Porch Roof Header Span Table

Window door garage door headers supporting roof wall floor loads.

Porch roof header span table.

According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2. 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. These charts are for 30 pound per square foot snow load on the roof. A double 2x12 beam can span 12 feet.

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. Beams of more than one ply must be fastened together with either nails or bolts. A 2 2x10 can span 10 feet and so on. Includes span tables for all load bearing locations and the number of jack studs.

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. All other data is available on page 121 of the 2012 international residential code. View joist rafter tables. The numbers in gray indicate the distance between the support posts.

For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. In the example the beam spans the 10 foot width of the roof. 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.

The total load is 4 000 pounds. The tables below give maximum spans for rafters and beams. Floor joist span use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size. On longer spans the beam may require much more bearing space as indicated by this table.

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. Dimensional lumber deck beam span chart. Window door garage door headers supporting roof loads only. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.