The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.
Roof framing on span of 50 feet.
Every trussteel roof truss is a custom design based upon the unique load span bearing use and code criteria of a particular project.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
Typical roof truss design spans general notes.
Rafter and joist span faq.
For roof live loads less than 20 pounds per square foot psf rafter spans and required e values tabulated for 20 psf shall be permitted to be adjusted in accordance with the fol lowing table.
In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.
For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.
6 12 2 12 40 43 59 42 49 62 45 56 66 48 57 71 6 12 2 5 12 37 38 52 38 44 57 41 50 61 44 52 66 6 12 3 12 33 33 45 35 38 52 38 43 56 40 46 60 6 12 3 5 12 28 28 38 32 32 44 34 37 50 36 39 54.
Use these two tables for.
Also available for the android os.
Spans in feet to out of bearing spans in feet to out of bearing.
Floor beam span tables of residential structural design we will now look at roof rafter and beam design.
The loads are based on adjusted roof snow loads from the governing building code.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.
There are also factors such as deflection elasticity and wood species that come in to play.
Consult local building codes for snow load capacity and reference the span tables for joists and rafters published by the american wood council awc as a general rule roofs that have a high human occupancy rate should be framed with rafters every 16.
Span calculator for wood joists and rafters also available for the android os.
The load span tables shown below demonstrate only a tiny subset of the possible combinations available with trussteel cfs roof trusses.
Let s consider a basic gable wood roof framing design.
Roof truss span tables alpine engineered products 15.
1 spans shown in charts.
Continuing on from part 3.
Here we have a wood framed gable roof.
The tables below give maximum spans for rafters and beams.