For the initial calculation f can be estimated at 1 000.
Patio roof beam span 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.
The figures are based on quality materials.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
Includes size and spacing tables for load bearing and links to related articles.
Jan 15 2017 a simple buying guide for beams and rafters that support patio roofs.
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.
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.
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.
A 4 by 10 can usually span up to 12 feet between posts.
Flat roof span tables allow for a maximum roof pitch of 5º.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts.
The smallest beams for patio covers are typically 4 by 6.
Use recommended minimum roof pitches as specified by roof sheet supplier.
The total load is 4 000 pounds.
The tables below give maximum spans for rafters and beams.
Posts these span tables are designed for a minimum post size of 50 x 50 x 2 5mm up to a maximum height of 3 0m.
F stands for the beam s fiber strength in bending which depends on the species of wood.
In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
Tables 7 12.
Spantec has prepared these tables for use by people skilled in the design and specification of the.
In the example the beam spans the 10 foot width of the roof.
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.
