Roof Framing Spans

These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center.

Roof framing spans.

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. Dead load weight of structure and fixed loads 15 lbs ft2. 1 psf lbf ft2 47 88 n m2. Range of values in the tables provides allowable spans for all species and grades of nominal 2 inch framing lumber customarily used in construction.

For instance a 4 12 pitch denotes a roof rising 4 inches for each 12 inches. Span calculator for wood joists and rafters also available for the android os. 1 ft 0 3048 m. Pitch for a gable roof the most common is generally 1 4 or 1 3.

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. L stands for the span of the beam in feet. The tables below give maximum spans for rafters and beams. Rafter spans for southern yellow pine douglas fir and eastern spruce.

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. Live load 20 lbs ft2 956 n m2 maximum span ft in nominal size. Prostud limiting height charts new clarkdietrich itools structural stud lookup tool interior wall heights w structural framing interior. Interior framing use iprostud in clarkdietrich itools to quickly lookup the interior framing system you need.

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 total load is 4 000 pounds. The calculated spans assume fully supported members. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.

Which is equal to 1 4 or 1 3 the total span of the building not counting any overhang. Also available for the android os. Rafter and joist span faq the lengths and sizes of joists vary depending on the species and quality of the lumber used. Allowable limiting heights spans contact clarkdietrich technical services at 888 437 3244 for any questions on tables below.

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. Live load is weight of furniture wind snow and more. Pitch also has its own denotation determined by the rise in inches in 12 inches. In the example the beam spans the 10 foot width of the roof.