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 220 1 77 2 40 2 89 3 38 3 87 4 36 2 04 2 75 3 47 4 20 4 93 5 66 floor joists flat roof joists assumptions at 400mm centers supporting permanent load.
Flat roof timber span tables c24.
Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1.
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.
Click here to download c16 span table leaflet c24 span table our premium grade of carcassing is c24 graded.
These span tables apply only to flat roof and roof with a slope of up to 10 degrees.
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 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.
Maximum clear span of rafters in metres for roof pitches of between 15.
Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.
Stocked at all branches click here to download c24 strength class pdf document.
Pitched roof timber sizes.
For pitched roofs flat roofs and ceiling joists.
The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction.
C16 span table only stocked at our mitcham depot.
All the figures are based on roofing tiles or slates laid on timber laths over sarking felt.
Flat roof joists rafters purlin.
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.
Timber to be covered these span.
Span tables span tables can be used to determine the size of a timber member of a particular.