View joist rafter tables.
Porch roof header span table.
For a porch roof the beam needs to be sized according to the maximum snow loads in your area and you must know enough about the porch design to determine how the load will be distributed and over what distance the beam will carry the load.
In the example the beam spans the 10 foot width of the roof.
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.
On longer spans the beam may require much more bearing space as indicated by this table.
Floor joist span use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size.
Window door garage door headers supporting roof loads only.
A 2 2x10 can span 10 feet and so on.
The total load is 4 000 pounds.
Anything 5 and above we always at least double cripple.
The numbers in gray indicate the distance between the support posts.
Tables providing size selections for various beam spans and loading combinations for southern pine dimension lumber and southern pine glued laminated timber are available for the following applications.
The tables below give maximum spans for rafters and beams.
Beams of more than one ply must be fastened together with either nails or bolts.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
The figures are based on quality materials.
Includes span tables for all load bearing locations and the number of jack studs.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
Window door garage door headers supporting roof wall floor loads.
Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope.
These charts are for 30 pound per square foot snow load on the roof.
All other data is available on page 121 of the 2012 international residential code.
According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
A double 2x12 beam can span 12 feet.
