Flat Roof Joist Span Tables

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.

Flat roof joist span 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. Solid timber joist sizes are provided in the bs 8103 3 span tables. 1 enter joist details 1 1 span and joist spacing. They also tell you what the maximum spacing should be between each section or timber member.

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Flat roof joist calculator. Joists rafters simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Span tables can be used to determine the size of a timber member of a particular strength class required for a given span.

These span tables apply only to flat roof and roof with a slope of up to 10 degrees. Timber floor joists shall be adequate for the spans and loads and be correctly installed. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center.

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. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter. Span tables all span tables. Joist and rafter span tables.

Straight line interpolation shall be permitted for intermediate spans and design values. 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. Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Span tables for solid timber joists.

View joist rafter tables. The full version allows any size.