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.
Roof framing spans.
Fill in the parts of the formula that are already known.
1 psf lbf ft2 47 88 n m2.
Rafter spans for southern yellow pine douglas fir and eastern spruce.
Live load is weight of furniture wind snow and more.
Rafter and joist span faq the lengths and sizes of joists vary depending on the species and quality of the lumber used.
For instance a 4 12 pitch denotes a roof rising 4 inches for each 12 inches.
1 in 25 4 mm.
Span calculator for wood joists and rafters also available for the android os.
Interior framing use iprostud in clarkdietrich itools to quickly lookup the interior framing system you need.
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.
These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center.
Range of values in the tables provides allowable spans for all species and grades of nominal 2 inch framing lumber customarily used in construction.
Pitch for a gable roof the most common is generally 1 4 or 1 3.
Allowable limiting heights spans contact clarkdietrich technical services at 888 437 3244 for any questions on tables below.
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.
L stands for the span of the beam in feet.
Dead load weight of structure and fixed loads 15 lbs ft2.
Pitch also has its own denotation determined by the rise in inches in 12 inches.
The tables below give maximum spans for rafters and beams.
Live load 20 lbs ft2 956 n m2 maximum span ft in nominal size.
So this table could accommodate a house with a total rafter span or house width of 32 feet.
Prostud limiting height charts new clarkdietrich itools structural stud lookup tool interior wall heights w structural framing interior.
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.
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.
The calculated spans assume fully supported members.
1 ft 0 3048 m.
Which is equal to 1 4 or 1 3 the total span of the building not counting any overhang.
The total load is 4 000 pounds.
