Document jkBjdrZoaX2w9O83eDp0g03Z

130 CHAPTER 6 19.48 Guide Heat Transmission Coefficients of Building-Materials 131 Table 12.. Coefficients of Transmission (-J7)'of'Concrete Construction Floors and Ceilings Coefficients ore expressed in Btu per- (how)'(square foot) (Fahrenheit degree difference in temperature between the air on the two sides), and are based on still air (no wind) conditions,on both sides. type of. ceiling . ............................ TYPE OF FLOORING............... .......... 0R.1HU- Thickness ..OF. ... Concrete 1 (Itches) ..No . Flooring (Concrete . Bare) T2e or UphSt Terrasxo. Flooring" on Concrete ` Tile6 Directly . on Concrete Parquet* Flooring In Mastio on Concrete Double Wood Floor - -oh. Sleeper*1' D z - A B CDE No Celling-........ --..... -.................. H in. Plaster Applied to Underside of Concrete............... .................... ......... 3 6 10 . .. 3 6 10 0.68 . 0.59 030 ooo pop iSoetSi 0.59 0.52 0.44 0.66 . 0.58 0.49 0.60 0.53 0.45 0.45 0.25 1 0.41 033 2 036 _ 032 3 0.43 0.24 4 039 0.22 . 5: 034 031 6 Metal Lath and Plaster4--Suspended or Furred.... .......------------------------------- :. 3 6 10 0.38 027 . 0.37 030 ` 0.19 1 0.35 034 0.35 038 0.18 8 0.32 031 0.32 036 ; 0.17 * 9 Gypsum Board (H in.) and Plaster/-- Suspended or Furred...... ....... .......... ..... 3 6 10. 0.36 035 0.35 0.33 032 0.33 0.30 .. .039. . .0.30 ooo 0.19 10 0.18 11 . 0.17... 12 Insulating Board lath (M in.) and Plaster/ Suspended or Furred................ --____.... 3 6 10 0.25 0.24 0.25 031 0.15 13 0.23 033 0.23 030 . 0.15 . 14 022 031 0.22 0.19 0.14 15 `Thickness of tile assumed to be 1 in. ^Conductivity of Asphalt Tile assumed to be 3.1. Thickness of wood assumed to be ll/fa in.; thickness of mastic, H in. (k * 4.5).' Col. D*may also be used for concrete covered with carpet. * Based on in. yellow pine or hr sub-flooring and ls/6 in. hardwood finish-flooring with an air space between sub-floor and concrete. Thickness of plaster assumed to be % in. /Thickness of plaster assumed to.be In. *For other thicknesses of concrete, interpolate. 13.Table Coefficients of Transmission (U) of Concrete Floors on Ground with Various Types of Finish Flooring U -- 0.10a Btu per (hour) (square foot) (Fahrenheit degree temperature difference between the ground and the air over the floor). __ `Until more complete data are available, it is recommended that a coefficient of 0.10 be used for all types of concrete floors on the ground, with or without insulation. For basement wall below grade, use the same average coefficient (0.10). -A lower ground temperature should, however, be used for walls, than floors as explained in Chapter 14. For further data see A.S.H.V.E. Research Report No. 1213--Heat Loss Through Basement Walls and Floors, by F. C. Houghten, S. I. Taimuty, Carl Gutberlet and C. J. Brown (A.S.H.V.E. Transactions, Vol. 48; 1942, p. 369). exact compliance with specifications, and a factor of safety may' be employed as a precaution when it is judged desirable. Roof Coefficients Computations for wood shingle roofs applied over wood stripping are based on 1 by 4 in. wood strips, spaced 2 in. apart. Values for roofs containing Spanish and French clay roofing tile are assumed the same as for slate roofs. Values for pitched roofs' in Table 16 apply , where ffie roof; is oyer a heated attic or top floor so that the heat passes, directly through the roof structure, including any interior finish material.