Patio Roof Beam Span Table

The tables below give maximum spans for rafters and beams.

Patio roof beam span table.

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. If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts. L stands for the span of the beam in feet. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

Fill in the parts of the formula that are already known. Spantec has prepared these tables for use by people skilled in the design and specification of the. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. For the initial calculation f can be estimated at 1 000.

Jan 15 2017 a simple buying guide for beams and rafters that support patio roofs. 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. Use recommended minimum roof pitches as specified by roof sheet supplier. The smallest beams for patio covers are typically 4 by 6.

In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. Flat roof span tables allow for a maximum roof pitch of 5º. The figures are based on quality materials. 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 total load is 4 000 pounds. Tables 7 12. 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.

For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Includes size and spacing tables for load bearing and links to related articles. In the example the beam spans the 10 foot width of the roof. 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.

In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts.