For lesser grades spans should be shorter.
Roof beam span tables canada.
Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure.
Anything 5 and above we always at least double cripple.
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.
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.
On longer spans the beam may require much more bearing space as indicated by this table.
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.
Loading conditions are detailed below.
Refer to sfpa s publication southern pine headers beams download in publications that includes all size selection and allowable load tables.
A 2 2x10 can span 10 feet and so on.
Tables in the span book and the national building code were both generated by the canadian wood council.
The numbers in gray indicate the distance between the support posts.
The span book is a supplement to the wood joist rafter and beam spans found in the national building code of canada.
For each application a pdf download is available.
A double 2x12 beam can span 12 feet.
Dimensional lumber deck beam span chart.
According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2.
Span calculator for wood joists and rafters also available for the android os.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
The national building code references the span book as follows.
Tables a 1 to a 16 cover only the most com mon configurations.
The canadian wood council s beam calculator has been developed for the purpose of information only.
Also available for the android os.
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.
Also see assumptions for table development.
The figures are based on quality materials.
