Maximum Imposed Load for Flat Roof Joists - Table 4B.39

Dead Load [kN/m2] excluding the self weight of the joist Size of joist (mm) Not more than 0.50 More than 0.50 but not more than 0.75 More than 0.75 but not more than 1.00 Spacing of joist (mm) 400 450 600 400 450 600 400 450 600 38 x 120 1.80 1.79 1.74 1.74 1.71 1.65 1.68 1.65 1.57 38 x 145 2.35 2.33 2.27 2.27 2.25 2.18 2.21 2.18 2.09 38 x 170 2.88 2.85 2.77 2.77 2.74 2.64 2.68 2.64 2.53 38 x 195 3.47 3.43 3.29 3.33 3.28 3.16 3.21 3.16 3.02 38 x 220 4.08 4.03 3.71 3.90 3.84 3.56 3.75 3.68 3.43 47 x 120 2.00 1.99 1.94 1.94 1.93 1.87 1.89 1.87 1.81 47 x 145 2.60 2.58 2.51 2.51 2.48 2.40 2.44 2.40 2.31 47 x 170 3.18 3.14 3.06 3.06 3.02 2.91 2.95 2.91 2.78 47 x 195 3.82 3.78 3.54 3.66 3.61 3.40 3.52 3.46 3.28 47 x 220 4.48 4.38 3.99 4.27 4.20 3.83 4.10 4.03 3.70 50 x 120 2.06 2.05 2.00 2.00 1.98 1.93 1.95 1.93 1.86 50 x 145 2.68 2.65 2.59 2.59 2.56 2.47 2.51 2.47 2.38 50 x 170 3.27 3.23 3.14 3.14 3.10 2.99 3.04 2.99 2.86 50 x 195 3.93 3.88 3.61 3.76 3.70 3.47 3.62 3.56 3.35 50 x 220 4.60 4.47 4.07 4.38 4.30 3.91 4.21 4.13 3.78 63 x 97 1.67 1.66 1.63 1.63 1.61 1.57 1.59 1.57 1.53 63 x 120 2.31 2.29 2.24 2.24 2.21 2.15 2.17 2.15 2.07 63 x 145 2.98 2.95 2.87 2.87 2.84 2.74 2.78 2.74 2.63 63 x 170 3.62 3.59 3.41 3.48 3.43 3.28 3.36 3.30 3.16 63 x 195 4.34 4.29 3.90 4.15 4.08 3.75 3.99 3.92 3.62 63 x 220 5.00 4.82 4.39 4.82 4.64 4.22 4.62 4.48 4.08 75 x 120 2.50 2.48 2.42 2.42 2.40 2.32 2.35 2.32 2.24 75 x 145 3.23 3.19 3.11 3.11 3.07 2.96 3.00 2.96 2.84 75 x 170 3.91 3.87 3.61 3.75 3.69 3.47 3.61 3.55 3.35 75 x 195 4.66 4.53 4.13 4.45 4.36 3.97 4.28 4.20 3.84 75 x 220 5.28 5.09 4.65 5.09 4.90 4.47 4.92 4.74 4.32 38 x 140 2.19 2.17 2.12 2.12 2.10 2.04 2.07 2.04 1.94 38 x 184 3.21 3.17 3.08 3.08 3.04 2.93 2.98 2.93 2.80 CLS/ALS; Access not limited to the purposes of cleaning and maintenance; 1.50 kN/m²; Timber strength class C16