Timber Span Tables Flat Roof

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.

Timber span tables flat roof.

Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. 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. 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. For pitched roofs flat roofs and ceiling joists.

They also tell you what the maximum. Flat roof joists assumptions at 400mm centers supporting permanent load excluding self weight of joists up to 50kg m2. 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. 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.

Span tables flat roof joists 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.