Roof Beam Span

Let s consider a basic gable wood roof framing design.

Roof beam span.

For the initial calculation f can be estimated at 1 000. Dimensional lumber deck beam span chart. 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.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. 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. Anything 5 and above we always at least double cripple. L stands for the span of the beam in feet.

Here we have a wood framed gable roof. The numbers in gray indicate the distance between the support posts. Beams of more than one ply must be fastened together with either nails or bolts. According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2.

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. Also available for the android os. F stands for the beam s fiber strength in bending which depends on the species of wood. This post may contain affiliate links.

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 lengths and sizes of joists vary depending on the species and quality of the lumber used. 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. Window door garage door headers supporting roof loads only.

Continuing on from part 3. In the example the beam spans the 10 foot width of the roof. The total load is 4 000 pounds. A 2 2x10 can span 10 feet and so on.

Window door garage door headers supporting roof wall floor loads. A double 2x12 beam can span 12 feet. Patio roof maximum beam rafter spans. For more information see our disclosures here.

Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Wood beam calculator american wood council website rafter and joist span faq. Fill in the parts of the formula that are already known.