Rafter Span Roof Truss Span Tables

Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.

Rafter span roof truss span tables.

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. View joist rafter tables. Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings. Also available for the android os.

Rafter spans for southern yellow pine douglas fir and eastern spruce. Alpine truss designs are engineered to meet specific span configuration and load conditions. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter. This rafter span calculator is species specific for douglas fir hemlock etc.

So this table could accommodate a house with a total rafter span or house width of 32 feet. For pitched roofs flat roofs and ceiling joists. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. This is based upon the span of the rafter horizontal span not total rafter length live and dead loads.

The shapes and spans shown here represent only a fraction of the millions of designs processed by alpine engineers. Use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. Surveyors span tables for designing roof rafters. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.

More roof calculators roof truss calculator how to cut rafters. 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. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. The spans in this table are based on a maximum supported rafter span of 16 feet where the supported span is the total horizontal distance spanned by the roof rafters divided in half not the diagonal distance or the length of the rafter.

Total load psf duration factor live load psf roof type 55 1 15 40 snow shingle 55 1 15 30 snow tile 47 1 15 30 snow shingle 40 1 15 20. To size joists and rafters use the maximum span tables for southern yellow pine.