Also available for the android os.
Lumber spans for roofs.
1 ft 0 3048 m.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.
1 psf lb f ft 2 47 88 n m 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.
Here we have a wood framed gable roof.
Span calculator for wood joists and rafters also available for the android os.
Live load is weight of furniture wind snow and more.
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 image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.
The tables below give maximum spans for rafters and beams.
2 are indicated below.
Floor beam span tables of residential structural design we will now look at roof rafter and beam design.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
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.
Wood beam calculator american wood council website rafter and joist span faq.
The figures are based on quality materials.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
Let s consider a basic gable wood roof framing design.