Technical Booklet D Structure·Page 58·Table 4B.44
Maximum clear span of purlins supporting decking or sheeting (C24 timber) – Roof pitch more than 10° but not more than 35°
This table provides maximum clear spans in metres for timber purlins of strength class C24 supporting roof decking or sheeting, with an imposed load of 1.00 kN/m² and roof pitch between 10° and 35°. Spans are given for various purlin sizes, design spacings, and dead loads.
Table 4B.44 Maximum clear span of purlins supporting decking or sheeting; Roof pitch more than 10° but not more than 35°; Imposed load of 1.00 kN/m2; Timber strength class C24 C24
Dead Load [kN/m2] excluding the self weight of the purlin
Size of purlin (mm): 50 x 100, 50 x 125, 50 x 150, 50 x 175, 50 x 200, 50 x 225, 63 x 100, 63 x 125, 63 x 150, 63 x 175, 63 x 200, 63 x 225
Not more than 0.25 / More than 0.25 but not more than 0.50 / More than 0.50 but not more than 0.75
Design spacing of purlins (mm): 900, 1200, 1500, 1800, 2100, 2400 (repeated for each dead load range)
Detailed span values provided in tabular format as shown in source document.
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