Porch Roof Header Span Table

View joist rafter tables.

Porch roof header span table.

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. These charts are for 30 pound per square foot snow load on 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. Anything 5 and above we always at least double cripple.

For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. The tables below give maximum spans for rafters and beams. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Includes span tables for all load bearing locations and the number of jack studs.

The figures are based on quality materials. All other data is available on page 121 of the 2012 international residential code. In the example the beam spans the 10 foot width of the roof. 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.

Window door garage door headers supporting roof loads only. Beams of more than one ply must be fastened together with either nails or bolts. 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 wall floor loads.

Roof ceiling and one clear span floor 4 2x12 9 11 2 8 7 2 7 8 2 fccip 425 main st ste 25 greenfield ma 01301 3393 fccip staff phone. Span charts and 2012 irc building codes for girders and headers. According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2. Girder spans and header spans for exterior bearing walls maximum spans for douglas fir larch hem fir southern pine and spruce pine fir and required number of jack studs.

On longer spans the beam may require much more bearing space as indicated by this table.