Flat Roof Roof Joist Span Calculator Uk

This demo version is fixed at 1m clear span.

Flat roof roof joist span calculator uk.

These spans were calculated using our flat roof joist calculation engine. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. These span tables are the equivalent of other industry standard span tables and are calculated to the same standards.

Click on a span to generate a full calculation you can adjust the exact span. 1 enter joist details 1 1 span and joist spacing. Flat roof joist calculator. 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.

Usually 400 450 or 600mm but. Other span tables are based on the guidance given in bs 5268 7 1 which is a uniformly distributed load of 1 5kn m for spans greater than 2400 mm and 3 6 kn load per metre width of floor for spans less than 2400 mm to ensure that very small joist sizes do not result from the calculations for smaller spans. This span table is to the format and methodology given in bs 5268 7 2. Span calculator for wood joists and rafters also available for the android os.

Suitable for uk building regulation approval. 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. 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. This is the distance between joist centres.

Joists under each partition. Surveyors span tables for designing roof rafters.