Maximum clear span of flat roof joists for access and cleaning

Table 4B.35 Maximum clear span of flat roof joists (m); Access only or cleaning and maintenance; Imposed load 0.75 kN/m²; Timber strength class C16 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 97: 1.74 1.72 1.67 | 1.67 1.64 1.58 | 1.61 1.58 1.51 38 x 122: 2.37 2.34 2.25 | 2.25 2.21 2.11 | 2.16 2.11 2.01 38 x 147: 3.02 2.97 2.85 | 2.85 2.80 2.66 | 2.72 2.66 2.51 38 x 170: 3.63 3.57 3.37 | 3.41 3.34 3.17 | 3.24 3.17 2.98 38 x 195: 4.30 4.23 3.86 | 4.03 3.94 3.63 | 3.81 3.72 3.45 38 x 220: 4.94 4.76 4.34 | 4.64 4.49 4.09 | 4.38 4.27 3.88 47 x 97: 1.92 1.90 1.84 | 1.84 1.81 1.74 | 1.77 1.74 1.65 47 x 120: 2.60 2.57 2.47 | 2.47 2.43 2.31 | 2.36 2.31 2.19 47 x 145: 3.30 3.25 3.12 | 3.12 3.06 2.90 | 2.96 2.90 2.74 47 x 170: 3.96 3.89 3.61 | 3.72 3.64 3.40 | 3.53 3.44 3.23 47 x 195: 4.68 4.53 4.31 | 4.37 4.28 3.89 | 4.14 4.04 3.70 47 x 220: 5.28 5.09 4.65 | 4.99 4.81 4.38 | 4.75 4.58 4.17 50 x 97: 1.97 1.95 1.89 | 1.89 1.86 1.78 | 1.81 1.78 1.70 50 x 120: 2.67 2.64 2.53 | 2.53 2.49 2.37 | 2.42 2.37 2.25 50 x 145: 3.39 3.34 3.19 | 3.19 3.13 2.97 | 3.04 2.97 2.80 50 x 170: 4.06 3.99 3.69 | 3.81 3.73 3.47 | 3.61 3.53 3.30 50 x 195: 4.79 4.62 4.22 | 4.48 4.36 3.97 | 4.23 4.13 3.78 50 x 220: 5.38 5.19 4.74 | 5.09 4.90 4.47 | 4.85 4.67 4.25 63 x 97: 2.19 2.16 2.09 | 2.09 2.06 1.97 | 2.01 1.97 1.87 63 x 120: 2.95 2.91 2.79 | 2.79 2.74 2.61 | 2.66 2.61 2.47 63 x 145: 3.72 3.66 3.44 | 3.50 3.43 3.25 | 3.33 3.26 3.07 63 x 170: 4.44 4.35 3.97 | 4.16 4.07 3.74 | 3.95 3.85 3.56 63 x 195: 5.14 4.96 4.54 | 4.86 4.69 4.28 | 4.61 4.47 4.07 63 x 220: 5.77 5.57 5.10 | 5.46 5.27 4.82 | 5.21 5.02 4.59 75 x 120: 3.17 3.12 3.00 | 3.00 2.94 2.80 | 2.86 2.80 2.65 75 x 145: 3.98 3.92 3.64 | 3.75 3.67 3.44 | 3.56 3.48 3.27 75 x 170: 4.74 4.58 4.19 | 4.44 4.33 3.96 | 4.21 4.11 3.77 75 x 195: 5.42 5.23 4.79 | 5.13 4.95 4.53 | 4.89 4.72 4.31 75 x 220: 6.07 5.87 5.38 | 5.76 5.56 5.09 | 5.50 5.30 4.85 38 x 140: 2.84 2.79 2.68 | 2.68 2.63 2.51 | 2.56 2.51 2.37 38 x 184: 4.01 3.94 3.64 | 3.76 3.68 3.43 | 3.56 3.48 3.25 CLS/ALS