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.
Timber roof span tables uk.
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.
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.
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.
These span tables apply only to flat roof and roof with a slope of up to 10 degrees.
For timber floors between homes.
Span table 0 75 kn m.
Tables 1 and 2 in this chapter are derived from the trada technology ltd.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
All the figures are based on roofing tiles or slates laid on timber laths over sarking felt.
Span tables for rafters to bs 5268 7 5 imposed loads of 0 75 kn m snow load are applicable to most areas where the altitude does not exceed.
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.
15 or more but less than 22 5.
Pitched roof timber sizes.
The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction.
Eurocode 5 span tables for solid timber members in floors ceilings and roofs for dwellings 3rd edition.
The section sizes are based on regularised als or cls timber.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
Ceiling joists flat roof joists rafters purlin span tables rafters.
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.
Span tables for solid timber joists.
For pitched roofs flat roofs and ceiling joists.