Dead load weight of structure and fixed loads 15 lbs ft 2.
Span flat roof joist wood.
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.
While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator.
Usually 400 450 or 600mm but any value can be used up to 610mm max.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
1 psf lb f ft 2 47 88 n m 2.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
Also available for the android os.
1 enter joist details 1 1 span and joist spacing.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
Common i joist applications i joists are used extensively in residential floor and roof framing.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
This is the distance between joist centres.
Because i joists are straight and true it s easier for builders to avoid crowning and maintain a level framing surface.
The full version allows any size.
These span tables apply only to flat roof and roof with a slope of up to 10 degrees.
Span calculator for wood joists and rafters also available for the android os.
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.
Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.
This demo version is fixed at 1m clear span.
Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.
1 ft 0 3048 m.
2 are indicated below.
Flat roof joist calculator.
