For lesser grades spans should be shorter.
Shed roof span tables.
Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
View joist rafter tables.
R cb150 16 beam span table used w 3600 width of frame rafter span χ 6410 fascia beam span the cb150 16 beam achieves the 6000mm span for the fascia beam and can be used for the rafters.
There is no standard spacing it depends on what size of rafters you want to use and the span of your shed.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
For instance 2 grade 2x4s at 16 on center will span just over 9.
Joist and rafter span tables.
Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure.
The tables below give maximum spans for rafters and beams.
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.
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.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.