Rafter Span Roof Truss Span Tables

View joist rafter tables.

Rafter span roof truss span tables.

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. Surveyors span tables for designing roof rafters. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.

This is based upon the span of the rafter horizontal span not total rafter length live and dead loads. 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. So this table could accommodate a house with a total rafter span or house width of 32 feet. The shapes and spans shown here represent only a fraction of the millions of designs processed by alpine engineers.

Also available for the android os. This rafter span calculator is species specific for douglas fir hemlock etc. 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.

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. For pitched roofs flat roofs and ceiling joists. Roof truss cost member design of a 22m span steel roof truss structville roof trusses design framing construction pryda new zealand floor joist span table roof trusses flooring pier and beam the complete guide to roof trusses design cost framing more roof trusses design framing construction pryda new zealand. Use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.

Span calculator for wood joists and rafters also available for the android os. To size joists and rafters use the maximum span tables for southern yellow pine. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. Straight line interpolation shall be permitted for intermediate spans and design values.

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. Rafter spans for southern yellow pine douglas fir and eastern spruce.