Flat Roof Joist Span Chart

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

Flat roof joist span chart.

1 enter joist details 1 1 span and joist spacing. For roof live loads of 12 psf or 16 psf table multiply tabulated multiply required number span by e value by 12 psf 16 psf 12 psf 16 psf r 1 1 17 1 07 0 96 0 99 r 5 1 14 1 06 0 89 0 96. Flat roof joist calculator. Use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.

This is the distance between joist centres. Spans and required e values tabulated for 20 psf shall be permitted to be adjusted in accordance with the fol lowing table. 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. This demo version is fixed at 1m clear span.

Also available for the android os. 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. Floor joist span use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size. Usually 400 450 or 600mm but any value can be used up to 610mm max.

Roof rafter span use this table to determine the maximum lengths of roof rafters. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.