Lumber Span Tables 2x4 Flat Roof Rafters

Tables w 1 and w 2 of design values for joists and rafters a supplement to these span tables provide such values for the most commonly used.

Lumber span tables 2x4 flat roof rafters. Spacing your 2 4 shed rafters at 24 on center limits the width of your roof. Live load is weight of furniture wind snow and more. 2 4 rafters can span up to 7. 2 are indicated below.

Strength live load of 30 psf plus dead load of 10 psf determines the required bending design value. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. Also available for the android os. Span calculator for wood joists and rafters also available for the android os.

1 ft 0 3048 m. 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. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. For heavy loads 2x4s can span up to 5.

For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. 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. View joist rafter tables. Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size.

Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Permitted for intermediate spans and design values. Deflection for 30 psf live load. For light load roofs 24 o c.

Lumber design values use of these span tables requires reference to the applicable design values for the various species and grades of lumber. Dead load weight of structure and fixed loads 15 lbs ft 2. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. 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.

1 psf lb f ft 2 47 88 n m 2. 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.