Porch Roof Header Span 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.

Porch roof header span table.

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. Jan 15 2017 a simple buying guide for beams and rafters that support patio roofs. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Window door garage door headers supporting roof loads only.

The total load is 4 000 pounds. According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2. For a porch roof the beam needs to be. Includes size and spacing tables for load bearing and links to related articles.

For the initial calculation f can be estimated at 1 000. It is pressure treated as well. In the example the beam spans the 10 foot width of the roof. Anything 5 and above we always at least double cripple.

The house is timberframe and the perimeter beam header is rough sawn full dimension 6x14 dense doug fir. Calculating loads on headers and beams. I have a corner porch with 16 foot spans and a hip roof. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.

On longer spans the beam may require much more bearing space as indicated by this table. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. The figures are based on quality materials. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

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. View joist rafter tables.