Roof Beam Span

Floor beam span tables of residential structural design we will now look at roof rafter and beam design.

Roof beam span. Fill in the parts of the formula that are already known. According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2. The numbers in gray indicate the distance between the support posts. 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.

For the initial calculation f can be estimated at 1 000. Here we have a wood framed gable roof. Also available for the android os. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.

The lengths and sizes of joists vary depending on the species and quality of the lumber used. The total load is 4 000 pounds. For more information see our disclosures here. In the example the beam spans the 10 foot width of the roof.

On longer spans the beam may require much more bearing space as indicated by this table. Window door garage door headers supporting roof loads only. Anything 5 and above we always at least double cripple. Let s consider a basic gable wood roof framing design.

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. Patio roof maximum beam rafter spans. Dimensional lumber deck beam span chart. Window door garage door headers supporting roof wall floor loads.

Span calculator for wood joists and rafters also available for the android os. A 2 2x10 can span 10 feet and so on. An essential part of planning a patio roof or gazebo project is determining the number size and spacing of rafters beams and posts according to the loads they will carry. 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.

Wood beam calculator american wood council website rafter and joist span faq. When supporting joists that span 12 feet with no overhang beyond the beam a double ply beam can span in feet a value equal to its depth in inches. Designing with roof rafter span tables lvl 2 0e 2900fb power beam anthony forest s co raising ceiling joists jlc roofdek manual structural roof decking and trays. F stands for the beam s fiber strength in bending which depends on the species of wood.

Continuing on from part 3. For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. A double 2x12 beam can span 12 feet.