Rafter Span Flat Roof Joist Span Tables

Maximum clear span of flat roof joists in metres for sc3 timber spacing between joists size of roof joist 400mm 450mm 600mm 47 x 97 1 84 1 81 1 74.

Rafter span flat roof joist span tables.

Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. 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.

Limited to span in inches divided by 360. Deflection for 30 psf live load. Surveyors span tables for designing roof rafters. 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.

Should refer to trada document span tables for solid timber members in floors ceilings and roofs excluding trussed rafter roofs for dwellings or ask your lbc surveyor for advice. Also available for the android os. For pitched roofs flat roofs and ceiling joists. Notches are not to exceed 0 125 of the depth of the joist and are to be located between 0 07 and 0 25 of the span from the support.

Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. Span tables for jois ts and rafters american wood council 4 span tables for joists and rafters american wood council design criteria. The tables below give maximum spans for rafters and beams. 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.

Span calculator for wood joists and rafters also available for the android os. Strength live load of 30 psf plus dead load of 10 psf determines the required bending design value. These span tables apply only to flat roof and roof with a slope of up to 10 degrees.