Technical Booklet D Structure·Page 48·Table 4B.32
Table 4B.32: Maximum clear span of purlins (pitched roofs)
This table provides maximum clear span values in metres for purlins with roof pitch between 30° and 45°, imposed load of 1.00 kN/m², and timber strength class C24, organized by purlin size, spacing, and dead load range.
Table 4B.32 Maximum clear span of purlins (m); Roof pitch more than 30° but not more than 45°; Imposed load 1.00 kN/m2; Timber strength class C24 excluding the self weight of the purlin
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
Design spacing of purlins (mm): 1500, 1800, 2100, 2400, 2700, 3000 (repeated for each dead load range)
47 x 150: 1.95, 1.83, 1.84
47 x 175: 2.27, 2.13, 2.01, 1.92, 1.83, 2.15, 2.01, 1.90, 1.80, 2.04, 1.91, 1.80
47 x 200: 2.60, 2.43, 2.30, 2.19, 2.09, 2.01, 2.45, 2.30, 2.17, 2.06, 1.97, 1.89, 2.33, 2.18, 2.06, 1.96, 1.87
47 x 225: 2.92, 2.73, 2.58, 2.46, 2.35, 2.26, 2.76, 2.58, 2.44, 2.32, 2.22, 2.13, 2.62, 2.45, 2.32, 2.20, 2.10, 1.89
63 x 125: 1.81
63 x 150: 2.16, 2.03, 1.92, 1.83, 2.05, 1.92, 1.81, 1.95, 1.83
63 x 175: 2.52, 2.36, 2.24, 2.13, 2.04, 1.97, 2.39, 2.24, 2.11, 2.01, 1.93, 1.85, 2.27, 2.13, 2.01, 1.91, 1.83
63 x 200: 2.88, 2.70, 2.56, 2.44, 2.33, 2.24, 2.72, 2.55, 2.41, 2.30, 2.20, 2.12, 2.59, 2.43, 2.30, 2.19, 2.09, 2.01
63 x 225: 3.23, 3.03, 2.87, 2.74, 2.62, 2.52, 3.06, 2.87, 2.71, 2.59, 2.48, 2.38, 2.92, 2.73, 2.58, 2.46, 2.35, 2.26
75 x 125: 1.92, 1.82
75 x 150: 2.30, 2.16, 2.04, 1.95, 1.87, 2.18, 2.04, 1.93, 1.84, 2.07, 1.94, 1.84
75 x 175: 2.68, 2.51, 2.38, 2.27, 2.18, 2.10, 2.54, 2.38, 2.25, 2.15, 2.06, 1.98, 2.42, 2.27, 2.14, 2.04, 1.96, 1.88
75 x 200: 3.06, 2.87, 2.72, 2.59, 2.49, 2.39, 2.89, 2.72, 2.57, 2.45, 2.35, 2.26, 2.76, 2.59, 2.45, 2.33, 2.23, 2.15
75 x 225: 3.43, 3.22, 3.06, 2.91, 2.79, 2.69, 3.25, 3.05, 2.89, 2.75, 2.64, 2.54, 3.10, 2.91, 2.75, 2.62, 2.51, 2.41
2 x 47 x 200: 3.46, 3.25, 3.08, 2.94, 2.82, 2.72, 3.28, 3.08, 2.92, 2.78, 2.67, 2.57, 3.13, 2.94, 2.78, 2.65, 2.54, 2.45
2 x 47 x 225: 3.88, 3.65, 3.46, 3.31, 3.17, 3.06, 3.68, 3.46, 3.28, 3.13, 3.00, 2.89, 3.51, 3.30, 3.13, 2.98, 2.86, 2.75
2 x 47 x 250: 4.30, 4.05, 3.84, 3.76, 3.52, 3.40, 4.08, 3.84, 3.64, 3.47, 3.33, 3.21, 3.90, 3.66, 3.47, 3.31, 3.18, 3.06
2 x 47 x 275: 4.73, 4.45, 4.22, 4.03, 3.87, 3.73, 4.48, 4.22, 4.00, 3.82, 3.66, 3.53, 4.28, 4.02, 3.81, 3.64, 3.49, 3.36
2 x 47 x 300: 5.15, 4.85, 4.60, 4.39, 4.22, 4.07, 4.89, 4.59, 4.36, 4.16, 3.99, 3.85, 4.67, 4.38, 4.16, 3.97, 3.80, 3.66
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