Timber Span Tables Flat Roof

Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.

Timber span tables flat roof.

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. Surveyors span tables for designing roof rafters. Flat roof joists assumptions at 400mm centers supporting permanent load excluding self weight of joists up to 50kg m2.

They also tell you what the maximum. 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. 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. 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 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.