Maximum clear span of rafters for roof pitch 15°–22.5° with imposed load 1.00 kN/m²

Table 4B.17 Maximum clear span of rafters (m); Roof pitch more than 15° but not more than 22.5°; Imposed load 1.00 kN/m²; Timber strength class C24 Dead Load [kN/m²] excluding the self weight of the rafter Size of rafter (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 rafters (mm) | 400 450 600 | 400 450 600 | 400 450 600 38 x 100 | 2.28 2.19 1.99 | 2.16 2.08 1.89 | 2.07 1.99 1.80 38 x 125 | 2.84 2.73 2.48 | 2.70 2.59 2.35 | 2.58 2.48 2.25 38 x 150 | 3.40 3.27 2.97 | 3.23 3.10 2.82 | 3.09 2.97 2.69 47 x 100 | 2.44 2.35 2.14 | 2.32 2.23 2.03 | 2.22 2.13 1.94 47 x 125 | 3.04 2.93 2.67 | 2.89 2.78 2.53 | 2.77 2.66 2.42 47 x 150 | 3.64 3.50 3.19 | 3.46 3.33 3.03 | 3.31 3.18 2.89 50 x 100 | 2.49 2.40 2.18 | 2.37 2.28 2.07 | 2.27 2.18 1.98 50 x 125 | 3.10 2.99 2.72 | 2.95 2.84 2.58 | 2.82 2.72 2.47 50 x 150 | 3.71 3.57 3.26 | 3.46 3.40 3.09 | 3.38 3.25 2.95 38 x 89 | 2.03 1.95 1.77 | 1.93 1.85 1.68 | 1.84 1.77 1.60 38 x 140 | 3.18 3.06 2.78 | 3.02 2.90 2.63 | 2.88 2.77 2.52