Roof Truss Span Tables

Joist and rafter span tables.

Roof truss span tables.

The load span tables shown below demonstrate only a tiny subset of the possible combinations available with trussteel cfs roof trusses. Also available for the android os. And parallel to floor truss span strongback lateral supports 24 max. These steel joints are needed to support the overall truss.

Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter. 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. View joist rafter tables.

Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Top chord 2x4 2x6 2x6 2x4 2x6 2x6 2x4 2x6 2x6 2x4 2x6 2x6 bottom chord 2x4 2x4 2x6 2x4 2x4 2x6 2x4 2x4 2x6 2x4 2x4 2x6 2 12 24 24 33 27 27 37 31 31 43 33 33 46 2 5 12 29 29 39 33 33 45 37 38 52 39 40 55 3 12 34 34 46 37 39 53 40 44 60 43 46 64 3 5 12 39 39 53 41 44 61 44 50 65 47 52 70 4 12 41 43 59 43 49 64 46 56 69 49 57 74 5 12 44 52 67 46 58 69 49 66 74 53 66 80 6 12 46 60 69 47 67 71 51 74 76 55 74 82 7 12 47 67 70 48. Span calculator for wood joists and rafters also available for the android os.

Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Keep in mind that these tables are for estimations only. Every trussteel roof truss is a custom design based upon the unique load span bearing use and code criteria of a particular project. Straight line interpolation shall be permitted for intermediate spans and design values.

Included are a series of representative roof truss span tables that will give you an idea of the truss spans available for a particular load condition load duration lumber type and truss configuration. 1 spans shown in charts are in feet. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. The same thing is true for the bridge of the truss.

The more complex the truss framework is the greater quantity of these joints will be required. Roof truss span tables. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. They have not been updated for the change in lumber values within the last decade.