Porch Roof Beam Span 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.

Porch roof beam span table. View joist rafter tables. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Table 9 1 in span tables for joists and rafters figure 5 gives a required compression value of 237 psi for a span of 16 feet and bearing length of 1 5 inches. The smallest beams for patio covers are typically 4 by 6.

In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts. Includes size and spacing tables for load bearing and links to related articles. Download a pdf. 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.

The figures are based on quality materials. In the article it is stated that a 12 joist span corresponds to the double beam span a length equal to the 2x width. However this seems to match the 6 joist span column of the table. 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.

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. In the example the beam spans the 10 foot width of the roof. Tables 7 12. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.

Jan 15 2017 a simple buying guide for beams and rafters that support patio roofs. Michael t 5 17 2017 12 53 19 am reply. The total load is 4 000 pounds. For the initial calculation f can be estimated at 1 000.

The tables below give maximum spans for rafters and beams. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. A 4 by 10 can usually span up to 12 feet between posts. F stands for the beam s fiber strength in bending which depends on the species of wood.

The tables permit a bearing length of up to 3 5 inches but since 1 5 is probably the worst case that you ll encounter for joist or rafter bearing it s a safe value. Fill in the parts of the formula that are already known. If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts.