Span Tables for Purlin Supporting Rafters (to BS 5268-7.6)

Imposed loads of 0.75 kN/m² snow load are applicable to most areas where the altitude does not exceed 100 metres (refer to BS 6399-3)

Imposed loads of 1 kN/m² snow load are applicable to most areas where the altitude exceeds 100 metres but does not exceed 200 metres, but excluding parts of Scotland, Pennines, North East England (refer to BS 6399-3)

Imposed load	Slope	Timber
0.75 kN/m²	15° or more but less than 22.5°	C16 timber
0.75 kN/m²	15° or more but less than 22.5°	C24 timber
0.75 kN/m²	22.5° or more but less than 30°	C16 timber
0.75 kN/m²	22.5° or more but less than 30°	C24 timber
0.75 kN/m²	30° or more but less than 45°	C16 timber
0.75 kN/m²	30° or more but less than 45°	C24 timber
1 kN/m²	15° or more but less than 22.5°	C16 timber
1 kN/m²	15° or more but less than 22.5°	C24 timber
1 kN/m²	22.5° or more but less than 30°	C16 timber
1 kN/m²	22.5° or more but less than 30°	C24 timber
1 kN/m²	30° or more but less than 45°	C16 timber
1 kN/m²	30° or more but less than 45°	C24 timber

Span Tables for Purlin Supporting Rafters (to BS 5268-7.6)

Calculators

Span tables

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