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.
Roof hip spans.
Roof load width rlw and floor load width flw can be determined from as1684 or from the images below.
Required size for a given span.
The spans in this table are based on a maximum supported rafter span of 16 feet where the supported span is the total horizontal distance spanned by the roof rafters divided in half not the diagonal distance or the length of the rafter.
Hip girder truss a pitch truss with a truncated or flat apex so that it can support more load.
So this table could accommodate a house with a total rafter span or house width of 32 feet.
Live load is weight of furniture wind snow and more.
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.
Hip roofs are more stable than gable roofs and more resistant to strong winds and hurricane.
Dead load weight of structure and fixed loads 15 lbs ft 2.
Span for the main rafters measure from outside of wall to outside of wall.
They must must be on the same level.
2 are indicated below.
Span calculator for wood joists and rafters also available for the android os.
Spacing should be interpreted as the centre to centre distance between adjacent parallel members.
Also available for the android os.
1 psf lb f ft 2 47 88 n m 2.
1 ft 0 3048 m.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
Wood beam calculator american wood council website rafter and joist span faq.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
The 1 grade.
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.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.