Timber Roof Beam Span Tables

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

Timber roof beam span tables.

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure. The figures are based on quality materials. Also available for the android os.

View allowable load tables. View joist rafter tables. 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. Window door garage door headers supporting roof loads only.

View size selection tables. 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. Span calculator for wood joists and rafters also available for the android os. Notches are not to exceed 0 125 of the depth of the joist and are to be located between 0 07 and 0 25 of the span from the support.

For lesser grades spans should be shorter. Window door garage door headers supporting roof wall floor loads. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. The tables below give maximum spans for rafters and beams.

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Simplified span tables for southern pine lumber and glued laminated timber glulam headers beams and girders. These span tables apply only to flat roof and roof with a slope of up to 10 degrees.