Pitched Roof Timber Span Tables

Required size for a given span.

Pitched roof timber span tables.

For simple construction such as domestic construction this can be determined from span table supplements in as1684 2 and as1684 3. For pitched roofs flat roofs and ceiling joists. They also tell you what the maximum spacing should be between each section or timber member. Span tables span tables can be used to determine the size of a timber member of a particular strength class required for a given span.

The section sizes are based on regularised als or cls timber. Pitched roof timber sizes the following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction. 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 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.

Click here for structural design calculations. Rafter spans for southern yellow pine douglas fir and eastern spruce. Tables 1 and 2 in this chapter are derived from the trada technology ltd. 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.

All the figures are. 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. Spacing should be interpreted as the centre to centre distance between adjacent parallel members. Span tables for solid timber joists.

For timber floors between homes. Roof load width rlw and floor load width flw can be determined from as1684 or from the images below. So this table could accommodate a house with a total rafter span or house width of 32 feet. Span tables allow users to choose an appropriate size and stress grade to achieve spanning needs.