Flat Roof Joist Sizes C24

Building control guidance note planning regulations.

Flat roof joist sizes c24.

Timber to be covered these span tables do not apply to timber which is fully exposed to the elements. Flat roof joist calculator. This demo version is fixed at 1m clear span. 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.

These span tables apply only to flat roof and roof with a slope of up to 10 degrees. The full version allows any size. Joists under each partition. These tables can help calculate whether floor joists are strong enough to support themselves and the load they carry without the help of any walls underneath.

Timber floor joists shall be adequate for the spans and loads and be correctly installed. Enter a specific joist size 2 loadings dead load. Size of roof joists spacing of joists. Clear spans for flat roof joists in metres.

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. Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm 400mm 450mm 600mm. Solid timber joist sizes are provided in the bs 8103 3 span tables.

400mm 450mm 600mm 97 x 47 1 84 1 81 1 74 120 x 47 2 43 2 39 2 27 145 x 47 3 08 3 02 2 87. Where the tables do not apply or where there are concentrated loads floor joists should be designed by an engineer in accordance with technical requirement r5. Ceiling and flat roofs timber sizes and construction details. For pitched roofs flat roofs and ceiling joists.

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.