Maximum clear span of flat roof joists for access only – Imposed load 1.00 kN/m²

Table 4B.37 Maximum clear span of flat roof joists; Access only for cleaning and maintenance; Imposed load 1.00 kN/m²; Timber strength class C16 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 120 | 2.37 2.34 2.25 | 2.25 2.21 2.11 | 2.16 2.11 2.01 38 x 145 | 3.02 2.97 2.75 | 2.85 2.80 2.61 | 2.72 2.66 2.49 38 x 170 | 3.62 3.49 3.17 | 3.41 3.31 3.01 | 3.24 3.17 2.88 38 x 195 | 4.15 3.99 3.63 | 3.94 3.79 3.45 | 3.77 3.63 3.29 38 x 220 | 4.67 4.49 4.09 | 4.44 4.27 3.88 | 4.25 4.09 3.71 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 2.45 | 2.47 2.43 2.31 | 2.36 2.31 2.19 47 x 145 | 3.30 3.24 2.95 | 3.12 3.06 2.80 | 2.96 2.90 2.68 47 x 170 | 3.88 3.74 3.40 | 3.69 3.56 3.23 | 3.53 3.40 3.09 47 x 195 | 4.44 4.27 3.89 | 4.23 4.07 3.70 | 4.05 3.89 3.54 47 x 220 | 4.99 4.81 4.38 | 4.75 4.58 4.17 | 4.55 4.38 3.99 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 2.50 | 2.53 2.49 2.37 | 2.42 2.37 2.25 50 x 145 | 3.39 3.31 3.01 | 3.19 3.13 2.86 | 3.04 2.97 2.73 50 x 170 | 3.96 3.81 3.47 | 3.77 3.63 3.30 | 3.61 3.47 3.16 50 x 195 | 4.53 4.36 3.97 | 4.31 4.15 3.78 | 4.13 3.97 3.61 50 x 220 | 5.09 4.90 4.47 | 4.85 4.67 4.25 | 4.65 4.47 4.07 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 2.70 | 2.79 2.74 2.57 | 2.66 2.61 2.46 63 x 145 | 3.70 3.56 3.25 | 3.50 3.39 3.09 | 3.33 3.25 2.95 63 x 170 | 4.26 4.10 3.74 | 4.06 3.91 3.56 | 3.89 3.74 3.41 63 x 195 | 4.86 4.69 4.28 | 4.64 4.47 4.07 | 4.45 4.28 3.90 63 x 220 | 5.46 5.27 4.82 | 5.21 5.02 4.59 | 5.00 4.82 4.39 75 x 120 | 3.17 3.12 2.86 | 3.00 2.94 2.72 | 2.86 2.80 2.60 75 x 145 | 3.90 3.76 3.44 | 3.72 3.59 3.27 | 3.56 3.44 3.13 75 x 170 | 4.49 4.33 3.96 | 4.29 4.13 3.77 | 4.11 3.96 3.61 75 x 195 | 5.13 4.95 4.53 | 4.89 4.72 4.31 | 4.70 4.53 4.13 75 x 220 | 5.76 5.56 5.09 | 5.50 5.30 4.85 | 5.28 5.09 4.65 38 x 140 | 2.84 2.79 2.62 | 2.68 2.63 2.48 | 2.56 2.51 2.37 38 x 184 | 3.92 3.77 3.43 | 3.73 3.58 3.25 | 3.56 3.43 3.11 CLS/ALS