Flat Roof Joist Span

Use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size.

Flat roof joist span.

This is the distance between joist centres. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. This table uses commonly available uk regularised timber depths.

Also available for the android os. 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. Live load is weight of furniture wind snow and more. 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.

This span table is to the format and methodology given in bs 5268 7 2. These span tables are the equivalent of other industry standard span tables and are calculated to the same standards. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Eurocode 5 span tables for solid timber members in floors ceilings and roofs for dwellings 3rd edition.

1 psf lb f ft 2 47 88 n m 2. Usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size automatically calculate sizes suitable for supporting the loads below. 2 are indicated below. Span tables for solid timber joists.

For timber floors between homes. 1 ft 0 3048 m. Span calculator for wood joists and rafters also available for the android os. These spans were calculated using our flat roof joist calculation engine.

The section sizes are based on regularised als or cls timber. 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.