Timber Roof Joist Span Tables

Surveyors span tables for designing roof rafters.

Timber roof joist span tables.

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Span tables span tables can be used to determine the size of a timber member of a particular strength class required for a given span. Solid timber joist sizes are provided in the bs 8103 3 span tables. Span calculator for wood joists and rafters also available for the android os.

Simplified span tables for southern pine lumber and glued laminated timber glulam headers beams and girders. 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. View allowable load tables. Where the tables do not apply or where there are concentrated loads floor joists should be designed by an engineer in accordance with technical requirement r5.

For pitched roofs flat roofs and ceiling joists. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. Timber floor joists shall be adequate for the spans and loads and be correctly installed. They also tell you what the maximum spacing should be between each section or timber member 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.

View size selection tables. Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. Also available for the android os. 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.

These span tables apply only to flat roof and roof with a slope of up to 10 degrees.