Roof Span Tables Uk

Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings.

Roof span tables uk.

Size of joists mm clear span c16 joist m clear span c24 joist m 47 x 95 47 x 120 47 x 145 47 x 170 47 x 195 47 x 220 1 77 2 40 2 89 3 38 3 87 4 36 2 05 2 67 3 22 3 77 4 31 4 85 assumptions at 400mm centers. Span tables for ceiling joists to bs 5268 7 3 span tables for flat roof joists to bs 5268 7 2 imposed loads of 0 75 kn m for maintenance and snow load are applicable where there is no permanent access no fixed ladder or staircase and most areas where the altitude does not exceed 100 metres refer to bs 6399 3. This span table is to the format and methodology given in bs 5268 7 2. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.

This table uses commonly available uk regularised timber depths. Maximum clear span of rafters in metres for roof pitches of between 15 and 45 degrees. Refer to approved document to part a of the building regulations on gov uk for heavier roofing materials or unusual loading conditions these tables may not be appropriate. They also tell you what the maximum spacing should be between each section or timber member.

Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. Surveyors span tables for designing roof rafters. Contact a building control officer for advice. These spans were calculated using our flat roof joist calculation engine.