Roof Truss Span Tables

72 5 0 mi ni m u m girder floor truss floor truss jacks a a bearing wall girder floor truss floor truss jacks bearing wall cantilevered floor truss two 2x rim joists 24 max.

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. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Span calculator for wood joists and rafters also available for the android os. View joist rafter tables.

1 spans shown in charts are in feet. Straight line interpolation shall be permitted for intermediate spans and design values. 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. 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. Typical roof truss design spans general notes. And parallel to floor truss span strongback lateral supports 24 max. The more complex the truss framework is the greater quantity of these joints will be required.

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. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. Roof truss span tables. Roof floor truss manual 7 31 08 10 43 am page 12.

Keep in mind that these tables are for estimations only. The load span tables shown below demonstrate only a tiny subset of the possible combinations available with trussteel cfs roof trusses. Every trussteel roof truss is a custom design based upon the unique load span bearing use and code criteria of a particular project. The same thing is true for the bridge of the truss.

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Joist and rafter span tables. Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. They have not been updated for the change in lumber values within the last decade.