Flat Roof Timber Joist Span Tables

Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.

Flat roof timber joist span tables.

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. 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. Proprietary strutting is to be used in accordance with manufacturers recommendations. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.

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. These span tables apply only to flat roof and roof with a slope of up to 10 degrees. Wane as allowed in bs 4978 2007 a2 2017 is permitted in all sections included in these 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 timber floors between homes. View joist rafter tables. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. 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.

Span tables for solid timber joists. Eurocode 5 span tables for solid timber members in floors ceilings and roofs for dwellings 3rd edition. For pitched roofs flat roofs and ceiling joists. Joist spans over 4 5m provide 2 rows of strutting at third span positions.

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. Tables 1 and 2 in this chapter are derived from the trada technology ltd. Solid timber strutting to be at least 38mm thick and be a minimum of three quarters of the joist depth. Surveyors span tables for designing roof rafters.

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. They also tell you what the maximum spacing should be between each section or timber member size of joists mm clear span c16 joist m clear span c24 joist m 47 x 95 47 x 120 47 x 145 47 x 170 47 x 195 47 x. Joists are to have minimum end bearing of 40mm.