SJI publishes loading tables for K-series (short span). LH-series (long span), and DLH-series (deep long span) joist girders. The K-series joists are available in depths FIGURE 8.24 Open-web steel joist with (a) ceiling extension. (b) extended end. (Courtesy of Steel Joist Institute.) of 8 to 30 in and spans of 8 to 60 ft in 13 different chord weights to sustain uniform loads along the span as high as 550 lb / ft. LH-series joists are available in depths from 18 to 48 in and spans of 25 to 96 ft in six different chord weights capable of supporting total loads of 12,000 to 57,600 lb. DLH-series joists are available in depths of 52 to 72 in and spans from 89 to 144 ft in 17 different chord weights with total-load capacities of 26,700 to 80,200 lb. Load capacities in the foregoing were based on a maximum allowable tensile strength of 30 ksi, which calls for high-strength, low-alloy steel having a specified minimum yield strength of 50 ksi or cold-formed steel having the same yield strength. Fire resistance ratings of 1, 11/2, 2, and 3 hours are possible using concrete floors above decks as thin as 2 in and as thick as 31/2 in with various types of ceiling protection systems. The Steel Joist Institute identifies such ceiling protection systems as exposed grids, concealed grids, gypsum board, cementitious, or sprayed

Allowable bearing pressurea Maximum allowable bearing pressureb Massive crystalline bedrock 4,000 psf (200 kPa) 12,000 psf (600 kPa) Sedimentary and foliated rock 2,000 psf (100 kPa) 6,000 psf (300 kPa) Gravel and sandy gravel (GW, GP) 2,000 psf (100 kPa) 6,000 psf (300 kPa) Nonplastic soil: sands, silts, and NP silt (GM, SW, SP, SM)c 1,500 psf (75 kPa) 4,500 psf (220 kPa) Plastic soil: silts and clays (ML, MH, SC, CL, CH)c 1,000 psf (50 kPa) 3,000 psf (150 kPa)d aMinimum footing width and embedment depth equals 1 ft (0.3 m). bAn increase of 20% of the allowable bearing pressure is allowed for each additional foot (0.3 m) of width or depth up to the maximum allowable bearing pressures listed in Column 3. An exception is plastic soil, see note d. c Group symbols from Table 6.8. dNo increase in the allowable bearing pressure is allowed for an increase in width of the footing. For dense or stiff soils, allowable bearing values in this table are generally conservative. For very loose or very soft soils, the allowable bearing values may be too high. Source: Data from Uniform Building Code (1997) There are many charts, graphs, and figures that present bearing capacity factors developed by different engineers and researchers based on varying assumptions. For example, Fig. 6.28 presents bearing capacity factors Nc, N, and Nq , which automatically incorporate allowance for punching and local shear failure. Another example is Fig. 6.29, which presents bearing capacity factors that have not been adjusted for punching or local shear failure. Figure 6.29 also presents the bearing capacity equations for square, rectangular, and circular footings. The equations for granular soil (i.e., cohesionless soil, c  0) and for a total stress analysis for cohesive soil (i.e.,   0 and c  su) are also shown in Fig. 6.29. Other Footing Loads. In addition to the vertical load acting on the footing, it may also be subjected to a lateral load. A common procedure is to treat lateral loads separately and resist the lateral loads by using the soil pressure acting on the sides of the footing (passive pressure) and the frictional resistance along the bottom

FIGURE 12.1 Built-up roofing over two layers of preformed insulation board. Three plies of asphalt-impregnated glass-fiber felt, embedded in a continuous application of hot asphalt, overlay a base sheet adhered with asphalt to the insulation. Aggregate surfacing, about 3/8 in in diameter, is spread in the top flood coat of asphalt. (NRCA Roofing and Waterproofing Manual.) FIGURE 12.2 Protected-membrane roof with aggregate and insulation placed over, instead of under, the built-up membrane. Bitumen may be asphalt or coal tar. Roofing asphalt is a derivative of petroleum. It is described in ASTM Standard D312, which includes specifications for Types I, II, III, and IV. Each type has a different softening-point range, which should be considered by the specifier when specifying the type of asphalt to be used. Coal tar, described in ASTM D450, is a derivative of the production of coke from coal. Type I is referred to as old-style pitch. Type II is used for below-grade waterproofing. Type III, or coal-tar bitumen, was developed to be less of an irritant during application than Type I; however, Type III is no longer produced. Felts are sheet materials used to reinforce waterproofing and roofing membranes. The predominant type of felt used is glass fiber although organic felts are still commonly used in the construction of coal-tar systems. Polyester is an alternative type of felt. Asbestos felts were used in the past but are no longer produced in the