Roof Joists Span Tables

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

Roof joists span tables.

The tables below give maximum spans for rafters and beams. For lesser grades spans should be shorter. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. These span tables apply only to flat roof and roof with a slope of up to 10 degrees.

Joist span tables use these tables to determine lengths sizes and spacing of ceiling joists. Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Joist and rafter span tables. Span calculator for wood joists and rafters also available for the android os.

These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. 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. If this is the case with your structure use the floor joist table to determine maximum joist length load. Design information for all joists tji joist floor framing 24.

Joists rafters simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. View joist rafter tables. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.

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. 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. Straight line interpolation shall be permitted for intermediate spans and design values.

Design properties 16 floor span and load tables 17 allowable holes 18 roof span and load tables 19 cantilevers 20 21 framing connectors 22 23 section 3. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.