The full version allows any size.
Flat roof joist span c24.
1 psf lb f ft 2 47 88 n m 2.
Dead load weight of structure and fixed loads 15 lbs ft 2.
Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.
Also available for the android os.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
Usually 400 450 or 600mm but any value can be used up to 610mm max.
Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.
Span calculator for wood joists and rafters also available for the android os.
Rafter and joist span faq.
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 example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine.
Flat roof joist calculator.
Timber floor joists shall be adequate for the spans and loads and be correctly installed.
2 are indicated below.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.
This is the distance between joist centres.
1 enter joist details 1 1 span and joist spacing.
These span tables apply only to flat roof and roof with a slope of up to 10 degrees.
This demo version is fixed at 1m clear span.
Solid timber joist sizes are provided in the bs 8103 3 span tables.
1 ft 0 3048 m.
Live load is weight of furniture wind snow and more.
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.
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.
