Flat Roof Joist Span

Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.

Flat roof joist span.

1 enter joist details 1 1 span and joist spacing. Dead load weight of structure and fixed loads 15 lbs ft 2. The full version allows any size. 1 psf lb f ft 2 47 88 n m 2.

1 ft 0 3048 m. For pitched roofs flat roofs and ceiling joists. Flat roof joist calculator. 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.

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. 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 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 excluding self weight of joists up to 50kg m2. Also available for the android os. This demo version is fixed at 1m clear span.

These span tables apply only to flat roof and roof with a slope of up to 10 degrees. This is the distance between joist centres. Usually 400 450 or 600mm but any value can be used up to 610mm max. Span calculator for wood joists and rafters also available for the android os.

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 47 x 120 2 43 2 39 2 27 47 x 145 3 08 3 02 2 87 47 x 170 3 75 3 67 3 42 47 x 195 4 41 4 31 3 92 47 x 220 5 04 4 85 4 41 75 x 170 4 50 4 38 3 99. 2 are indicated below. Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope. Use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size.

Live load is weight of furniture wind snow and more. 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. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. Surveyors span tables for designing roof rafters.