Technical Booklet D Structure·Page 45·Table 4B.27
Table 4B.27: Maximum clear span of rafters
This table provides maximum clear spans in metres for timber rafters at roof pitches between 30° and 45°, with an imposed load of 0.75 kN/m² and timber strength class C16, varying by dead load and rafter spacing.
Table 4B.27 Maximum clear span of rafters (m); Roof pitch more than 30° but not more than 45°; Imposed load 0.75 kN/m2; Timber strength class C16 C16
Dead Load [kN/m2 ] excluding the self weight of the rafter
Size of rafter (mm): 38 x 100, 38 x 125, 38 x 150, 47 x 100, 47 x 125, 47 x 150, 50 x 100, 50 x 125, 50 x 150, 38 x 89, 38 x 140, CLS/ALS
Spacing of rafters (mm): 400, 450, 600
Dead load categories: 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
Spans range from 1.50 m to 4.00 m depending on rafter size, spacing, and dead load.
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