Tables 1 and 2 in this chapter are derived from the trada technology ltd.
Flat roof timber span tables c24.
The section sizes are based on regularised als or cls timber.
These span tables apply only to flat roof and roof with a slope of up to 10 degrees.
Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
Surveyors span tables for designing roof rafters.
Stocked at all branches click here to download c24 strength class pdf document.
Flat roof with no permanent access and altitude not exceeding 100m 0 75 kn m udl 0 9 kn point load most areas exceeding 100m but not exceeding 200m excluding parts of scotland pennines north east england refer to bs 6399 3 1 kn m udl 0 9 kn point load.
Span tables for solid timber joists.
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.
C16 span table only stocked at our mitcham depot.
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.
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.
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.
Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.
Eurocode 5 span tables for solid timber members in floors ceilings and roofs for dwellings 3rd edition.
For timber floors between homes.
For pitched roofs flat roofs and ceiling joists.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
Click here to download c16 span table leaflet c24 span table our premium grade of carcassing is c24 graded.