This span table is to the format and methodology given in bs 5268 7 2.
Flat roof joist span.
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.
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.
Tables 1 and 2 in this chapter are derived from the trada technology ltd.
Eurocode 5 span tables for solid timber members in floors ceilings and roofs for dwellings 3rd edition.
1 ft 0 3048 m.
These spans were calculated using our flat roof joist calculation engine.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
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.
This is the distance between joist centres.
The section sizes are based on regularised als or cls timber.
This table uses commonly available uk regularised timber depths.
2 are indicated below.
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.
Span calculator for wood joists and rafters also available for the android os.
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.
For timber floors between homes.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
Also available for the android os.
Use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size.
Dead load weight of structure and fixed loads 15 lbs ft 2.
Live load is weight of furniture wind snow and more.
1 psf lb f ft 2 47 88 n m 2.