 0.097 0.13 0.11. 0.092 0.18 0.14 0.12 0.10 0.087 0.11 04)95 0.082 Calculations based on nietal lath and-plaster ceilings, but coefficients may be used with sufficient accuracy for gypsum lath or wood lath and plaster ceilings. It is assumed that there is an air space between the under side of the roof deck and the upper side of the ceiling. *87>$ per cent gypsum. 12K per cent wood fiber. Thickness indicated includes K in. gypsum board Nominal thicknesses'specified--^actual thicknesses used in calculations. .