The tables below give maximum spans for rafters and beams.
Roof beam span tables canada.
Beam and joist span tables built up wood floor beams supporting one floor in a house maximum spans for uniformly distributed loads species and grade supported built up beam size joist length 3 2x8 4 2x8 3 2x10 4 2x10 3 2x12 4 2x12 8 9 8 11 2 11 10 13 8 13 8 15 10 10 8 8 10 0 10 7 12 2 12 3 14 2.
Tables a 1 to a 16 cover only the most com mon configurations.
Although all possible efforts have been made to ensure that the information from this tool is accurate the cwc cannot guarantee the completeness accuracy or exactness of the information.
Dimensional lumber deck beam span chart.
Refer to sfpa s publication southern pine headers beams download in publications that includes all size selection and allowable load tables.
The national building code references the span book as follows.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
Loading conditions are detailed below.
Also available for the android os.
On longer spans the beam may require much more bearing space as indicated by this table.
Span calculator for wood joists and rafters also available for the android os.
The span book is a supplement to the wood joist rafter and beam spans found in the national building code of canada.
The figures are based on quality materials.
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.
For each application a pdf download is available.
When supporting joists that span 12 feet with no overhang beyond the beam a double ply beam can span in feet a value equal to its depth in inches.
The canadian wood council s beam calculator has been developed for the purpose of information only.
Also see assumptions for table development.
A 2 2x10 can span 10 feet and so on.
According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
The numbers in gray indicate the distance between the support posts.
A double 2x12 beam can span 12 feet.
Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure.
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.
