Flat Roof Rafter Span Table

Surveyors span tables for designing roof rafters.

Flat roof rafter span table.

Span tables for flat roof joists to bs 5268 7 2 imposed loads of 0 75 kn m for maintenance and snow load are applicable where there is no permanent access no fixed ladder or staircase and most areas where the altitude does not exceed 100 metres refer to bs 6399 3. Loads are calculated in accordance with table 3 1 of as nzs 1170 1 2002. The imposed uniformly distributed live load in the main span. 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.

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. Also available for the android os. This is set by the roof use you selected in the previous screen and cannot be modified. Posts these span tables are designed for a minimum post size of 50 x 50 x 2 5mm up to a maximum height of 3 0m.

Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. Use recommended minimum roof pitches as specified by roof sheet supplier. 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. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.

Means that your shed should be no wider or longer depending on how you orientate your single sloped roof than 11. Therefore for gable roofed sheds the rafter span table is indicating how far a rafter can span half of your shed s width. Ceiling joist span 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.

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. 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. These span tables apply only to flat roof and roof with a slope of up to 10 degrees. For pitched roofs flat roofs and ceiling joists.

Flat roof span tables allow for a maximum roof pitch of 5º.