Maximum Roof Span

1 in 25 4 mm.

Maximum roof span.

When calculating how many panels you need remember that you have overlap the panels by 2 inches so a 6 foot length actually covers an area 5 foot 10 inches long. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. You can order sheets cut to specific lengths ranging from 5 to 45 feet long although it is difficult to handle a panel longer than 16 feet.

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. Also available for the android os. 2 are indicated below. Live load 20 lbs ft 2 956 n m 2.

Trusses with an asterisk that exceed 14 in height may be shipped in two pieces. Mono used where the roof is required to. As the table shows no 2x8 s meet the span and spacing requirements but a 2x10 with an e of 1 300 000 psi and fb of 1093 psi can span 15 feet 3 inches more than enough. Contact your localalpine trussmanufacturerorofficeformoreinformation.

Bt b tc 6 6 common truss configurations for the most widely designed roof shapes. To achieve maximum indicated spans trusses may require six or more panels. 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. Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.

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. A 2x12 with an e of 800 000 psi and fb of 790 psi also works since it can span 15 feet and 10 inches. 1 ft 0 3048 m. Dead load weight of structure and fixed loads 15 lbs ft 2.

Span calculator for wood joists and rafters also available for the android os. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. 1 psf lb f ft 2 47 88 n m 2. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.